Plant Breeding Reviews - Raspberry Breeding and Genetics (Volume 32)

PLANT BREEDING REVIEWS Volume 32 Raspberry Breeding and Genetics

edited by

Jules Janick Purdue University

PLANT BREEDING REVIEWS Volume 32

Plant Breeding Reviews is sponsored by: American Society for Horticultural Science Crop Science Society of America Society of American Foresters National Council of Commercial Plant Breeders International Society of Horticultural Science

Editorial Board, Volume 32 Harvey K. Hall Kim E. Hummer

PLANT BREEDING REVIEWS Volume 32 Raspberry Breeding and Genetics

edited by

Jules Janick Purdue University

Copyright # 2009 by Wiley-Blackwell. All rights reserved. Wiley-Blackwell is an imprint of John Wiley & Sons, Inc., formed by the merger of Wiley’s global Scientific, Technical, and Medical business with Blackwell Publishing. Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400, fax 978-750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, 201-748-6011, fax 201-748-6008, or online at http://www.wiley.com/ go/permission. Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages. For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at 877-762-2974, outside the United States at 317-572-3993 or fax 317- 572-4002. Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com.

Library of Congress Cataloging-in-Publication Data: ISBN 978-0-470-38674-3 ISSN 0730-2207 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1

Contents

Contributors 1. Dedication: Derek Jennings and Hugh A. Daubeny Berry Breeders Extraordinaire

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Kim E. Hummer, Rex Brennan, S. Nikki Jennings, Brian Williamson, and Harvey K. Hall I. II. III. IV.

Derek Jennings Selected Publications of Derek Jennings Hugh A. Daubeny Selected Publications of Hugh A. Daubeny

2. Raspberry Breeding and Genetics

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Harvey K. Hall, Kim E. Hummer, Andrew R. Jamieson, S. Nikki Jennings, and Courtney A. Weber I. Introduction II. Germplasm Resources, Exploration, and Maintenance III. Breeding Technology IV. Breeding Systems V. Breeding for Specific Characters VI. Achievements and Prospects Acknowledgments Literature Cited

45 75 90 135 153 309 314 315

Subject Index

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Cumulative Subject Index

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Cumulative Contributor Index

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Contributors

Rex Brennan Fruit Breeding Group. Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland Harvey K. Hall Zealand

Shekinah Berries Ltd, 1 Clay Street. Motueka 7120, New

Kim E. Hummer USDA-ARS Clonal Germplasm Repository, 33447 Peoria Road, Corvallis, Oregon, 97330-2521, USA Andrew R. Jamieson Fruit Breeding, Agriculture and Agri-Food Canada, 32 Main Street, Kentville, Nova Scotia, B4N 1J5, Canada S. Nikki Jennings Mylnefield Research Services Ltd, Scottish Crop Research Institute, Invergowrie, Dundee, DD2 5DA, Scotland. Courtney A. Weber Department of Horticultural Sciences, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, USA Brian Williamson Fruit Breeding Group. Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, Scotland

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Derek Jennings

Hugh A. Daubeny

1 Dedication: Derek Jennings and Hugh A. Daubeny Berry Breeders Extraordinaire Kim E. Hummer USDA–ARS Clonal Germplasm Repository 33447 Peoria Road Corvallis, Oregon 97333–2521 USA Rex Brennan, S. Nikki Jennings, and Brian Williamson Fruit Breeding Group Scottish Crop Research Institute Invergowrie, Dundee, DD2 5DA Scotland Harvey K. Hall Shekinah Berries Ltd. 1 Clay Street Motueka 7120, New Zealand I. DEREK JENNINGS, 2 A. Early Years, 2 B. Early Career, 3 C. Scientific Collaborations, 4 D. Career Successes, 5 1. Raspberry 2. Blackberry 3. Hybrid Berries and Other Rubus Fruits 4. Strawberry

Plant Breeding Reviews, Volume 32 Edited by Jules Janick Copyright & 2009 John Wiley & Sons, Inc. 1

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E. Cultivar Releases, 8 1. Raspberry 2. Blackberry 3. Hybrid Berry 4. Purple Raspberry 5. Strawberry F. Current Activities, 15 G. Awards and Honors, 15 II. SELECTED PUBLICATIONS OF DEREK JENNINGS, 16 A. Journal Articles, 16 B. Book Chapters and Books, 20 C. Cultivar Releases and Patent, 21 III. HUGH A. DAUBENY, 21 A. Early Years, 21 B. Early Career, 23 C. Scientific Collaborations, 24 D. Career Successes, 25 E. Cultivar Releases, 27 F. Current Activities, 30 G. Awards and Honors, 32 IV. SELECTED PUBLICATIONS OF HUGH DAUBENY, 33 A. Journal Articles, 33 B. Book Chapters, 36 C. Cultivar Release Notices, 36

This volume of Plant Breeding Reviews is dedicated to two extraordinary breeders who, with a combination of enthusiasm and expertise, have done much to change the raspberry industry. Both led the way in widening the genetic base of Rubus breeding programs and have encouraged international exchange of plant material and information. Their outstanding cultivar releases have foreshadowed the recent successes of the industry and are highly valued by raspberry breeding and growing programs throughout the world. Their collaborations have inspired the next generation of breeders and researchers to share information for international mutual benefit.

I. DEREK JENNINGS A. Early Years Derek Jennings was born in 1929 and grew up in Cardiff, Wales. His association with the principality continued when he obtained his first degree from the University College of Wales in Aberystwyth, in 1950.

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After graduating, Derek went abroad for his first job. He was appointed as plant breeder to the East African Agriculture and Forestry Research Organization, in which capacity he was posted to Tanganyika (now Tanzania). There he worked in the breeding of maize (Zea mays), groundnuts (Arachis hypogaea), and Sorghum, and in 1952 he was given responsibility for the cassava (Manihot esculentum) program. The program started in 1937, and aimed to transfer resistances to two viruses from several tree species into cassava, which has an important role as a staple food crop in eastern Africa. The work was pioneering at the time, and Derek was responsible for introducing the resistant selections, by this time third backcrosses, to native farmers. At this stage, the resistance failed in some parts, and Derek soon found the cause to be host-virus interactions. He also discovered the breeding combinations that restored the resistance. During this early period in his career, Derek traveled throughout Tanzania lecturing in Swahili. He is regarded as an authority on cassava to this day. Unfortunately, changes in administrative affairs led to the discontinuation of the cassava breeding program in 1956, and Derek returned to the United Kingdom the following year. However, before doing so, Derek distributed the elite cassava germplasm he had generated in the breeding program to many African countries to ensure that others could benefit. This generosity of spirit led to Derek being invited, in 1975, to work for 6 months at the International Institute of Tropical Agriculture in Nigeria, using the germplasm he had distributed 20 years previously. In 2002 he contributed an invited chapter on cassava breeding for a Commonwealth Agricultural Bureaux International (CABI) reference book. B. Early Career Derek’s moved back to the United Kingdom in 1957 to take up the post of raspberry breeder at the Scottish Horticultural Research Institute, later to become the Scottish Crop Research Institute (SCRI), in Dundee, Scotland. The institute opened in 1953, and the pomology department was under the leadership of Conway Wood when Derek joined. The department’s work was aimed at addressing the decline in raspberry yields caused largely by viral infections in the Tayside area of Scotland. Conway Wood had previously bred raspberries as assistant to Norman Grubb at East Malling before moving to SHRI, and there were four assistants in the group, including Malcolm Anderson, who later became the blackcurrant breeder at SCRI.

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C. Scientific Collaborations Derek formed several key relationships within SCRI. Some of the most significant scientific ones were with the pathologists Brian Williamson and Teifion Jones, with whom he investigated some important interactions between Rubus germplasm and pathogenic fungi and viruses respectively. The development of cane resistance to Botrytis cinerea and identification of new sources of resistance for breeding was two results of these collaborations, together with progress in breeding for resistance to cane blight (Leptosphaeria coniothyrium) and spur blight (Didymella applanata) through the use of mycelial inoculation techniques developed at SCRI. Additionally, genetic control of resistance to raspberry yellow rust (Phragmidium rubiidaei) depended on whether resistance was immune (major gene) or resistant with a slow-rusting response (minor genes), and the interaction of diseases such as yellow rust and cane spot (Elsinoe veneta) was investigated. Derek and collaborators also investigated the apparent association of gene H, controlling cane pubescence, with increased resistance to cane Botrytis and spur blight but increased susceptibility to cane spot, mildew, and yellow rust. Derek and his coworkers believed that the pubescent canes mature at a different rate from the smooth ones, thereby separating the susceptibilities and resistances to the various pathogens. The gene H region of the raspberry genome continues to be analyzed at the molecular level by Julie Graham’s group at SCRI. With Teifion Jones and entomologists at SCRI, Derek both identified and then introgressed several key aphid resistance genes into the SCRI raspberry breeding germplasm. Raspberry breeding was given great importance at SCRI at this time. The subsequent reduction in viral infections in U.K. raspberry plantations was a major boost to the industry; sadly, resistance-breaking strains within the U.K. aphid population have now largely overcome the existing resistance genes, and so the search has begun again for robust sources of resistance at both SCRI and East Malling Research. Derek also worked extensively with fruit agronomists at SCRI, notably the late Murray Cormack. In this collaboration, they achieved significant progress in the development of cultivars amenable to mechanical harvesting. They also developed information about the dormancy cycle of raspberry that is still used today for fruit production outside the main cropping season. Derek was involved with Harry Lawson in work to determine the best means for cane vigor control. This work was the key to the acceptance of ‘Glen Clova’ as the first of

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the new raspberry cultivars from SCRI that ultimately transformed the industry in Scotland. Derek traveled widely in the course of his work at SCRI, particularly to visit collaborators in North America. On one occasion during the cold war, Derek traveled with Peter Waister, also of SCRI, on a private trip to the Soviet Union at their invitation—neither he or his family had any advance knowledge of his itinerary or destination, and the men’s flight to Siberia incurred the displeasure of the U.K. Foreign Office. Derek carried out original research in raspberry breeding and registered at the nearby University of St. Andrews. In 1964 he was awarded a Ph.D. for his thesis entitled ‘‘Breeding and Genetical Analysis of Red Raspberry (Rubus idaeus),’’ supervised by Conway Wood. His relationship with St. Andrews continued with his appointment first as honorary lecturer and later as honorary senior lecturer in the Department of Botany.

D. Career Successes 1. Raspberry. Derek’s work at SCRI covered various aspects of Rubus improvement, but the development of new cultivars for the U.K. industry was his main objective and ultimate achievement. Taking on the breeding of raspberry from David Bird, Derek released his first cultivar, ‘Glen Clova’, in 1969, combining high yields with good processing quality, suiting the Scottish industry at the time. ‘Glen Clova’ rapidly became the standard cultivar grown in Scotland, and was also successful for early production in the rest of the United Kingdom. Its position as a standard cultivar for the United Kingdom continued to 2000, when the withdrawal of Dinoseb for primocane management led to its replacement by cultivars with less vigorous primocane growth. The next cultivar release from Derek’s program was ‘Glen Isla’, which had fruit firmness derived from the black raspberry Rubus occidentalis via an East Malling selection. Although not commercially successful in its own right, ‘Glen Isla’ was widely used both by Derek and other breeders as a source of fruit firmness. The next real commercial successes were ‘Glen Prosen’ and ‘Glen Moy’, released in 1982. These two cultivars represented real progress in terms of fruit quality, for both the fresh and processing markets. They were also the first spine-free cultivars in the United Kingdom. As a result, they quickly became the new benchmark for high-quality fruit and are still grown today, albeit on a greatly reduced scale. ‘Glen Moy’ was of particular interest, due to

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its early ripening character, while ‘Glen Prosen’ produced firm fruit with good machine-harvesting ability. The latter cultivar was used widely in breeding and consequently has had a high impact beyond the SCRI program. In his breeding work, a recurring theme is Derek’s great willingness to share germplasm. This led to some important long-term collaborations with other breeders, notably Hugh Daubeny in Canada (‘Glen Prosen’ was used as parental material in the development of ‘Tulameen’), Harvey Hall in New Zealand (SCRI breeding material has featured in the background of many cultivar releases from the Institute of Horticulture and Food of New Zealand Ltd., HortResearch), and the late Graeme McGregor in Australia. In 1985 Derek accepted an invitation to work for 6 months in Victoria, Australia, to study problems relating to raspberry production in a climate warmer than Scotland. During this time he made a major contribution to the breeding program there, particularly in gaining an understanding of the disorder known as blind bud, which is related to the plants’ dormancy cycle in the Australian climate. In 1985 Derek released the cultivars ‘Glen Lyon’ and ‘Glen Garry’ from the SCRI program. Although neither was as successful as his previous releases within the United Kingdom, ‘Glen Lyon’ has become the major cultivar in Spain. This is due largely to its ability to withstand markedly different climatic conditions, together with its firm fruit inherited from ‘Glen Prosen’ and other sources, which makes it ideal for shipping back to other markets, notably the United Kingdom during the period from January to April every year. ‘Glen Lyon’ was originally selected for moderate vigor due to the withdrawal of vigor control chemicals in the United Kingdom, and its success in Spain was not foreseen at the time of release. At this time, Derek’s interaction with Hugh Daubeny in North America was continuing to give benefits to both parties, and ‘Glen Lyon’ has one of Hugh’s cultivars, ‘Haida’, as a grandparent. During his time at SCRI, Derek oversaw the growth of the fruit breeding group at SCRI, and by the time of his retirement in 1989, he was head of the Soft Fruit Genetics Department. In 1994 a group of four cultivars were released from the raspberry breeding program: ‘Glen Magna’, ‘Glen Ample’, ‘Glen Rosa’, and ‘Glen Shee’. Clearly Derek had a pivotal role in their development. Of this group, the most successful cultivar has been ‘Glen Ample’, which in recent years has become the leading cultivar in the United Kingdom and one of only two-main season cultivars, along with ‘Tulameen’, that is accepted by U.K. multiple retailers at the present time. The release of ‘Glen Ample’

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coincided with a major change in emphasis for raspberry production in Scotland: The largely processing market was generally supplanted by production of high-quality fruit for fresh consumption. The ‘Glen Ample’ cultivar is strongly preferred for its flavor and agronomic traits. After retiring from SCRI, Derek moved to southeastern England, where he formed a partnership with Simon Brice, a leading grower there, through the company Medway Fruits. This gave Derek the opportunity to continue his fruit breeding activities across a broader spectrum of fruits. He concentrated on primocane-fruiting raspberries, instead of the summer-fruiting types previously developed, trailingtype blackberries rather than European types, and strawberries. While each of the Rubus cultivars from SCRI are readily identifiable by the ‘Glen’ prefix, Derek’s new position enabled him to acknowledge the support of his wife Joan and other female members of his family. In 1994, his first release, the raspberry ‘Joan Squire’, challenged the U.K. industry standard for primocane types, ‘Autumn Bliss’. Further releases followed, such as ‘Terri-Louise’ in 1996, ‘Joan J’ in 1999, and ‘Joan Irene’ and ‘Marcela’, both in 2004. Of these, ‘Joan J’ has a significant following in the home garden market, while ‘Terri-Louise’ was for a time marketed as a premium cultivar by one of the main U.K. supermarket chains, due to its very large fruit size. Some of these more recent releases have proved to be popular outside of the United Kingdom; for example, ‘Joan Irene’ is grown commercially in Chile at the present time, and ‘Marcela’ is grown in both Chile and Mexico. 2. Blackberry. In 1988 Derek released the spine-free blackberry ‘Loch Ness’, which has had considerable commercial success worldwide and is still grown extensively in Europe. The semi-erect habit makes ‘Loch Ness’ relatively easy to manage, and the shelf life was also an improvement on existing types at the time of release. After leaving SCRI, Derek concentrated on trailing blackberries of the North American type, and from Medway Fruits he released ‘Adrienne’ in 1995 and ‘Helen’ in the following year. The latter proved the most successful, giving high yields of early fruit. 3. Hybrid Berries and Other Rubus Fruits. Derek’s interest in the various sections of Rubus led him to experiment with hybrid berry production, and from a tetraploid raspberry crossed with ‘Aurora’ blackberry he selected the ‘Tayberry’, released from SCRI in 1979. With its aromatic qualities and unique flavor, ‘Tayberry’ was a big commercial success in both the United Kingdom and North America, particularly with home garden and self-pick growers. Even now, almost 30 years

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after its release, it remains a readily identifiable SCRI product for the general public in the United Kingdom. From a cross between ‘Tayberry’ and a sister seedling, ‘Tummelberry’ was released in 1983 but never reached the popularity of ‘Tayberry’. An improved spine-free ‘Tayberry’ was discovered by Derek in 1996 in a Buckinghamshire allotment, and this was released under the name ‘Buckingham Tayberry’. The spineless purple raspberry, ‘Glen Coe’, a diploid from a cross between ‘Glen Prosen’ and a spineless black raspberry, was released in 1988 and attracted interest from the processing market due to its intense color. Derek developed the spineless black raspberry by introgressing spinelessness from the old raspberry cultivar ‘Burnetholm’ into black raspberry types through crossing, backcrossing, selfing, and sib crossing. Further progress has been made in developing spineless black raspberry types from this germplasm by HortResearch, which released the black raspberry ‘Hortberry1’ under the trademark name ‘Ebony’. 4. Strawberry After leaving SCRI, Derek also brought his expertise to the breeding of strawberry for Medway Fruits, and a number of cultivars were released. ‘Christine’ was released in 2000, and crops earlier than the U.K. standard, ‘Elsanta’; it also has fruit quality acceptable to the supermarkets. As a result, almost 500,000 plants were sold in the United Kingdom in 2007. E. Cultivar Releases 1. Raspberry ‘Glen Clova’ 1969. The origin of this cultivar is complex. It was derived from ‘Burnetholm’, ‘Lloyd George’, ‘Malling Exploit’, ‘Malling Jewel’, ‘Newburgh’, and ‘Preussen’. The cross was performed in 1960; it was selected in 1963 and tested as M9. It has an early and extended season. It produces medium-size conical fruit, of medium-light red color. It is dusty, with moderate firmness and vigorous spreading canes. It is productive and susceptible to leaf spot virus. When grown commercially ‘Glen Clova’ was very good for jam and canning but less popular for frozen or fresh, perhaps due to its slightly acid flavor. ‘Glen Isla’ 1974. The origin of this cultivar is complex. It was derived from ‘Burnetholm’, ‘Cumberland’ black raspberry, ‘Lloyd George’, ‘Malling Jewel’, ‘Malling Landmark’, and ‘Norfolk Giant’. The cross was performed in 1960; it was selected in 1963 and tested as M14. It is a late season cultivar, with round-conical orange-red fruit with regular,

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small, firm, and cohesive drupelets. It is moderately acid when fresh, but jam is good although slightly acid when grown in Scotland. Fruit acidity was markedly reduced in New Zealand and the Pacific Northwest of the United States and Canada. Cane growth was vigorous and plentiful but they spread into the alleyways early in the season. ‘Glen Esk’. This cultivar was never formally released but trialed widely around the world. Its origin is complex. It was derived from ‘Burnetholm’, ‘Cumberland’ black raspberry, ‘Lloyd George’, ‘Malling Exploit’, ‘Malling Jewel’, and the gene L1 mutant of ‘Malling Jewel’. It was selected in 1969, evaluated in Scotland as M31 and internationally as ‘Glen Esk’. It fruits in late midseason, with a very large long conical fruit with pale orange-red color, with large drupelets and seed and weak flavor. The appearance ‘Glen Esk’ fruit in a punnet was outstanding, but it was not suitable for processing. Canes elongated early, very erect, very vigorous, tall, thick at the base, and grew in adequate numbers. ‘Glen Moy’ 1981. The origin of this cultivar is complex. It was derived from ‘Burnetholm’, ‘Cumberland’ black raspberry, ‘Glen Clova’, ‘Devon’, ‘Lloyd George’, ‘Malling Exploit’, ‘Malling Jewel’, ‘Malling Landmark’, ‘Newburgh’, and ‘Norfolk Giant’. The cross was made in 1972; it was selected in 1976 and tested as SCRI 7210/204. It is an earlyseason cultivar, with good-quality fruit, vigorous canes, spine free, erect, productive, moderately hardy. It contains A1 resistance to Amphorophora idaei and is susceptible to midge blight, leaf spot virus, Phytophthora root rot, and Rubus bushy dwarf virus (RBDV). ‘Glen Moy’ has been widely used parent for earliness and for contribution to earliness in the development of primocane-fruiting cultivars. ‘Glen Prosen’ 1981. The origin of this cultivar is complex. It is derived from ‘Burnetholm’, ‘Cumberland’ black raspberry, ‘Devon’, ‘Lloyd George’, ‘Malling Jewel’, ‘Malling Landmark’, ‘Newburgh’, ‘Norfolk Giant’, and ‘Preussen’. The cross was made in 1968; it was selected in 1976 and tested as SCRI 6820/54. It is a late-season, large round berry with very large chunky drupelets, spineless, with upright canes, moderate vigor, and is hardy for Scotland. It contains A1 resistance to Amphorophora idaei and is susceptible Phytophthora root rot and RBDV. ‘Glen Prosen’ has gained most significance as the parent of the very successful fresh-market cultivar ‘Tulameen’. ‘Glen Yarra’ 1995. This cultivar is a sister seedling of ‘Glen Prosen’. The cross was made in 1968; it was selected in 1976 and tested as SCRI

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6820/64. The cultivar was introduced by G. R. McGregor, of the Institute for Horticultural Development, Melbourne, Australia. It is a midseason, medium-large firm fruit of medium-red color. It is dusty, vigorous, with upright spineless canes, relatively few new primocanes, and relatively low chilling requirement. It is susceptible to Phytophthora root rot. ‘Glen Yarra’ performed well in trials in other parts of the world but was inferior to ‘Glen Prosen’ in most places so it was not released beyond Australia. ‘Glen Garry’ 1990. ‘Malling Delight’  SCRI 7331/1 (SCRI 703/ 36  ‘Glen Prosen’), SCRI 703/36, is of complex origin, derived from ‘Burnetholm’, ‘Cumberland’ black raspberry, ‘Devon’, ‘Lloyd George’, ‘Malling Jewel’, ‘Malling Landmark’, ‘Norfolk Giant’, and ‘Pyne’s Royal’. SCRI 7331/1 contained gene L1 from a mutant ‘Malling Jewel’ selection used in breeding at SCRI. The cross was made in 1975, and it was tested as 7518E6. The cultivar is early to midseason, spineless, very large fruit size due to the presence of the unstable gene L1 . Plants not containing gene L1 could be identified in the vegetative stage by smaller stipules and less serrated leaves. The fruit is long-conic, firm, slightly pale in color, has excellent flavor, and is suited to niche fresh market and home garden use. Plants are high yielding with moderate vigor but with long, strong fruiting laterals. ‘Glen Garry’ carries gene A1 conferring resistance to two strains of the large raspberry aphid but is susceptible to RBDV. ‘Glen Lyon’ 1991. SCRI 7331/1  SCRI 7256–1 (SCRI 6820/35 [sib of ‘Glen Prosen’]  ‘Haida’) is from a cross made in 1975, tested as SCRI 7515C5. It is early to midseason, spineless, with bright, glossy medium red color, medium-size fruit, firm, easily removed from the receptacle. It has low sugar content and high acidity in Scotland but good sugar/ acid balance when produced in southern Spain and Portugal. It has good shelf life, limited use for processing but now is grown in significant plantings in southern Spain and Portugal. The plant establishes rapidly and produces medium to high yields. It has easily managed upright growth and moderate vigor and A1 aphid resistance. It is resistant to spur blight and leaf spot virus but susceptible to RBDV. ‘Glen Ample’ 1994. The origin of this cultivar is complex. It is a derivative of ‘Glen Prosen’, ‘Meeker’, ‘Rumiloba’, ‘Carnival’, ‘Malling Jewel’, ‘Burnetholm’, ‘Malling Landmark’, ‘Malling Exploit’, ‘Lloyd George’, and ‘Pyne’s Royal’. The cross was made in 1978, and it was tested as 7815B8. It is a midseason cultivar, with spineless canes, is high

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yielding, and is particularly well adapted to fresh-market production in southern Britain. It has medium to large fruit, bright red, round-conic shape, is firm, and tends to break at collar in wet and cool conditions. It is easily removed from the receptacle and can be machine harvested. Canes are upright and vigorous with long, upright laterals. The cultivar has A1 aphid resistance. This cultivar was released from SCRI with Ronnie McNicol. ‘Glen Magna’ 1994. ‘Meeker’  SC RI 7719B11. The origin of this cultivar is complex. It is derived from ‘Rumiloba’, ‘Glen Isla’, ‘Malling Jewel’, ‘Malling Exploit’, ‘Burnetholm’, ‘Devon’ and ‘Malling Landmark’, ‘Cumberland’ black raspberry, ‘Lloyd George’, ‘Norfolk Giant’, and ‘Pyne’s Royal’. The cross was made in 1980; it was tested as 8032A3. The cultivar is late season, very high yielding, with very large fruit, deep red color, long conic shape, and excellent uniform appearance. It is machine-harvestable in some environments. It has excellent flavor with similarities to ‘Glen Moy’ and ‘Meeker’. It is suitable for the fresh market and processing, especially freezing. It has upright, vigorous canes with few spines. The cultivar has A1 aphid resistance and is resistant to RBDV. This cultivar was released from SCRI with Ronnie McNicol. ‘Glen Rosa’ 1994. This cultivar is a sib of ‘Glen Ample’. The cross was made in 1978; it was tested as SCRI 7815A12. It is a midseason, spineless cultivar, with fairly good flavor for processing. It is less suited for the fresh market. It has moderate vigor and production, is moderately upright, and it is adapted for machine harvest. It contains gene H, giving resistance to spur blight and cane Botrytis, and gene A10, giving resistance to four strains of the large European aphid. It is resistant to RBDV. This cultivar was released from SCRI with Ronnie McNicol. ‘Glen Shee’ 1994. The origin of this cultivar is complex. It is derived from ‘Rumiloba’, ‘Burnetholm’, ‘Glen Clova’, ‘Carnival’, ‘Cumberland’ black raspberry, ‘Devon’, ‘Lloyd George’, ‘Malling Exploit’, ‘Malling Jewel’, ‘Malling Landmark’, ‘Newburgh’, ‘Norfolk Giant’, and ‘Pyne’s Royal’. The cross was made in 1980; it was tested as SCRI 8044C9. It is a midseason cultivar with moderate yield and is spineless. Fruit are slightly pale, firm, fleshy, slightly weak skin, prone to wind rub, have a moderate flavor, and are not adapted to machine harvest. Canes are vigorous and relatively upright. It contains A1 aphid resistance and is susceptible to RBDV. This cultivar was released from SCRI with Ronnie McNicol.

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‘Joan Squire’ 1995. SCRI 8216B6  EMR primocane selection. Fruit ripens 2 weeks later than ‘Autumn Bliss’, 2 weeks before ‘Heritage’. This cultivar has good shelf life, excellent flavor, attractive red color with some gloss, no tendency to get a purple-blue tinge. It yields firm, cohesive fruit with skin strength nearly as good as ‘Heritage’. It is more productive than ‘Autumn Bliss’ or ‘Heritage’. It has numerous spineless canes and a spreading growth habit that needs support as the fruit ripens. ‘Terri-Louise’ 1996. ‘Glen Moy’  ‘Autumn Bliss’. Primocane fruit begins to ripen in August in southern England and will crop until mid-December under plastic tunnels. A very early spring crop is produced on overwintered canes. Fruit are very large; they have an attractive red color that darkens when overripe. The flesh texture is very firm, skin strength is weak, and flavor is excellent. It is susceptible to RBDV. ‘Joan J’ 1999. ‘Terri-Louise’  ‘Joan Squire’. This cultivar produces high yields of large fruit, mean 5 g, ripening in early August. Fruit has fleshy texture and is quite dark, with good flavor. The cultivar has spine-free canes and an erect vigorous growth habit. The combination of weak fruit skin and tendency to darken requires picking daily rather than on alternate days. It is mainly of interest to home garden and selfpick growers. ‘Joan Irene’ 2004. ‘Joan J’  (selection of complex origin which also has ‘Dinkum’ in its background). ‘Joan Irene’ produces medium-late primocane fruit that ripen in southern England in August through to November. Fruit is a bright, midred that darkens if not picked regularly. Fruit skin strength is good, as is the shelf life, and large fruit size is maintained late into the fruiting season. Plants are very vigorous with spine-free stout canes. ‘Marcela’ 2004. ‘Autumn Bliss’  ‘Joan Squire’. This is a primocanefruiting cultivar with an early harvest season, up to 2 weeks earlier than ‘Autumn Bliss’ in some environments. Fruit are very firm, lighter red than ‘Autumn Bliss’, and have a strong gloss. Medium force is required for fruit removal, and shelf life and transportation ability are excellent. Growth is strong and is nearly upright. 2. Blackberry ‘Loch Ness’ 1988. This cultivar has a complex parentage, from tetraploid North American cultivars and SCRI breeding lines. It crops over a long period, ripening around 50% of its yield in August under

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U.K. conditions. It has vigorous growth with spine-free semi-erect shoots. The fruiting laterals usually are about 30 cm long, strong but flexible and with white flowers. The cultivar produces high yields of large, glossy black blunt-conical fruit that are firm and with pleasantly sharp flavor. It has excellent storage capability. ‘Adrienne’ 1995. ‘Silvan’  unnamed selection. This cultivar is selected for spine-free habit and high yield potential. Cropping season is earlier than ‘Loch Ness’ and other European blackberries, from early July onward, with firm, long fruits of around 6 g. Growth is vigorous, with a trailing habit. ‘Helen’ 1996. ‘Silvan’  unnamed selection. This cultivar is early ripening, often the first of the U.K. season. Canes are spine-free, with moderate vigor and trailing habit. Fruits are similar in size to ‘Adrienne’, but skin strength is not as good. 3. Hybrid Berry ‘Tayberry’ 1979. This cultivar is from the tetraploid SCRI raspberry breeding line 626/67  ‘Aurora’ blackberry. It has vigorous shoots produced in moderate to high numbers, spreading in young plants but becoming semi-erect later. It has long laterals, up to 30 cm, bearing very large conical purple berries with high drupelet number. Fruit is firm, slightly glossy, and highly flavored with aromatic quality. Plug remains with fruit when it is picked. It is early ripening, comparable to a midseason red raspberry. ‘Buckingham Tayberry’ 1997. This cultivar is a chimeral spineless sport of ‘Tayberry’, where the cell initial for the L1 layer of the growing apex mutated to produce spinelessness. Vegetative propagation produces more spineless plants, but the spinelessness cannot be used for breeding purposes as it is not in the cells that give rise to flowers or fruit. ‘Tummelberry’ 1983. This cultivar is from ‘Tayberry’  SCRI 69102/18; the latter is a selection from the same family as ‘Tayberry’. It has vigorous shoots produced in moderate to high numbers, spreading to slightly more erect than ‘Tayberry’. It has long laterals, medium-large fruit, and red-purple color. The flavor is slightly acid without aromatic characteristics of ‘Tayberry’. Its ripening season is later than ‘Tayberry’, with slightly greater hardiness. It is susceptible to raspberry leaf and bud mite (Phyllocoptes gracilis).

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4. Purple Raspberry ‘Glencoe’ 1989. This cultivar is SCRI 7751C4 (spineless inbred derivative of ‘Munger’ black raspberry and spineless red raspberries from SCRI)  ‘Glen Prosen’). It is a midseason, spine- less purple raspberry, with midsize round-conic fruit. It is dull, purple, very firm, with intense flavor, and is easy to pick with good shelf life. It is selected for specialized processing, fresh market, and home garden uses. Its canes are semi-erect, deep purple, and coated with a conspicuous waxy bloom. Yield is moderate to high. The fruiting laterals are medium length and stiff. It is resistant to Verticillium wilt and not adapted to cold spring weather. 5. Strawberry ‘Claire Maree’. This cultivar is from Cross made in 1995 between unnamed selections, one from Italian and one from U.K. germplasm. The cultivar is notable for its large size, bright color, and excellent flavor but has insufficient shelf life for supermarket sales and was therefore marketed for amateurs. It is now unavailable. ‘Christine’. This cultivar is from a cross made in 1994 between parents of complex origin involving U.K. and Italian germplasm. It crops 7 to 10 days earlier than ‘Elsanta’, the standard U.K. cultivar, and is widely grown for early production. It is vigorous with a tall leaf canopy, and the fruit is well displayed around the plant. It has high skin strength, which gives it a longer shelf-life than ‘Elsanta’. The color is a bright orange and the flavor is good. ‘Christine’ is highly resistant to powdery mildew and Verticillium wilt but susceptible to Phytophthora root rot. Like most early cultivars, its yield is slightly less than that of ‘Elsanta’. ‘Nicola’. This cultivar is from a cross made in 1996 between ‘Symphony’ and a parent selected from Italian germplasm. It is a midseason cultivar, cropping 4 days before ‘Elsanta’. It is notable for its long shelf life and is superior to ‘Elsanta’ for size and good light, bright color. Yields are also above ‘Elsanta’. One of its main values is its high resistance to Phytophthora root rot. It is prone to powdery mildew when grown under plastic but not in the open field. ‘Chelsea Pensioner’. This cultivar is from a cross made in 1998 between unnamed selections, one from U.K. and one from Italian germplasm. It ripens 6 days after ‘Elsanta’, giving a peak of production late in the season, similar in time to ‘Florence’, the standard late variety in the United

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Kingdom. The fruits are notable for their very high flavor, deep red color, and slightly prominent achenes. These qualities are not suitable for supermarket sales, so the variety is being marketed for amateurs. Yields have been good, and no serious disease problems have been reported. F. Current Activities Medway Fruits ceased to operate in 2002, after Simon Brice’s retirement, with a final release of the autumn-fruiting raspberry ‘Brice’ in 2007. However, unknot surprisingly, Derek continued to be in high demand as a breeder, and currently he is working for Redeva Ltd., a subsidiary of the Summer Fruits Company. G. Awards and Honors During his career, Derek has been the recipient of several highly prestigious awards, both in the United Kingdom and abroad. In 1979 he was awarded the Scottish Horticultural Medal by the Royal Caledonian Horticultural Society, in appreciation of outstanding services to Scottish horticulture. Internationally, in 1997 Derek was awarded the Wilder Medal by the American Pomological Society for ‘‘excellence in Rubus breeding,’’ and in 2000 he received the ‘‘Horticologo de Honra: Associacao Portugesa de Horticultura,’’ in Portugal, in recognition of his work as consultant to the Department of Horticulture in that country. In 2001 Derek received the award for Lifetime Achievement at the U.K. Grower of the Year Awards. Derek is a widely published scientist, with almost 100 papers and numerous book chapters. In 1988 Academic Press published his book, Raspberries and Blackberries: Their Breeding, Diseases and Growth, and this volume has become a standard text across a very wide readership, from researchers to home gardeners—a true testament to Derek’s ability to communicate his subject and expertise. Derek has passed his boundless enthusiasm for his work and wide knowledge on to numerous young emerging fruit breeders, several of whom spent happy and productive sabbatical periods at SCRI. He remains one of the most respected figures in fruit breeding and is still active—his latest selection, as yet unnamed, was awarded joint first prize at the 2007 National Fruit Show. Looking back over the 50 years of Derek’s career in fruit breeding and research, his work provides a benchmark for the successful application of scientific advances into the reality of commercial cultivars, many of which will be grown for some time to come.

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II. SELECTED PUBLICATIONS OF DEREK JENNINGS A. Journal Articles Anthony, V. M., B. Williamson, D. L. Jennings, and R. C. Shattock. 1986. Inheritance of resistance to yellow rust (Phragmidium rubi-idaei) in red raspberry. Ann. Appl. Biol. 109:365–374. Daubeny, H. A., P. B. Topham, and D. L. Jennings. 1968. A comparison of methods for analyzing inheritance data for resistance to red raspberry powdery mildew. Can. J. Genet. Cytol. 10:341–350. Gooding, H. J., D. L. Jennings, and P. B. Topham. 1975. A genotype-environment experiment on strawberries in Scotland. Heredity 34:105–115. Hall, H. K., D. L. Jennings, P. Rosati, and D. Gaggioli. 1988. Inheritance of thornlessness from tissue culture originated loganberries. Acta Hort. 224:369. Hershey, C. H., and D. L. Jennings. 1992. Progress in breeding cassava for adaptation to stress. Pl. Breeding Abstr. 62: 823–831. Jennings, D. L. 1957. Further studies in breeding cassava for virus resistance. East African Agr. J. 22:213–219. Jennings, D. L. 1959. Manihot melanobasis Mull. Arg.—a useful parent for cassava breeding. Euphytica 8:157–162. Jennings, D. L. 1960a. Observations on virus diseases of cassava in resistant and susceptible varieties. I. Mosaic disease. Empire J. of Exp. Agric. 28:23–34. Jennings, D. L. 1960b. Observations on virus diseases of cassava in resistant and susceptible varieties. II. Brown streak disease. Empire J. of Exp. Agric. 28:261– 270. Jennings, D. L. 1961. Mutation for larger fruit in the raspberry. Nature 191:302–303. Jennings, D. L. 1962a. Some aspects of breeding for disease resistance in the raspberry. Proceedings of the 16th International Hort. Congress, Brussels, Belgium, III:87–91. Jennings, D. L. 1962b. Some evidence on the influence of the morphology of raspberry canes upon their liability to be attacked by certain fungi. Hort. Res. 1:100–111. Jennings, D. L. 1963a. Preliminary studies on breeding raspberries for resistance to mosaic disease. Hort. Res. 2:82–96. Jennings, D. L. 1963b. Some evidence on the genetic structure of present-day raspberry varieties and some possible implications for further breeding. Euphytica 12:229– 243. Jennings, D. L. 1963c. Variation in pollen and ovule fertility in varieties of cassava, and the effect of interspecific crossing on fertility. Euphytica 12:69–76. Jennings, D. L. 1964a. Plant breeding and genetic studies in the red raspberry Rubus idaeus L. Ph.D. thesis, Univ. St. Andrews, Scotland. Jennings, D. L. 1964b. Some evidence of population differentiation in Rubus idaeus L. New. Phytol. 63:153–157. Jennings, D. L. 1964c. Studies on the inheritance in the red raspberry of immunities from three nematode-borne viruses. Genetica 34:152–164. Jennings, D. L. 1964d. Two further experiments on flower bud initiation and cane dormancy in the red raspberry (var. Malling Jewel). Hort. Res. 4:14–21. Jennings, D. L. 1966a. The manifold effects of genes affecting fruit size and vegetative growth in the raspberry, I: Gene l1 . New. Phytol. 65:176–187. Jennings, D. L. 1966b. The manifold effects of genes affecting fruit size and vegetative growth in the raspberry, II: Gene l2 New. Phytol. 65:188–191.

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Jennings, D. L. 1967a. Balanced lethals and polymorphism in Rubus idaeus. Heredity 22:465–479. Jennings, D. L. 1967b. Observations on some instances of partial sterility in red raspberry cultivars. Hort. Res. 7:116–122. Jennings, D. L. 1970a. Cassava in Africa. Field Crop Abstracts 23:271–278. Jennings, D. L. 1970b. Cassava in East Africa. Proc. 2nd Int. Symp. on Tropical Root and Tuber Crops: 64–65. Jennings, D. L. 1971a. Some genetic factors affecting the development of endocarp, endosperm and embryo in raspberries. New Phytol. 70:885–895. Jennings, D. L. 1971b. Some genetic factors affecting fruit development in red raspberries. New Phytol. 70:361–370. Jennings, D. L. 1971c. Some genetic factors affecting seedling emergence in raspberries. New Phytol. 70:1103–1110. Jennings, D. L. 1972. Aberrant segregation of a gene in the raspberry and its association with effects on seed development. Heredity 29:83–90. Jennings, D. L. 1974a. Aspects of fruit and seed development which affect the breeding behaviour of Rubus species. Genetica 45:1–10. Jennings, D. L. 1974b. Breeding raspberries for machine harvesting. Scottish Hort. Research Inst. Ann. Bull. 8:34–37. Jennings, D. L. 1975a. Aspects of fruit and seed development which affect the breeding behaviour of Rubus species. Genetica 45:315–324. Jennings, D. L. 1975b. An evaluation of some sources of resistance to two virus diseases of cassava. J. Root Crops 1:19–23. Jennings, D. L. 1977. Somatic mutation in the raspberry. Hort. Res. 17:61–63. Jennings, D. L. 1978. The blackberries of South America—an unexplored reservoir of germplasm. Fruit Var. J. 32:61–63. Jennings, D. L. 1979a. Genotype-environment relationships for ripening time in blackberries and prospects for breeding an early ripening cultivar for Scotland. Euphytica 28:747–750. Jennings, D. L. 1979b. The occurrence of multiple fruiting laterals at single nodes of raspberry canes. New Phytol. 82:365–374. Jennings, D. L. 1979c. Resistance to Leptosphaeria coniothyrium in the red raspberry and some related species. Ann. Appl. Biol. 93:319–326. Jennings, D. L. 1980. Recent progress in breeding raspberries and other Rubus fruits at the Scottish Horticultural Research Institute. Acta Hort. 112:109–116. Jennings, D. L. 1981. A hundred years of Loganberries. Fruit Var. J. 35:34–37. Jennings, D. L. 1982a. Further evidence on the effects of gene H, which confers cane hairyness, on resistance to raspberry diseases. Euphytica 31:953–956. Jennings, D. L. 1982b. Resistance to Didymella applanata in red raspberry and some related species. Ann. Appl. Biol. 101:331–337. Jennings, D. L. 1983. Inheritance of resistance to Botrytis cinerea and Didymella applanata in canes of Rubus idaeus, and relationships between these resistances. Euphytica 32:895–901. Jennings, D. L. 1984. A dominant gene for spinelessness in Rubus, and its use in breeding. Crop Res. 24:45–50. Jennings, D. L. 1986a. Breeding soft fruit for processing. Acta Hort. 194:21–29. Jennings, D. L. 1986b. Breeding for spinelessness in blackberries and blackberry-raspberry hybrids: A review. Acta Hort. 183:59–66. Jennings, D. L. 1987a. Host-virus relationships of resistant cassava and African cassava mosaic virus, and some implications for breeding and disease control. Proc. Int. Conf. on

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African Cassava Mosaic Disease and Its Control, Yamoussoukro, Cote d’Ivoire, May 1987: 170–174. Jennings, D. L. 1987b. Some effects of secondary dormancy and correlative inhibition on the development of lateral buds of raspberry canes (Rubus idaeus L.). Crop. Res. (Hort. Res.) 27:119–129. Jennings, D. L. 1988. Scottish blackberry with US background. Grower (March): 38–39. Jennings, D. L. 1989a. Blackberry plant-Loch Ness cultivar. United States Plant Patent PP 6,782. Washington D.C. Jennings, D. L. 1989b. The use of multivariate analyses for study of autumn-fruiting strawberries. Acta Hort. 265:91–96. Jennings, D. L. 1991a. Rubus Breeding—recent progress and problems. Plant Breeding Abstracts 61:753–758. Jennings, D. L. 1991b. Techniques for extending the cropping season of strawberries, raspberries and blackberries and the implication of these techniques and new cultivars for raspberry and blackberry production in Australia. Proc. National Conf. of the Australian Berry Growers Association, Hobart, Tasmania, Australia. Jennings, D. L. 1993. Mutations in Rubus: Their value in breeding and problems for propagation. Acta Hort. 352:353–360. Jennings, D. L. 1994. Breeding for resistance to African cassava mosaic geminivirus in East Africa. Trop. Sci. 34:110–122. Jennings, D. L. 1995. ‘Glen Moy’ Red Raspberry. Fruit Var. J. 49:2–4. Jennings, D. L. 1997. ‘Joan’ doubles the options. Grower (July 17):32. Jennings, D. L. 2002. Breeding primocane-fruiting raspberries at Medway Fruits—progress and prospects. Acta Hort. 585:85–89. Jennings, D. L. 2003. Blackberries and related fruits. Encyclopedia of Food Sciences and Nutrition. pp.546–550. Jennings, D. L., and E. Brydon. 1989a. Further studies on breeding for resistance to Botrytis cinerea in red raspberry canes. Ann. Appl. Biol. 115:507–513. Jennings, D. L., and E. Brydon. 1989b. Further studies on resistance to Leptosphaeria coniothyrium in the red raspberry and related species. Ann. Appl. Biol. 115:499– 506. Jennings, D. L., and E. Brydon. 1990. Variable inheritance of spinelessness in progenies of a mutant of the red raspberry cv. Willamette. Euphytica 46:71–77. Jennings, D. L., and E. Carmichael. 1975a. A dominant gene for yellow fruit in the raspberry. Euphytica 24:467–470. Jennings, D. L., and E. Carmichael. 1975b. Resistance to grey mould (Botrytis cinerea Fr.) in red raspberry fruits. Hort. Res. 14:109–115. Jennings, D. L., and E. Carmichael. 1975c. Some physiological changes occurring in overwintering raspberry plants in Scotland. Hort. Res. 14:103–108. Jennings, D. L., and E. Carmichael. 1979. Colour changes in frozen blackberries. Hort. Res. 19:15–24. Jennings, D. L., and E. Carmichael. 1980. Anthocyanin variation in the genus Rubus. New Phytol. 84:505–513. Jennings, D. L., and M. R. Cormack. 1969. Factors affecting the water content and dormancy of overwintering raspberry canes. Hort. Res. 9:18–25. Jennings, D. L., and A. Dale. 1982. Variation in the growth habit of red raspberries with particular reference to cane height and node production. J. Hort. Sci. 57:197–204. Jennings, D. L., and L. Evans, 1990. Maintaining plant health through certification schemes and hygienic methods of propagation. Proc. Nat. Conf. of the Austr. Berry Growers Assoc.

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Jennings, D. L., and R. Ingram. 1983. Hybrids of Rubus parviflorus (Nutt.) with raspberry and blackberry, and the inheritance of spinelessness derived from this species. Crop Res. 23:95–101. Jennings, D. L., and A. T. Jones. 1986. Immunity from raspberry vein chlorosis virus in raspberry and its potential for control of the virus through plant breeding. Ann. Appl. Biol. 108:417–422. Jennings, D. L., and A. T. Jones. 1989. Further studies on the occurrence and inheritance of resistance in red raspberry to a resistance-breaking strain of raspberry bushy dwarf virus. Ann. Appl. Biol. 114:317–323. Jennings, D. L., and G. R. McGregor. 1988a. Resistance to cane spot (Elsinoe veneta) in the red raspberry and its relationship to yellow rust (Phragmidium rubi-idaei). Euphytica 37:173–180. Jennings, D. L., and R. J. McNicol. 1989a. Black raspberries and purple raspberries should be spine-free and tetraploid. Acta Hort. 262:89–92. Jennings, D. L., and R. J. McNicol. 1989b. Segregation of plants with abnormal flowers in a blackberry breeding programme. Crop Res. 29:51–54. Jennings, D. L., and R. J. McNicol. 1991. Rubus breeding—recent progress and problems. Pl. Breeding Abstr. 61: 753–758. Jennings, D. L., and P. B. Topham. 1971. Some consequences of raspberry pollen dilution for its germination and for fruit development. New. Phytol. 70:371–380. Jennings, D. L., and B. M. Tulloch. 1965. Studies on factors which promote germination of raspberry seeds. J. Expt. Bot. 16:329–340. Jennings, D. L., and B. Williamson. 1982. Resistance to Botrytis cinerea in canes of Rubus idaeus and some related species. Ann. Appl. Biol. 100:375–381. Jennings, D. L., M. M. Anderson, and C. A. Wood. 1964a. Observations on a severe occurrence of raspberry cane death in Scotland. Hort. Res. 4:65–77. Jennings, D. L., M. M. Anderson, and C. A. Wood. 1964b. Two further experiments on flower-bud initiation and cane dormancy in the red raspberry (var. ‘Malling Jewel’). Hort. Res. 4:14–21. Jennings, D. L., E. Carmichael, and J. J. Costin. 1972. Variation in the time of acclimation of raspberry canes in Scotland and Ireland and its significance for hardiness. Hort. Res. 12:187–200. Jennings, D. L., D. L. Craig, and P. B. Topham. 1967. The role of the male parent in the reproduction of Rubus. J. Hered. 22:43–55. Jennings, D. L., A. Dale, and E. Carmichael. 1976. Raspberry and blackberry breeding at the Scottish Horticultural Research Institute. Acta Hort. 60:129–134. Jennings, D. L., H. A. Daubeny, and J. N. Moore. 1991. Blackberries and raspberries (Rubus). In Genetic resources of temperate fruit and nut crops. Acta Hort. 290:331–389. Jennings, D. L., G. R. McGregor, J. A. Wong, and C. E. Young. 1986. Bud suppression (‘‘blind bud’’) in raspberries. Acta Hort. 183:285–289. Jones, A. T., and D. L. Jennings. 1980. Genetic control of the reactions of raspberry to black raspberry necrosis, raspberry leaf mottle and raspberry leaf spot viruses. Ann. Appl. Biol. 96:59–65. Jones, A. T., S. C. Gordon, and D. L. Jennings. 1984. A leaf-blotch disorder of Tayberry associated with the leaf and bud mite (Phyllocoptes gracilis) and some effects of three aphid-borne viruses. J. Hort. Sci. 59:523–528. Jones, A. T., M. J. Mitchell, D. L. Jennings, and S. C. Gordon. 1988. Recent research on viruses and virus-like diseases on Rubus in Scotland. Acta Hort. 186:9–16. Jones, A. T., A. F. Murant, D. L. Jennings, and G. A. Wood. 1982. Association of raspberry bushy dwarf virus with raspberry yellows disease; reaction of Rubus species and cultivars, and the inheritance of resistance. Ann. Appl. Biol. 100:135–147.

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Knight, V. H., D. L. Jennings, and R. J. McNicol. 1989. Progress in the UK raspberry breeding programme. Acta Hort. 262:93–103. McNicol, R. J., B. Williamson, D. L. Jennings, and J. A. T. Woodford. 1983. Resistance to raspberry cane midge (Resseliella theobaldi) and its association with wound periderm in Rubus crataegifolius and its red raspberry derivatives. Ann. Appl. Biol. 103:489–495. Murant, A. F., D. L. Jennings, and J. Chambers. 1973. The problem of crumbly fruit in raspberry nuclear stocks. Hort. Res. 13:49–54. Murant, A. F., A. T. Jones, and D. L. Jennings. 1982. Problems in the control of raspberry bushy dwarf virus. Acta Hort. 129:77–83. Oliveira, P. B., L. L. da Fonseca, and D. L. Jennings. 2004. Summer pruning effect on reproductive yield components of ‘Triple Crown’ blackberry. Acta Hort. 649:277–281. Pool, P. A., R. Ingram, R. J. Abbott, D. L. Jennings, and P. B. Topham. 1981. Karyotype variation in Rubus with particular reference to R. idaeus L. and R. coreanus Miquel. Cytologia 46:125–132. Rosati, P., H. K. Hall, D. L. Jennings, and D. Gaggioli. 1988. A dominant gene for thornlessness obtained from the chimeral thornless Loganberry. HortScience 23:899–902. Thresh, J. M., G. W. Otim-Nape, and D. L. Jennings. 1994. Exploiting resistance to African cassava mosaic resistance. Asp. Appl. Biol. 39:51–60. Williamson, B., and D. L. Jennings. 1986. Common resistance in red raspberry to Botrytis cinerea and Didymella applanata, two pathogens occupying the same ecological niche. Ann. Appl. Biol. 109:581–593. Williamson, B., and D. L. Jennings. 1992. Resistance to cane and foliar diseases in red raspberry (Rubus idaeus) and related species. Euphytica 63:59–70.

B. Book Chapters and Books Jennings, D. L. 1976a. Cassava. pp. 81–90. In: J. Smartt and N. W. Simmonds (eds.), Evolution of crop plants. Longman Group, Essex, UK. Jennings, D. L. 1976b. Raspberries and blackberries Rubus (Rosaceae). pp. 251–254. In: J. Smartt, and N. W. Simmonds (eds.), Evolution of crop plants. Longman Group, Essex, UK. Jennings, D. L. 1978. The inheritance of linked resistances to African cassava mosaic and bacterial blight diseases. ID RC Monograph Series CE-14, Ottawa, Canada. Jennings, D. L. 1987. Crop utilization: Starch crops. In: B. R. Christie (ed.), Handbook of plant science in agriculture. CRC Press Inc. Boca Raton, FL. Jennings, D. L. 1988. Raspberries and blackberries: Their breeding, diseases and growth. Academic Press, London. Jennings, D. L. 1995. Cassava. pp. 128–132. In: J. Smartt and N. W. Simmonds (eds.), Evolution of crop plants, 2nd ed. Longman, London. Jennings, D. L. 1995. Raspberries and blackberries. pp. 429–434. In: J. Smartt and N. W. Simmonds (eds.), Evolution of crop plants, 2nd ed. Longman, London. Jennings, D. L. 2003a. Berries under cover: The southern European experience. In: A. Royal (ed.), Proc. 12th National and 1st Trans-Tasman Berryfruit Conf. Jennings, D. L. 2003b. Raspberry production indoors: managing the variables. In: A. Royal (ed.), Proc.12th National and 1st Trans-Tasman Berryfruit Conf. Jennings, D. L., and M. M. Anderson, 1984. Soft fruit breeding in Scotland. Fruit, Vegetable and Science, pp. 24–25. Jennings, D. L., M. M. Anderson, and R. M. Brennan. 1988. Raspberry and blackcurrant breeding. pp. 135–147. In: A. J. Abbott and R. J. Atkin (eds.), Improving vegetatively propagated crops. Academic Press, London.

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Jennings, D. L., H. J. Gooding, and M. M. Anderson. 1973. Recent developments in soft fruit breeding. In: Fruit present and future 2. Royal Hort. Soc., London. Jennings, D. L., and C. H. Hershey. 1985. Cassava breeding: A decade of progress from international programmes. pp. 89–113. In: G. E. Russell (ed.), Progress in plant breeding. Butterworths, London. Jennings, D. L., and C. Iglesias. 2002. Breeding for crop improvement. pp. 149–166. In: R. J. Hillocks, M. J. Thresh, and A. Bellotti (eds.), Cassava: Biology, production and utilization. CAB Int., Wallingford, UK. Jennings, D. L., and G. R. McGregor. 1988. Some genetic facts which control the number and size of raspberry fruits produced on a raspberry cane. pp. 315–327. In: C. J. Wright (ed.), Manipulation of fruiting, Univ. Nottingham 47th Easter School in Agricultural Science. Butterworths, Sevenoaks, UK. Terry, E. R., and D. L. Jennings. 1976. Symptomatology of cassava mosaic disease and a proposal for further study to categorize the variants. pp. 36–38. In: Procedings of the African cassava mosaic Interdisciplinary Workshop. Muguga (Kenya). IDRC Monograph (ID RC -071c).

C. Cultivar Release Notices and Plant Patents Jennings, D. L. 1978. Plant breeding. New cultivar of hybrid berry—Tayberry. Rep. Scottish Hort. Res. Inst. for 1977: 62–63. Jennings, D. L. 1982a. New raspberry cultivar: Glen Moy. Annu. Report of the Scot. Crop. Res. Inst. for 1981: 71–72. Jennings, D. L. 1982b. New raspberry cultivar: Glen Prosen. Annu. Rep. Scottish Crop. Res. Inst. for 1981: 72–73. Jennings, D. L. 1983a. New cultivar of hybrid Rubus: Tummelberry. Ann. Rep. Scottish Crop. Res. Inst. for 1982: 86–87. Jennings, D. L. 1983b. Two new spine-free raspberries. Fruit Var. J. 37:34–36. Jennings, D. L. 2005. Joan J breeders description. URL: http://www.meiosis.co.uk/fruit/ joan_j.htm. (Accessed: April 14, 2007.) Jennings, D. L. 2006. Notes on a conference entitled Breeding Strawberries and Raspberries for the 21st Century held by Meiosis, July 18, 2006. Jennings, D. L. 2007. Raspberry variety named ‘Marcela’, United States Plant Patent, Washington, D.C. Maidstone, G. B., and Jennings, D. L. 2007. Raspberry variety named ‘Joan Irene’, United States Plant Patent, Washington, D.C. McNicol, R. J., and D. L. Jennings, 2000. Raspberry variety named ‘Glen Ample’, United States Plant Patent, Washington, D.C.

III. HUGH A. DAUBENY A. Early Years Dr. Hugh A. Daubeny was born on December 6, 1931, in Nanaimo, British Columbia (BC) and attended primary school there and in Victoria, where he completed primary school and graduated from Mt. View High School. Both his parents came from the United Kingdom. His father, Hugh C. C. Daubeny, came from England, where he served in the Royal Navy as a

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midshipman during the latter days of the World War I. Between the wars he served in the BC Provincial Police and later in the Royal Canadian Mounted Police. At the beginning of the World War II, in 1939, he was called up to serve in the Royal Canadian Navy (RCN) and was commander of the corvette Nanaimo, part of the fleet of corvettes that escorted convoys in the North Atlantic. After the war he returned to Victoria to serve with the RCMP until his retirement. He died in 1969. Hugh’s mother, Mary, came from Aberdeen in Scotland to visit relatives who had an orchard at Summerland in the Okanagan Valley of BC. There she met and married his father. They lived in the BC interior briefly and then moved to Nanaimo, where they stayed until the early years of the war. The main Pacific base of the RCN was located at Esquimalt, near Victoria and was the home base of the HMCS Nanaimo. Hugh had one younger sister, who died in an air crash in northern British Columbia in the 1960s, while on her way to a teachers’ convention. She taught school at Stewart, BC. at the head of the Portland Canal, on the Alaska border. Hugh’s mother lived in the family home until 1988, when she decided to move to Vancouver to be closer to him and his family. She lived with them for 5 years, until ill health forced her into an extended care in a hospital nearby. She died in 2002, a few days short of her 98th birthday. Both his parents were keen gardeners, similar to so many who came to British Columbia from the United Kingdom between the two world wars. In 1946, after the war, his parents had their first real garden and grew traditional British vegetables: marrow, broad beans, turnips, parsnips, and leeks. His mother never got used to tomatoes, a crop that was almost unheard of during her youth in Scotland. It was ironic that Hugh researched tomatoes as part of his Ph.D. degree program at Cornell University. His mothers loved flowers, especially roses and sweet peas. The family garden had an old patch of raspberries as well as loganberries and, for a few years, ‘Youngberries’, which died out after an unusually cold winter. There was a ‘Bing’ cherry and also a pear and plum tree. For several summers in the mid-1940s, Hugh picked black currants, then ‘Loganberries’ and raspberries at a berry farm in Gordon Head. Gordon Head was renowned for producing quality berries; now it is an upscale residential area. Hugh also picked strawberries, the legendary ‘British Sovereign’ cultivar, for 1 week but was glad when the black currants and cane berries started to ripen. He did not enjoy stooping, but overcame this once he became a strawberry breeder. The family home was near a lovely Garry oak park (Quercus garryana)—relic species distributed from the California and Oregon

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and Washington coasts into southwestern British Columbia). The oaks had a marvelous undergrowth of native plants, such as Erthyronium, Camus, Trillium, and Dodecatheum. Here Hugh had his first experiences with native plants. This was the foundation of Hugh’s obsession with plant conservation in his later years. Unfortunately, only about 10% of the original Canadian Garry oak ecosystem remains: on Vancouver Island, on the Gulf Islands, and in a few sites in the lower mainland of British Columbia. As an undergraduate at the University of British Columbia in the 1950s, Hugh spent one summer working on the vegetable cultivar trials that Agriculture Canada sponsored on the campus. Other summers were spent as a student assistant at Agriculture Canada’s Saanich Experimental Station near his home. He worked with a research scientist who was screening herbicides. Hugh learned about preparing and applying the chemicals and experimental design. After that, though, he decided he was better suited for plant breeding. In 1953 he received his BSA from UBC. His major professor at UBC, Cedric Hornby, had gone to Cornell University, and he persuaded Hugh to accept an assistantship there. Hugh performed his doctoral research on the mechanisms of fruit set of tomatoes under-less-than optimum temperatures and his assistantship research on bacterial blight on dry beans. His major professor was Dr. Henry Munger, the world’s premier vegetable breeder. Hugh obtained his Ph.D. from Cornell in 1958. While at Cornell, he met his future wife, Marian Peterson, a technician in animal science. Marian had a B.S. degree in bacteriology from the University of Utah. They were married in 1959. B. Early Career Hugh was offered positions in the East but decided to accept an offer from Agriculture Canada to establish breeding programs for strawberries and raspberries in coastal British Columbia. The move was facilitated by Charlie J. Bishop, Agriculture Canada’s Program Coordinator for Horticulture Crops. The establishment of field plots at the Pacific Agri-Food Research Center at Agassiz had some unique challenges; the region was reputed to have the highest population of black bears in the world, and they were a dangerous nuisance in his plots. A second problem was people related. As the plots were being planted, the adjacent bush land was being cleared by prisoners from a nearby correctional facility. This was an interesting situation, especially during the summer months, when the assistants, mostly

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female students from UBC, were working. By the late 1960s, Hugh Daubeny was well recognized as an up-and-coming-raspberry and strawberry breeder by scientific community. Hugh and Marian lived in Agassiz until 1973, when the breeding program was moved to the Vancouver Research Station near where Hugh’s collaborators, the plant pathologists and virologists, were stationed. The field plots were relocated near Abbotsford. One plus of the move: There were no bears. Another was that the plots were located in the heart of the berry-growing country. This was in the days before urban encroachment. Unfortunately, recently berry area has diminished there despite an Agriculture Land Reserve designation. C. Scientific Collaborations Hugh’s breeding program flourished in Vancouver under the encouragement of the director, Marvin Weintraub. Research progress was assisted with inputs from the outstanding plant pathologists Bert Pepin and later Andre Levesque; the virologists Dick Stace-Smith, Frances Mellor, and later Bob Martin; and a nematologist Thierry Vrain. Protocols were established for selecting resistance or tolerance to diseases. These included strawberry red stele root rot, fruit rots, and powdery mildew of both crops, raspberry root rot, raspberry spur blight and cane Botrytis and resistance to the North American aphid vector of the raspberry mosaic virus complex. Cooperative research helped to better understanding of raspberry bushy dwarf virus and meadow lesion nematode. The efforts of Dick Stace-Smith and Frances Mellor always assured virus-free planting stock for raspberry and strawberry genotypes, respectively. Inheritance patterns were established for reactions to aphids, powdery mildew, spur blight, and cane Botrytis in raspberry and virus tolerance in strawberry. Hugh also did lot of cooperative work with Jack Freeman from Agassiz on developing cultural and management procedures that enhanced the adaptation of newly developed cultivars. The years at the Vancouver Research Station cemented the outstanding research team of berry crop researchers that flourished in the Pacific Northwest. In 1959 Hugh met two legendary berry crop breeders, Charles ‘‘Chet’’ Schwartz, at Washington State University in Puyallup, and George Waldo, United States Department of Agriculture (USDA) and Oregon State University in Corvallis. Other key breeders later became an integral part of the community: Bruce Barritt followed by Tom Sjulin and then Pat Moore in Washington, and Francis ‘‘Whitey’’ Lawrence and then Chad Finn in Oregon. Throughout the

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Pacific Northwest there was excellent cooperative work among plant pathologists, entomologists, horticulturists, soil scientists, and agronomists such as Peter Bristow, Bob Norton, Perry Crandall, and Carl Shanks in Washington, and Dick Converse in Oregon, and, in later years, Bernadine Strik in Oregon and Jack Freeman, Matt John, and Bill Peters in British Columbia. Hugh’s helpful technical and field crew included Henry Troelsen, Dana Stary, Angela Anderson, and Susan Wahlgren. Hugh’s success as a berry crop breeder was based on combining collaborative friendships and germplasm exchange from many breeding programs as well as from the wild. His well-documented use of the East Malling Research Station (EMRS) and Scottish Crop Research Institutes (SCRI ) germplasm as parents, crossed with his own material, led to the development of a group of cultivars that are commercially important, widely adapted, and have large, high-quality fruit. Hugh has decried the decrease in exchange that has come with widespread patenting of cultivars. His open exchange approach laid the ground to the excellent relationships that exist between the three Pacific Northwest breeding programs today. Hugh’s enthusiasm for cooperation and collaboration has not been limited to North America. He played a significant role in the establishment and development of breeding programs in Australia with Graeme McGregor and in New Zealand, first with Jim Porter and Norm Broadbent of the Ministry of Agriculture and Fisheries (MAF) in Levin, and later with Harvey Hall at the Department of Scientific and Industrial Research (DSIR) and then HortResearch, New Zealand (HRNZ). Hugh has visited these programs several times and kept in contact with each of the breeders until the time of Graeme McGregor’s death in December 2005. Hugh generously supplied germplasm for each program and was active in encouraging publication from and with these breeders. D. Career Successes The greatest success from the strawberry breeding program was ‘Totem,’ the leading cultivar in the Pacific Northwest for more than 30 years. This is probably a record for longevity of any strawberry grown in the region. Only after 2005 did the cultivar begin to succumb to resistance-breaking races of the red stele root rot causal organism, Phytophthora fragariae var. fragariae and changes in the aphidtransmitted virus complex. ‘Totem’ has been used extensively in other breeding programs. Other strawberry cultivars from Hugh’s program include the winter hardy ‘Sumas’ and ‘Nanaimo,’ named after town where he was born and his father’s ship Nanaimo in World War II.

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‘Nanaimo’ produces fruit with an exceptionally high soluble solids content and appealing fresh flavor. Unfortunately, size is not maintained through the season. Hugh was willing to take chances in his breeding efforts. By using wide crosses and indigenous species, Hugh broadened the germplasm base of the strawberry and raspberry breeding programs. This resulted in added disease and insect resistances and improved fruit qualities. Hugh’s cultivar ‘Tulameen’ resulted from the 1980 cross of ‘Nootka’ ‘Glen Prosen’ made in the breeding program at Agriculture and AgriFood Canada’s Pacific Agriculture Research Centre. ‘Nootka’, an earlier release from the program, is noted for its high levels of soluble solids that are well balanced with acid levels. ‘Glen Prosen’ is an exceptionally firm, large-fruited cultivar from the Scottish Crop Research Institute’s program. It owes its firmness to genes obtained from the eastern North America native black raspberry, Rubus occidentalis. These genes were brought into raspberry breeding through pioneering work at Horticulture Research International, at East Malling in England. ‘Tulameen’ was initially selected in the seedling stage for resistance to the common strain of the aphid vector (Amphorophora agathonica) of the raspberry mosaic virus complex. The selected seedling was placed into the field in 1982. As early as 1984, it was recognized for its outstanding qualities including large, relatively firm fruit with glossy medium-red color. Fruit was well displayed and easily removed from the receptacle. The color was more attractive than that of either parent. The flavor was especially appealing. Harvest began in late June and lasted for approximately 6 weeks, up to 2 weeks longer than that of most other cultivars. Such a long season is an especially desirable trait in fresh-market cultivars. The plant was vigorous but did not produce excessive primocanes. Hugh decided to fast-track the selection. Propagation of pathogen-free nuclear stock for production of certified plants began immediately. By 1987 there were plants in growers’ trials, and it was named in 1989, a year before the Plant Royalty Act came into effect in Canada. Thus, unlike the situation with cultivars named since then, it was easy to distribute plants to production regions throughout the world. During the 1990s, favorable performance information was received from the United Kingdom; various western European countries, such as Spain, France, Belgium and the Netherlands; southeastern Australia, and Chile. ‘Tulameen’ canes have relatively low chilling requirement and can be manipulated quite easily and efficiently to flower and fruit out of season or to being forced in greenhouses.

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Hugh’s greatest success, ‘Tulameen’, has become the most widely grown fresh-market cultivar throughout the world. It is the world standard by which other fresh-market and potential fresh-market cultivars are judged. ‘Tulameen’ has been used extensively in breeding programs including those in the private sector. Many millions of new plants are added to growers fields each year. Until 10 years ago, in the Pacific Northwest, ‘Tulameen’ had very little impact on the processing market because ‘Meeker’ was the dominant cultivar. In the last few years, however, cultivar plantings have changed. Significant numbers of Hugh’s raspberry cultivars are now planted in the Pacific Northwest too. In 2007, 28% of the plants sold there were from his program. In the last 7 years, 4.4 million plants of these cultivars were sold in the Pacific Northwest, which is 16.4% of the total plant sales. E. Cultivar Releases ‘Matsqui’ 1961. The origin of this cultivar is a cross between ‘Sumner’ ‘Carnival’. It was released because of its firm, bright-red fruit and relative ease of harvest and resistance to Botrytis fruit rot. This cultivar was never a commercial success but was a good breeding parent for fruit quality, color, and appearance in the New Zealand breeding program. The name is derived from the Halkomelen word meaning ‘‘easy portage’’ or ‘‘easy traveling,’’ referring to the ease of ascending creeks from the Fraser and dragging canoes over the height of land to the old Sumas Lake or to the tributaries of the Nooksack River. ‘Haida’ 1973. The origin of this cultivar is a cross between ‘Malling Promise’  ‘Creston’. This release is particularly winter hardy, probably has resistance to the resistance-breaking strain of RBDV, and is adapted to low-chill conditions and for upright cane growth. The cultivar was named for the Haida people, who live along the coastal bays and inlets of the Queen Charlotte Islands. The tribe is renowned for its carved totem poles and great war canoes. ‘Chilcotin’ 1978. The origin of this cultivar is a cross between ‘Sumner’  ‘Newburgh’. Credited with jump-starting the interest in fresh market in the Pacific Northwest in the early 1980s, ‘Chilcotin’’ is now being grown in niche markets in Ontario and New Zealand. It is a key breeding parent for fresh-market cultivars, giving RBDV resistance and light, nondarkening red color. The name refers to the Chilcotin tribe and country in the Cariboo. It specifically refers to the Chicotin River, which flows east into the Fraser. The name can be translated as

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‘‘ocher river people.’’ ‘‘Ocher’’ here refers not to the color but to the mineral (usually red or yellow) much prized by the First Nations people used as a base for paint or dye. ‘Skeena’ 1977. The origin of this cultivar is a cross between ‘Creston’ SCRI 6010/52, a derivative of ‘Burnetholm’ and ‘Malling Jewel’. Until recent HortResearch releases, ‘Skeena’ was a leading cultivar in New Zealand for the process market. The name is based on the Skeena River, which is derived from two Tsimshian First Nation words meaning ‘‘water out of the clouds.’’ ‘Nootka’ 1978. The origin of this cultivar is a cross between ‘Carnival’ ‘Willamette’. This cultivar is widely recognized as a donor of genes for harvest ease, lower susceptibility to both pre- and postharvest fruit rot, and high soluble solids content as well as some field resistance to root rot and meadow lesion nematode and escape and resistace to RBDV. The name refers to Nootka Sound on the west coast of Vancouver Island. The most likely explanation of the word ‘‘nootka’’ is that the first Europeans to go there heard the First Nations people say noo-kaeh, the imperative of the local verb meaning ‘‘go around.’’ ‘Algonquin’ 1984, 1991. The origin of this cultivar is a cross between ‘Haida’  ‘Canby’. This cultivar was originally released as germplasm for breeding in 1984 under the name BC 72–1–7. It showed potential as a breeding parent as it is homozygous for gene Ag1 , conferring dominant resistance to Amphorophora agathonica, the aphid vector of the raspberry mosaic virus complex. In 1991 it was named and released for its adaptation to conditions in Ontario and in Denmark. ‘Algonquin’ has been a good parent in breeding and has also shown good adaptation to low-chill conditions in New Zealand. The name refers to a group of community of First Nations people in western Ontario and adjacent Quebec, centering on the Ottawa River and its tributaries. The name is appropriate because the cultivar performs particularly well in Ontario and is winter hardy. ‘Chilliwack’ 1987. The origin of this cultivar is a cross between (‘Sumner’  ‘Carnival’)  ‘Skeena’. This high-quality fresh-market raspberry has been the leading cultivar the Santiago region of Chile for transhemispheric air freighting to North America and Europe during November and December for the last 15 years. It is important in the raspberry-growing regions of Victoria, Australia, for the fresh market. It has a relatively high level of root rot tolerance in the field. ‘Chilliwack’

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is very upright and is well adapted to the ‘‘long cane’’ production method for raspberries. The name refers to a local First Nations people and to various geographic features. The Tolkomelen word has the sense of ‘‘quieter waters at the head’’ or ‘‘travel by way of a backwater or slough.’’ The name is particularly appropriate since ‘Chilliwack’ produces firm fruit that travels well. ‘Comox’ 1987. The origin of this cultivar is a cross between BC 64–9–81 (Creston  Willamette)  Skeena. It is a medium-size fruited, highyielding cultivar that has not become a commercial success in its own right. However, it has been a very useful breeding parent for both floricane raspberries (high yield) and primocane fruiting raspberries (lateral structure). The name refers to a Kwakwala First Nation word meaning ‘‘place of plenty’’ with reference to the abundant game and berries in the Comox Valley. The name is appropriate as ‘Comox’ is high yielding. ‘Kitsilano’ 1988. The origin of this cultivar are crosses between ‘Comox’  EM 3909/4; it has a complex origin, with over 4 generations of numbered selections in its origin. This release ripens late in the season and provides an effective overlap with some of the early-ripening primocane cultivars. The medium-size fruit is bright red. This cultivar was superseded at the time of its release by ‘Cascade Delight’ and ‘Coho’, but it has been a great breeding parent, contributing fruit quality and productivity to progenies. The name is derived from the name of Squamish First Nation settler who came from a village on the Squamish River and settled in Stanley Park circa 1860. The cultivar was released with Chaim Kempler. ‘Qualicum’ 1995. The origin of this cultivar is a cross between ‘Glen Moy’  ‘Chilliwack’. This cultivar is grown in British Columbia and transported to eastern North America. The large chunky fruit is extremely firm, well suited for transport; the plant is very vigorous. The name is derived from a Nanaimo First Nations term for ‘‘place of the dog (chum) salmon.’’ ‘Malahat’ 1999. The origin of this cultivar is a cross between ‘Meeker’  BC 7853/116 (SCRI 7269/67  ‘Nootka’). This is the leading early fresh-market cultivar in British Columbia. There is some debate on the origin of this Saanich First Nation name; some say it means ‘‘infested with caterpillars’’ (let us hope not!) and others say it means ‘‘place where one gets bait.’’ This cultivar was released with Chaim Kempler.

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‘Cowichan’ 2005. The origin of this cultivar is a cross between ‘Newburgh’  ‘Qualicum’. This release has shown the most potential in England, where it appears to have resistance to strains of the root rot causal organism. The name is derived from a Halkomelem First Nation word meaning ‘‘warm country’’ or ‘‘warmed by the sun.’’ The name originated because of a large rock formation, on the side of Mount. Tzuhalem, supposedly resembling a frog basking in the sun. This cultivar was released with Chaim Kempler. ‘Esquimalt’ 2005. This cultivar has a complex origin: ‘Comox’  SCRI 7815B8, derived in part from ‘Rumiloba’, ‘Glen Prosen’, ‘Meeker’, ‘Burnetholm’, ‘Malling Jewel’, ‘Malling Exploit’, and others. It is a summer-fruiting, high-yielding plant with large, firm fruit that ripen late and are well suited to fresh market. This cultivar was released with Chaim Kempler. ‘Chemainus’ 2006. The origin of this cultivar is a cross between BC 82– 5–84 (‘Algonquin’  ‘Chilliwack’)]  ‘Tulameen’. It is a recent multipurpose type release being widely planted in the Pacific Northwest. This cultivar was released with Chaim Kempler. ‘Saanich’ 2006. The origin of this cultivar is a cross between BC 82–5– 161 (Algonquin  Chilliwack)  B C 80–28–50 (‘Nootka’  ‘Glen Prosen’. It is a high-yielding newer release suited for machine harvest and a multipurpose type for both fresh and processing markets. This cultivar was released with Chaim Kempler. ‘Nanoose’ 2007. This cultivar has a complex parentage involving ‘Skeena’, ‘Dalhousie Lake 4’, ‘Meeker’, ‘Comox’, and Rubus strigosus. It is a recent release with compact, easily managed growth habit and large, firm fruit. It has genes derived from an entirely new and distinct source of Rubus strigosus, the North American red raspberry. This cultivar was released with Chaim Kempler. F. Current Activities Currently Hugh is an Emeritus Research Scientist with the Pacific Agricultural Research Centre of Agriculture and Agri-Food Canada. He resides in the Point Grey area of Vancouver close to the UBC. Hugh is active in Seeds of Diversity Canada, a nongovernment/nonprofit organization dedicated to the conservation of endangered or rare cultivars of vegetables, fruits, flowers, and grain crops. He regularly writes for the

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magazine and each issue (three per year) he contributes ‘‘News of Diversity’’ with items summarized from the United Nations Food and Agriculture Organisation (FAO) Plant Breeding News, The Garden (from the Royal Horticultural Society), American Society for Horticultural Science publications, newspapers (particularly the Weekly Guardian from the United Kingdom), and various other sources. He completed a term as president of Seeds of Diversity Canada and after 9 years decided it was time to quit the board, although he still writes articles for the organization. He has specialized in articles that highlight the significant of major fruit cultivars: ‘Lloyd George’ raspberry, ‘Willamette’ raspberry, ‘Heritage’ raspberry, ‘Tulameen’ raspberry, ‘Cox’s Orange Pippin’ apple, ‘Granny Smith’ apple, and ‘Senga Sengana’ strawberry. He is an active Friend of the Garden at the University of British Columbia (UBC) Botanical Garden and is currently a member of the executive committee and program chair. He purchases native plants from specialty wholesale nurseries and does some propagation for the annual perennial and native plant sale and for the popular Plant Centre. He also has permission to propagate ‘Totem’ strawberry and ‘Tulameen’ raspberry for sale at the Botanical Garden Centre. He is active in the Native Plant Society of British Columbia and is currently on its board. He regularly writes article for their thrice-yearly publication Menziesia. He also writes for the Cider Press, a publication of the nonprofessional BC Fruit Testers Association, and occasionally for Davidsonia, a publication of the UBC Botanical Garden, and GardenWise, a local gardening magazine. Hugh and Marian have been active hikers and twice trekked in the Himalayas, the first time in the mountains in the North India in August when the alpine flora is at its peak and the second time in East India (Sikkim in April), primarily to look at rhododendrons. The second trek was marred, by eye problems for Hugh—a detached retina in an isolated site at a high altitude (about 4000m). His eye was badly damaged, and he could not receive medical attention until he returned to Vancouver 10 days later. Since then he has suffered a series of eye problems. Hugh was an avid runner and did several marathons. He now has begun power walking with poles, an activity that gives great confidence to sight-impaired persons. He also does water exercises on a regular basis. He still is an enthusiastic gardener in Vancouver and at his cottage at Reider Lake. Hugh and Marian have three grown children. Son Peter is a consulting geologist, currently working in Saskatchewan. Older daughter Jennifer is with Foreign Affairs in Ottawa and director of Canadian trade in Near Eastern and African countries. Younger

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daughter Carolyn is a therapist at a clinic on the UBC campus. She is also a part-time track and field coach and travels both nationally and internationally as part of the support group of teams competing in various events. Jennifer and her husband, Dave, have two sons, Alex and Eric, whom the grandparents visit as much as possible. G. Awards and Honors Hugh is a fellow of the American Society for Horticultural Science (ASHS) and was president of the American Pomological Society (APS) in 1978–1979. He is recipient of the Wilder Medal (1986) from the APS. He received outstanding cultivar awards for ‘Totem’ from the Canadian Society for Horticultural Science (CSHS), and for ‘Tulameen’ from both the CSHS and ASHS. In 1994 he received an honorary D.Sc. from MacDonald College of McGill University, Montreal. Hugh has published more than 90 reviewed papers and several book chapters. He has innumerable miscellaneous papers and bulletins to his credit and has presented more than 500 reports to industry meetings over the years. He has spoken to industry groups in Australia, Chile, Argentina, Washington State, Oregon, Ontario, as well as locally. He participated in a program review in New Zealand and assisted in establishing a successful raspberry breeding program in Victoria, Australia. He was on the editorial board of the Canadian Journal of Plant Science for six years and editor of 2 volumes of Acta Horticulturae, based on Rubus/ Ribes symposia in 1980 and 1989, respectively. He was assigned to Agricultural Canada’s Expert Committee on Gene Resources for 6 years. This important post lead to his invitation to serve as executive and President of Seeds of Diversity of Canada, where he served for 9 years. Hugh has been involved as a contributing author for the New Fruit and Nut Varieties list for raspberries and strawberries, since 1970. He became the author for the raspberries section from 1991 to present and in strawberries from 1994. For List 38, published in 1997, he prepared descriptions of blackberry and hybrid berries, currant, gooseberry, and strawberry as well as raspberry. He continues to prepare descriptions of raspberry cultivars for the HortScience listings. Hugh has twice been chair of the Rubus-Ribes Working Group of the International Society for Horticultural Science and, as such, successfully organized 2 of the Group’s symposia. For many years he was a director of the Lower Mainland Horticultural Improvement Association. For more than 30 years he presented talks at their annual meetings. He also participated in similar growers’ organizations in Washington and Oregon, and was invited to talk to groups in Ontario

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several times and to the North American Strawberry Growers Association and the North American Bramble Growers Association. Hugh Daubeny, berry geneticist and breeder, collaborator, and friend, has had a distinguished career. He continues to motivate and educate the scientific community. His compassion for the environment and acute awareness of the need to conserve wild genetic resources provides a direct lesson for our time. He has brought us great riches in the form of his cultivars, which have become classic standards for raspberries and strawberries. His life and work is an inspiration for us now and for the future. IV. SELECTED PUBLICATIONS OF HUGH A. DAUBENY A. Journal Articles Barritt, B. H., and H. A. Daubeny. 1982. Inheritance of virus tolerance in strawberry. J. Am. Soc. Hort. Sci. 107:278–282. Baumann, T. E., and H. A. Daubeny. 1989. Evaluation of the waiting-bed cultural system for strawberry season extension in British Columbia. Adv. Strawberry Prod. 8:55–57. Bristow, P. R., H. A. Daubeny, T. M. Sjulin, H. S. Pepin, R. Nestby, and G. E. Windom. 1988. Evaluation of Rubus germplasm for reaction to root rot caused by Phytophthora erythroseptica. J. Am. Soc. Hort. Sci. 113:588–591. Buonassisi, A. J., H. A. Daubeny, and B. Peters. 1989. The B.C. Raspberry certification program. Acta Hort. 262:175–180. Cousineau, J. C., A. K. Anderson, and H. A. Daubeny. 1993. Characterization of red raspberry cultivars and selections using isoenzyme analysis. HortScience 28:1185– 1186. Cram, W. T., and H. A. Daubeny. 1982. Responses of black vine weevil adults fed foliage from genotypes of strawberry, red raspberry, and red raspberry-blackberry hybrids. HortScience 17:771–773. Dale, A., and H. A. Daubeny. 1985. Genotype-environment interactions involving British and Pacific Northwest red raspberry cultivars. HortScience 20:68–69. Dale, A., and H. A. Daubeny. 1987. Flower-bud initiation in red raspberry (Rubus idaeus L.) in two environments. Crop. Res. (Hort. Res.) 27:61–66. Daubeny, H. A. 1961a. Earliness in tomato varieties with special reference to the ability to set fruit at low temperatures. Proc. Am. Soc. Hort. Sci. 78:445–449. Daubeny, H. A. 1961b. Powdery mildew resistance in strawberry progenies. Can. J. Plant. Sci. 41:239–243. Daubeny, H. A. 1964. Effect of parentage in breeding for red stele resistance of strawberry in British Columbia. Proc. Am. Soc. Hort. Sci. 84:289–294. Daubeny, H. A. 1966. Inheritance of immunity in the red raspberry to the North American strain of the aphid. Amphorophora rubi Kltb. Proc. Am. Soc. Hort. Sci. 88:346–351. Daubeny, H. A. 1971. Self-fertility in red raspberry cultivars and selections. J. Am. Soc. Hort. Sci. 96:588–591. Daubeny, H. A. 1972. Screening red raspberry cultivars and selections for immunity to Amphorophora agathonica. HortScience 7:265–266.

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Daubeny, H. A. 1978. Red raspberry cultivars for the Pacific Northwest. Fruit Var. J. 32:89–93. Daubeny, H. A. 1980. Red raspberry cultivar development in British Columbia with special reference to pest response and germplasm exploitation. Acta Hort. 112:59–67. Daubeny, H. A. 1983a. Expansion of genetic resources available to red raspberry breeding programs. Proc. 21st. Int. Hort. Congr. 1:150–155. Daubeny, H. A. 1983b. Red raspberry breeding in British Columbia. HortScience 18:268. Daubeny, H. A. 1986. The British Columbia raspberry breeding program since 1980. Acta Hort. 183:47–58. Daubeny, H. A. 1987. A hypothesis for inheritance of resistance to cane Botrytis in red raspberry. HortScience 22:116–119. Daubeny, H. A. 1990 Strawberry breeding in Canada. HortScience 25:893–894. Daubeny, H. A. 1995. Sustained funding support needed for fruit breeding programs. Heritage Seed Program 8:26–30. Daubeny, H. A. 1997. Raspberry breeding in Canada: 1920 to 1995. Fruit Var. J. 51:228–233. Daubeny, H. A. 2002. Raspberry breeding in the 21st century. Acta Hort. 585:69–72. Daubeny, H. A. 2003a. British Columbia’s Pacific Coast beach strawberry—Fragaria chiloensis. Davidsonia 14:5–11. Daubeny, H. A. 2003b. The North American red raspberry—a genetic resource awaiting exploitation. Davidsonia 14:145–151. Daubeny, H. A. 2006. History of the British Columbia raspberry breeding programme. Davidsonia 17:9–21. Daubeny, H. A., and A. K. Anderson. 1989. Germplasm enhancement in the British Columbia raspberry breeding program. Acta Hort. 262:61–64. Daubeny, H. A., and A. K. Anderson. 1993. Achievements and prospects: The British Columbia red raspberry breeding program. Acta Hort. 352:285–293. Daubeny, H. A., P. C. Crandall, and G. W. Eaton. 1967. Crumbliness in red raspberry with special reference to the ‘Sumner’ variety. J. Am. Soc. Hort. Sci. 91:224–230. Daubeny, H. A., A. Dale, and G. R. McGregor. 1986. Estimating yields of red raspberries in small research plots. HortScience 21:1216–1217. Daubeny, H. A., and C. D. Fear. 1992. Primocane fruiting raspberries in the Pacific Northwest and California. Fruit Var. J. 46:197–199. Daubeny, H. A., J. A. Freeman, and H. S. Pepin. 1974. Two techniques for assessing preharvest fungicide treatments on postharvest fruit rot of red raspberry. Plant Dis. Reptr. 58:391–395. Daubeny, H. A., J. A. Freeman, and R. Stace-Smith. 1970. Effects of virus infection on drupelet set of four red raspberry cultivars. J. Am. Soc. Hort. Sci. 95:730–731. Daubeny, H. A., J. A. Freeman, and R. Stace-Smith. 1975. Effects of tomato ringspot virus on drupelet set of red raspberry cultivars. Can. J. Plant. Sci. 55:755–759. Daubeny, H. A., J. A. Freeman, and R. Stace-Smith. 1982. Effects of raspberry bushy dwarf virus on yield and cane growth in susceptible red raspberry cultivars. HortScience 17:645–647. Daubeny, H. A., R. A. Norton, C. D. Schwartz, and B. H. Barritt. 1970b. Winterhardiness in strawberries for the Pacific Northwest. HortScience 5:152–154. Daubeny, H. A., and H. S. Pepin. 1965. The relative resistance of various Fragaria chiloensis clones to Phytophthora fragariae. Can. J. Plant. Sci. 45:365–368. Daubeny, H. A., and H. S. Pepin. 1969. Variations in susceptibility to fruit rot among red raspberry cultivars. Plant Dis. Reptr. 53:975–977. Daubeny, H. A., and H. S. Pepin. 1974a. Susceptibility variations to spur blight (Didymella applanata) among red raspberry cultivars and selections. Plant Dis. Reptr. 58: 1024–1027.

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Daubeny, H. A., and H. S. Pepin. 1974b. Variations among red raspberry cultivars and selections in susceptibility to the fruit rot causal organisms Botrytis cinerea and Rhizopus spp. Can. J. Plant. Sci. 54:511–516. Daubeny, H. A., and H. S. Pepin. 1975a. Assessment of some red raspberry cultivars and selections as parents for resistance to spur blight. HortScience 10:404–405. Daubeny, H. A., and H. S. Pepin. 1975b. Fruit rot resistance in red raspberry. Fruit Var. J. 29:21. Daubeny, H. A., and H. S. Pepin. 1976. Recent developments in breeding for fruit rot resistance in red raspberry. Acta Hort. 60:63–72. Daubeny, H. A., and H. S. Pepin. 1977. Evaluation of strawberry clones for fruit rot resistance. J. Am. Soc. Hort. Sci. 102:431–435. Daubeny, H. A., and H. S. Pepin. 1981. Resistance of red raspberry fruit and canes to Botrytis. J. Am. Soc. Hort. Sci. 106:423–426. Daubeny, H. A., H. S. Pepin, and B. H. Barritt. 1980. Postharvest Rhizopus fruit rot resistance in red raspberry. HortScience 15:35–37. Daubeny, H. A., and R. Stace-Smith. 1963. Note on immunity to the North American strain of the red raspberry mosaic vector, the aphid, Amphorophora rubi. Kalb. Can. J. Plant. Sci. 43:413–414. Daubeny, H. A., R. Stace-Smith, and J. A. Freeman. 1978. The occurrence and some effects of raspberry bushy dwarf virus in red raspberry. J. Am. Soc. Hort. Sci. 103:519–522. Daubeny, H.A., and D. Stary. 1982. Identification of resistance to Amphorophora agathonica in the native North American red raspberry. J. Am. Soc. Hort. Sci. 107:593–597. Daubeny, H. A., P. B. Topham, and D. L. Jennings. 1968. A comparison of methods for analyzing inheritance data for resistance to red raspberry powdery mildew. Can. J. Genet. Cytol. 10:341–350. Donnelly, D. J., and H. A. Daubeny. 1986. Tissue culture of Rubus species. Acta Hort. 183:305–314. Donnelly, D. J., F. E. Skelton, and H. A. Daubeny. 1986. External leaf features of tissuecultured ‘Silvan’ blackberry. HortScience 21:306–308. Freeman, J. A., and H. A. Daubeny. 1986. Effect of chemical removal of primocanes on several raspberry cultivars. Acta Hort. 183:215–222. Freeman, J. A., G. W. Eaton, T. E. Baumann, and H. A. Daubeny. 1989. Primocane removal enhances yield components of raspberries. J. Am. Soc. Hort. Sci. 114:6–9. Freeman, J. R., V. R. Brookes, and H. A. Daubeny. 1989. Effect of continual primocane removal on several raspberry cultivars. Acta Hort. 262:341–348. Hall, H. K., and H. A. Daubeny. 1999. Introduced germplasm in the New Zealand raspberry industry and breeding programme. Acta Hort. 505:59–63. Hoover, E. E., J. J. Luby, D. S. Bedford, M. P. Pritts, E. J. Hanson, A. Dale, and H. A. Daubeny. 1989. Temperature influence on harvest date and cane development of primocane-fruiting red raspberries. Acta Hort. 626:297–303. John, M. K., and H. A. Daubeny. 1972. Influence of genotype, date of sampling and age of plant on leaf chemical composition of red raspberry (Rubus idaeus L.). J. Am. Soc. Hort. Sci. 97:740–742. John, M. K., H. A. Daubeny, and F. D. McElroy. 1975. Influence of sampling time on elemental composition of strawberry leaves and petioles. J. Am. Soc. Hort. Sci. 100:513– 517. Kempler, C., and H. A. Daubeny. 1999. Development of fresh market raspberry cultivars. Acta Hort. 505:121–126. Levesque, C. A., and H. A. Daubeny. 1999. Variation in reaction to Phytophthora fragariae var. Rubi in raspberry genotypes. Acta Hort. 505:231–235.

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Misˇic´, P. D., Z. V. Tesovic, H. A. Daubeny, and H. S. Pepin. 1975. Relative resistance to spur blight (Didymella applanata) among red, purple and black raspberry cultivars and selections in Yugoslavia. Plant Dis. Reptr. 59:571–573. Moore, P. P., and H. A. Daubeny. 1993. ‘Meeker’ red raspberry. Fruit Var. J. 47:2–4. Parliman, B. J., and H. A. Daubeny. 1988. Considerations for effective exchange of clonally propagated plant germplasm. HortScience 23:67–73. Shamaila, M., B. Skukra, H. A. Daubeny, and A. K. Anderson. 1993. Sensory, chemical and gas chromatographic evaluation of five raspberry cultivars. Food Res. Int. 26:443–449. Stace-Smith, R., H. A. Daubeny, P. R. Bristow, and G. Baumann. 1982. Incidence of sap transmitted viruses in experimental and commercial plantings of red raspberries. Acta Hort. 129:91–101. Vrain, T. C., and H. A. Daubeny. 1986. Relative resistance of red raspberry and related genotypes to the root lesion nematode. HortScience 21:1435–1437. Vrain, T. C., H. A. Daubeny, J. W. Hall, R. M. DeYoung, and A. K. Anderson. 1994. Inheritance of resistance to root lesion nematode in red raspberry. HortScience 29:1340– 1341.

B. Book Chapters Crandall, P. C., and H. A. Daubeny. 1990. Raspberry management. pp. 157–213. In: G. J. Galletta and D. G. Himelrick (eds.), Small fruit crop management. Prentice-Hall, Englewood Cliffs, NJ. Daubeny, H. A. 1983. Insect, mite and nematode resistance. pp. 216–241. In: J. N. Moore and J. Janick (eds.), Methods in fruit breeding. Purdue Univ. Press, West Lafayette, IN. Daubeny, H. A. 1996. Brambles. pp. 109–190. In: J. Janick and J. N. Moore (eds.), Fruit breeding: Vol. II. Vine and small fruit crops. Wiley, New York. Daubeny, H. A., and A. K. Anderson. 1991. Strawberry breeding in British Columbia. In: A. Dale and J. J. Luby (eds.), The strawberry into the 21st century. Timberline Press, Portland, OR. Jennings, D. L., H. A. Daubeny, and J. N. Moore. 1991. Blackberries and raspberries (Rubus). In: Genetic resources of temperate fruit and nut crops. Acta Hort. 290:331–389. Khanizadeh, S., H. A. Daubeny, and J. A. Sullivan. 2005. Canadian strawberry breeders. pp. 14–22. In: S. Khanizadeh and J. De Ell (eds.), Our strawberries/les fraisiers de chez nous. Publishing and Depository Services, Ottawa, Ontario.

C. Cultivar Release Notices Daubeny, H. A. 1969. Matsqui red raspberry. Can. J. Plant. Sci. 49:227. Daubeny, H. A. 1973. Haida red raspberry. Can. J. Plant. Sci. 53:345–346. Daubeny, H. A. 1978a. Chilcotin red raspberry. Can. J. Plant. Sci. 58:279–282. Daubeny, H. A. 1978b. Nootka red raspberry. Can. J. Plant. Sci. 58:899–901. Daubeny, H. A. 1978c. Skeena red raspberry. Can. J. Plant. Sci. 58:565–568. Daubeny, H. A. 1987a. ‘Chilliwack’ and ‘Comox’ red raspberries. HortScience 22:1343– 1345. Daubeny, H. A. 1987b. ‘Sumas’ strawberry. HortScience 22:511–513. Daubeny, H. A., and A. K. Anderson. 1991. ‘Tulameen’ red raspberry. HortScience 26:1336–1338. Daubeny, H. A., A. Dale, P. P. Moore, A. R. Jamieson, O. Callesen, and H. K. Hall. 1991. Algonquin red raspberry. Fruit Var. J. 45:122–124.

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Daubeny, H. A., and C. Kempler. 1995. ‘Qualicum’ red raspberry. HortScience 30:1470– 1472. Daubeny, H. A., and C. Kempler. 1997. ‘Nanaimo’ strawberry. HortScience 32:1293–1294. Daubeny, H. A., and C. Kempler. 2003. ‘Tulameen’ red raspberry. Journal of the American Pomological Society 57:42. Daubeny, H. A., F. J. Lawrence, and P. P. Moore. 1993. ‘Totem’ strawberry. Fruit Var. J. 47:182–184. Daubeny, H. A., and T. M. Sjulin. 1984. BC 72–1–7 red raspberry. HortScience 19:733–734. Kempler, C., and H. A. Daubeny. 2000. ‘Malahat’ red raspberry. HortScience 35:783–785. Kempler, C., H. A. Daubeny, L. Frey, and T. Walters. 2006. ‘Chemainus’ red raspberry. HortScience 41:1364–1366. Kempler, C., H. A. Daubeny, B. Harding, T. Baumann, C. E. Finn, P. P. Moore, M. Sweeney, and T. Walters. 2007. ‘Saanich’ red raspberry. HortScience 42:176–178. Kempler, C., H. A. Daubeny, B. Harding, and C. E. Finn. 2005. ‘Esquimalt’ red raspberry. HortScience 40:2192–2194. Kempler, C., H. A. Daubeny, B. Harding, and C. G. Kowalenko. 2005. ‘Cowichan’ red raspberry. HortScience 40:1916–1918. Moore, P. P., T. M. Sjulin, B. H. Barritt, and H. A. Daubeny. 1990. ‘Centennial’ red raspberry. HortScience 25:484–485. (Pat Moore cultivar release, Hugh Daubeny collaborator.)

2 Raspberry Breeding and Genetics Harvey K. Hall Shekinah Berries Ltd 1 Clay Street Motueka 7120, New Zealand Kim E. Hummer USDA-ARS Clonal Germplasm Repository 33447 Peoria Road Corvallis, Oregon, 97330-2521 USA Andrew R. Jamieson Fruit Breeding Agriculture and Agri-Food Canada 32 Main Street Kentville, Nova Scotia, B4N 1J5 Canada S. Nikki Jennings Mylnefield Research Services Ltd. Scottish Crop Research Institute Invergowrie, Dundee, DD2 5DA Scotland Courtney A. Weber Department of Horticultural Sciences Cornell University New York State Agricultural Experiment Station Geneva, NY 14456 USA

Plant Breeding Reviews, Volume 32 Edited by Jules Janick Copyright & 2009 John Wiley & Sons, Inc. 39

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CONTENTS I. INTRODUCTION, 45 A. Preface, 50 B. Origin and Speciation, 51 1. Dispersal 2. Environmental Adaptation 3. Diversity 4. Traditional Uses from the Wild C. History of Improvement, 59 1. Domestication 2. Floricane Fruiting 3. Primocane Fruiting D. World Industry, 66 1. North America 2. Australasia 3. China and East Asia 4. Russian Federation and the Ukraine 5. Europe 6. Eastern Europe 7. Southern Europe 8. Africa 9. South America E. Uses, 72 F. Breeding Objectives, 73 II. GERMPLASM RESOURCES, EXPLORATION, AND MAINTENANCE, 75 A. Acquisition of New Germplasm, 73 B. Value of Clonal Germplasm versus Seed, 79 C. Germplasm Preservation, 81 D. Pathogens and Safe International Plant Movement, 85 E. Germplasm Assessment and Publication of Data, 89 F. Germplasm Needs as Delineated by Traits, 89 III. BREEDING TECHNOLOGY, 90 A. Floral Biology, 90 B. Hybridization, 92 C. Seed Extraction and Storage, 94 D. Seed Treatment and Germination, 95 E. Seedling Evaluation, 97 F. Selection Evaluation, 102 G. Privatization, Plant Patent/PVR Descriptions and Strategies, 108 H. Cultivar Release and Commercialization, 115 I. Propagation, 116 1. Suckers, Canes, and Transplants 2. Roots 3. Root Cuttings and Other Traditional Methods 4. Shoot Cuttings 5. In Vitro 6. High-Health Stock and Trueness to Type 7. Genetic Stability

2. RASPBERRY BREEDING AND GENETICS J. Molecular Techniques, 126 1. Diversity and Taxonomy 2. Cultivar Identification 3. Inheritance and Genetic Mapping 4. Genetic Transformation IV. BREEDING SYSTEMS, 135 A. Genetic Structure, 135 B. Breeding Strategy, 137 C. Response to Selection, 143 D. Interspecific Hybridization, 146 E. Inheritance Patterns, 152 V. BREEDING FOR SPECIFIC CHARACTERS, 153 A. Adaptation, 153 1. Cold-hardiness 2. Cool Conditions 3. Low-Chill Climates and Hot Conditions 4. Greenhouses and Tunnels 5. Other Adverse Environmental Conditions B. Diseases and Pests, 184 C. Resistance to Fungal Diseases, 186 D. Fungal Diseases Attacking Roots, 187 1. Phytophthora Root Rot 2. Other Phytophthora Species 3. Verticillium Wilt 4. Other Root Diseases E. Fruit Rots, 196 1. Botrytis Fruit Rot 2. Minor Fruit Rots F. Cane and Leaf Diseases, 202 1. Spur Blight 2. Cane Blight 3. Fusarium Wilt 4. Anthracnose or Cane Spot 5. Cane Botrytis 6. Raspberry Leaf Spot 7. Powdery Mildew 8. Ascospora Dieback 9. Sydowiella and Gnomonia Cane Cankers 10. Nectria Canker 11. Silver Leaf 12. Rosette or Double Blossom 13. Downy Mildew 14. Yellow Rust 15. Late Leaf Rust 16. Orange Rust 17. Cane and Leaf Rust G. Resistance to Bacterial Diseases, 219 1. Crown Gall 2. Fire Blight

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H.

I.

J.

K.

3. Pseudomonas Blight 4. Other Bacterial Diseases Resistance to Pests, 221 1. Aphids 2. Cane Midge 3. Raspberry Beetle and Raspberry Fruitworm 4. Cantharid Beetle 5. Weevils 6. Nematodes 7. Mites 8. Raspberry Moth 9. Raspberry Cane Borer 10. Raspberry Bud Moth 11. Grass Grub 12. Double Dart Moth Resistance to Virus Diseases, 242 1. Pollen and Seed Transmitted Viruses 2. Aphid-Transmitted Viruses 3. Nematode-Transmitted Viruses 4. Viruslike Diseases Plant Growth, 247 1. Roots 2. Cane Number 3. Cane Growth 4. Spinelessness 5. Bud Break 6. Lateral Structure 7. Fruit Numbers per Lateral/Fruiting Node 8. Yield Components 9. Total Yield 10. Leaves 11. Primocane Fruiting Fruit Quality, 275 1. Structure 2. Skin Strength 3. Fruit Texture 4. Coherence 5. Flavor 6. Fresh-Market Flavor 7. Processing Flavor 8. Aroma 9. Sugar Content 10. Acidity 11. Seediness 12. Appearance 13. Color 14. Shelf Life 15. Ability to Be Transported 16. Shape 17. Fruit Size

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18. Pests and Disease 19. Environmental Concerns 20. Suitability for Different Uses 21. Nutritional and Pharmochemical Content L. Machine Harvesting, 298 VI. ACHIEVEMENTS AND PROSPECTS, 309 ACKNOWLEDGMENTS LITERATURE CITED

ABBREVIATIONS AFLP Amplified fragment length polymorphism CU-NYSAES Cornell University, New York State Agricultural Experiment Station, Geneva, New York DSA Driscoll Strawberry Associates, at Watsonville, California EC European Economic Community ELISA Enzyme-linked immunosorbent assay EMR East Malling Research (Horticulture Research International East Malling from 1991 and prior to that East Malling Research Station) at East Malling, Kent, England GRIN United States Department of Agriculture, Germplasm Resources Information Network HRNZ Horticulture and Food Research Institute of New Zealand Ltd, HortResearch, Riwaka, New Zealand IPM Integrated pest management IQF Individually quick frozen ISSR Inter simple sequence repeats MAS Marker-assisted selection MRL Maximum residue level ORUS Oregon State University—United States Department of Agriculture at Corvallis, Oregon PARC-BC Agriculture and Agri-Food Canada’s (AAFC’s), Pacific Agri-Food Research Centre, British Columbia RACER Reduced application of chemicals in European raspberry production RAPD Random amplified polymorphic DNA RBDV Raspberry bushy dwarf virus RB-RBDV Resistance breaking strain of Raspberry bushy dwarf virus SCRI Scottish Crop Research Institute, Dundee, Scotland SSR Simple sequence repeats WSU Washington State University, Puyallup, Washington

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Raspis The Raspis is called in Greeke Ba´toB ı´daa: in Latine Rubus Idaus, of the mountaine Ida on which it groweth: in English Raspis, Framboise, and Hindberry *The temperature and vertues. The young buds or tender tops of the Bramble Bush, the flowers, the leaves, and the unripe fruit, do very much dry and binde withal: being chewed they take away the heate and inflammation of the mouth, and almonds of the throte; they stay the bloudy flix, and other fluxes, and all maner of bleedings; of the same force is their decoction, with a little honie added. They heale the eyes that hang out; hard knots in the fundamen; and staie the hermorrhoids, if the leaves be laid thereunto. The iuice which is pressed out of the stalkes leaves, and unripe berrie, and made hard in the sun, is more effectual for all those things. The ripe fruit is sweete, and containeth in it much iuice of a temperate heate, therefore it is not unpleasant to be eaten. It hath also a certaine kinde of astriction or binding qualitie. It is likewise for that cause holsome for the stomake; and if a man eate too largely therof, saith Galen, he shall have the headach: but being dried whilest it is yet unripe, it bindeth and drieth more than the ripe fruit. The roote besides that it is binding, containeth in it much thin substance, by reason whereof it wasteth awai the stones in the kidneies, saith Galen. Plinie writeth, that the berries and flowers do provoke urine, and that the decoction of them in wine, is a present remedie against the stone. The leaves of the Bramble, boiled in water, with honie, alum, and a little white wine added thereto, make a most excellent lotion or washing water, to heale the sores in the mouth, the privie parts of man or woman; and the same decoction fastneth the teeth. The Raspis is thought to be like the Bramble, in temperature and vertues, but not so much binding or drying. The Raspis, saith Dioscorides, performeth those things which the Bramble doth. The fruit is good to be given to those that have weake and queasie stomacks. Gerard 1597

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I. INTRODUCTION The earliest records of raspberry in western civilization date to the ancient Greeks (Hummer and Janick 2007). Brambles were documented in the writings of Aeschylus (Hendrickson 1981) and Hippocrates, between 500 to 400 BCE. Raspberries were cultivated by the Greeks as early as 370 BCE (Handley and Pritts 1989). Marcus Porcius Cato (234– 149 BCE), known as Cato the Elder, refers to brambles as weeds to be pulled (spinas runcari) in his work De Re Rustica (De Agricultura) (Hooper and Ash 1934). Publius Ovidius Naso, known as Ovid (43 BCE–17 CE) also mentions wild brambles in Metamorphosis (Miller 1999). Pedanius Dioscorides described the medical uses of raspberries, Batos idaea, in his De Materia Medica, ca. 50 CE (Anicia 512). He also described thornless types. Up to this time Rubus was known for medicinal purposes. About 65 BCE, Pompey introduced raspberries from southeast Troy, now Turkey, to Rome (Trager 1995). Rutilius Taurus Aemilianus Palladius, a Roman writer of the fourth century CE, provided the earliest remaining account of raspberry domestication (Graham et al. 2007; Jennings 1988). Raspberry seeds, dating to Roman times, were discovered in Roman forts in Britain, so most likely Roman soldiers spread the cultivation of this plant throughout Europe. In Russia raspberries were consumed in a decoction with bilberry prior to the establishment of Moscow in 1147 (Zhukovskii 1950). Red raspberries were popularized and selected in Europe throughout the Middle Ages. Europeans were not the only ones to recognize medicinal values in raspberries. Asian raspberries, specifically Rubus chingii Hu, fupen-tzu, fruit was documented in the Ming I pieh lu, a Chinese herbal dating to the end of the Liang Dynasty before 300 CE (Hsu et al. 1986). This fruit was used for impotence, involuntary emission, enuresis, urinary frequency, and dizziness. Another Asian raspberry, Rubus parvifolius L., Tzu-po, is a traditional folk medicine of Taiwan (Hsu et al. 1986) and is used to reduce fever, rheumatoid arthritis, functional bleeding, edema, external and internal trauma, and toxic swelling, among other benefits. In Europe, yellow-fruited forms, a color mutant of the common redfruited R. idaeus L. subsp. vulgatus Arrh. (hereafter referred to as R. idaeus), were documented by the late 1500s. John Parkinson described red, white, and thornless raspis-berries suitable for the English climate (Jennings 1988). Raspberries were grown for the London market by gardeners of Chiswick and Brentford in the time of

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Fig. 1. Woodcut of raspberry from Gerard’s herbal of 1633.

Shakespeare (Jennings 1988). Richard Weston mentioned a ‘‘twicebearing kind’’ in 1780 (Jennings 1988). In old English, raspberries (Fig. 1) were known as hyndberries, raspis, or raspes, giving rise to the modern term raspberry. In German, raspberries are known as himbeeren; in Denmark, as bringebær; in

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Sweden, as hallon; in Italy, as lampone; in France, as framboise; in the Netherlands, as framboos; in Spanish, as frambuesa; and in eastern European languages, as malina. Raspberries were exported to the American colonies in the 1700s (Graham et al. 2007). Probably one or more selections of the American red raspberry, R. idaeus L. subsp. strigosus Michx (hereafter referred to as R. strigosus) were cultivated in America by 1800 (Darrow 1937). In 1771 W. Prince was the first to sell raspberry plants commercially in New York. His son, W. R. Prince, published a pomological manual in 1832 with descriptions of 20 cultivars (Jennings 1988). The American Pomological Society recommended 4 European red raspberries in 1853 and 14 European and 6 American cultivars by 1891 (Hedrick 1925). The European raspberries proved less adapted than the local forms to the extremes of summer and winter weather of America. Great improvements in red raspberry occurred when European red raspberries, R. idaeus, were crossed with American red raspberries, R. strigosus (Jennings 1988). The American subspecies differs from European R. idaeus by having hardier canes, which are thinner, taller, and more erect. Fruit are usually round and seldom conical like R. idaeus, and in the wild fruit sometimes are larger than the European subspecies (Jennings 1988). The cultivar ‘Cuthbert’, most likely a cross between R. idaeus ‘Hudson River Antwerp’ and a native R. strigosus, was discovered about 1865 and remains as a valuable cultivar and source of useful traits to the present (Plate 2B). ‘Lloyd George,’ a cultivar selected from a wood in Dorsett or Kent in the United Kingdom in 1919 (Knight et al. 1972; Leemans and Nannenga 1957) and introduced into the United States from Puyallup, Washington, in 1943, became a very successful parent and was widely used by raspberry breeders for decades (Plate 2C). ‘Lloyd George’ was a very useful source of fruit quality, yield, and the primocane fruiting trait and a source of resistance to the North American aphid, Amphorophora agathonica Hottes, the vector of the raspberry mosaic virus (Daubeny and Stary 1982; Huber and Schwartze 1938; Schwartze and Huber 1937). The widespread use of ‘Lloyd George’ for breeding both primocane fruiting and floricane fruiting cultivars of raspberries and the use of a very limited range of other cultivars as a source of founding clones for raspberry breeding has enabled accelerated progress in terms of fixing some traits. However, it has also undermined the future of raspberry breeding by creating a bottleneck through reducing diversity and increasing the amount of inbreeding in the gene pool. By 1992 an assessment of the genetic base of modern raspberries showed that they were descended from as few as 25 founding clones, or

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likely less if some of these clones prove to be closely related, as is likely from their origin (Dale et al. 1993). Domestication has clearly reduced genetic and morphological diversity in red raspberry, with modern cultivars being genetically very similar (Gordon et al. 2005). Restricted genetic diversity is of serious concern for future Rubus breeding, especially when seeking durable resistance to aggressive pests and diseases for which the repeated use of pesticides is ineffective, unsustainable, or unacceptable in some markets, especially for ‘‘organic production’’ (Gordon et al. 2005). Incorporation of durable resistances to pests and diseases is essential for the development of cultivars suitable for production under integrated pest management (IPM) systems. Some efforts have been expended in breeding to increase the number of founding clones in new cultivars, but future breeders still must keep this bottleneck in mind. Raspberry growing and production, especially for fresh-market sales, has expanded considerably in recent years. The range of adaptation for raspberries has been increased considerably from the natural range of wild raspberries, into regions with hotter summer temperatures, higher humidity, lower chill, and/or subject to pests and diseases that would devastate the crop without a routine spray program. Some of this expansion has been made possible by the development of new cultivars utilizing adaptive traits from wild species. Other advances into new production zones have been made possible by changes in cultural methods, the use of long cane production through transportation of canes from cool climate nurseries, and through the use of cold stores to give artificial chill. Examples of cultivars with adaptive traits for these characters include ‘Autumn Bliss’, ‘Chilliwack’, and DSA cultivars, especially ‘Joe Mello’ and ‘Isabel’, ‘Glen Ample’, ‘Glen Lyon’, ‘Joan Squire’, ‘Motueka’, ‘Moutere’, ‘Tadmor’ and ‘Tulameen’. Fruit quality for fresh-market cultivars also has improved greatly, allowing earlier picking to be done and fruit to be transported long distances to markets. New technology has resulted in the development of see-through clamshell or sealed containers (Fig. 2) so that fruit can be more easily handled during shipment, storage, and at the point of sale. Efficient handling protocols have been developed to quickly transport harvested fruit to a cool store for removal of field heat and for transportation to the point of sale, to maintain the cool chain throughout the handling process. Fruit firmness and skin strength have been improved to reduce handling damage, and cultivars have been developed that are less susceptible to fruit rots in the field or after harvest, allowing long shelf life in storage. Another significant advance in fruit quality has been the selection of cultivars that remain a light, bright red

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Fig. 2. Clear clamshell for raspberry fresh marketing. (photo by Driscoll’s).

color during storage, giving the appearance of freshness throughout their storage life. Raspberries developed for fresh markets have reduced acidity, greater sweetness, and a fresh, light flavor that is sensed on the tip of the tongue, rather than well back in the mouth, as with the strongflavored processing types. Significant advances for processing cultivars in recent years have been the development of machines for harvesting high-quality fruit and improved equipment for producing an individually quick frozen (IQF) product (Fig. 3) with most of the production of a machine harvest cultivar. Mechanical harvesting, principally in the Pacific Northwest of North America, has expanded significantly, but in recent years hand harvest production of process raspberries has expanded in Chile, Serbia, and Poland. Cheap labor is used to compete with the machine-harvested product from developed nations, and hand harvest production is also likely to rise in China. Process production in Scotland has diminished partly due to competition from eastern Europe (Jennings et. al. 2008). However, demand from multiple retailers for fresh raspberries has led to a shift in production toward the fresh market and protected cropping, which now accounts for approximately 80% of Scottish raspberry production. As the fresh raspberry industry has expanded, breeding of new cultivars, marketing, and production has shifted from smaller local producers to larger companies that have become multinational in their production and marketing operations. These include Driscoll

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Fig. 3. Individually quick-frozen (IQF) raspberries. (photo by H.K. Hall).

Strawberry Associates (Watsonville, California) (DSA), Hortifrut, Inc. (Santiago, Chile, and Naples, Florida), and Redbridge/Redeva (Peterborough, U.K.), as breeders, growers, and marketers, and Plant Sciences (Watsonville, California), and Five Aces Breeding, LLC (Laurel, Maryland) as producers of new cultivars for multinational producers and marketers. DSA spans both these roles, having production bases in several countries. It licenses cultivars to producers and marketers, such as Auzfresh in Australia and KG Fruits/Berry Gardens in the United Kingdom. Many state-funded breeding programs have been terminated and new programs have been initiated by private companies with a large stake in fresh-market production. Larger process-raspberry producers and nursery companies also have taken a stake in the development of new cultivars. High-quality processing types with more dependable production and reduced problems with pests and diseases are promised, but these are likely to be tied to certain markets or breeding groups, and not free for all to access. A. Preface Cultivated species of Rubus (Rosaceae) became important horticultural crops in the 20th century due in large part to the efforts of plant breeders throughout the world. Detailed reviews of blackberry breeding

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and genetics have been summarized in two issues of Plant Breeding Reviews by Hall (1990) and Clark et al. (2007). Our intention in this review was to do the same for raspberry, Rubus L. tribe rubae. Subsequently, the breadth of material warranted the publication of the review as a separate issue of Plant Breeding Reviews. Previously combined reviews of blackberry and raspberry breeding or reviews on aspects of raspberry breeding have been published by Darrow (1937; 1967), Haskell (1961), Sherman and Sharpe (1971), Ourecky (1975b), Jennings (1988), Keep (1988; 1989), Dale et al. (1989), Dale (1991), and Daubeny (1996). The first other review exclusively of raspberry breeding is Chapter 12, written by Finn (2008) in Temperate Fruit Crop Breeding. Germplasm to Genomics (Hancock 2008). B. Origin and Speciation 1. Dispersal. Raspberries are included among species of the genus Rubus L., Rosaceae Juss., nom. cons. Focke (1910, 1911, 1914) suggested division of the genus into 12 subgenera, and subsequent taxonomists have repeated his judgment. However, many of these were defined by similar morphological traits that have been shown to be polyphylogenic in molecular analysis (Alice and Campbell 1999). The United States Department of Agriculture Germplasm Resources Information Network (GRIN) recognizes 15 subgenera (GRIN 2007). A fruit of tribe Rubeae is an aggregate of drupelets that separate as a unit from a conical receptacle when ripe. Species in 5 Rubus subgenera—Idaeobatus, Cylactus, Anoplobatus, Chamaemorus, and Malachobatus—have this character. Although the main economic development in the commercial raspberry has thus far taken place in subgenus Idaeobatus, additional subgenera are mentioned because they may become larger contributors for the raspberry gene pool in future breeding efforts. R. idaeus L., the typic red raspberry species of the Idaeobatus, originated near the Ida Mountains of Asia Minor, now Turkey (Daubeny 1996; Hedrick 1925; Jennings 1988; Roach 1988). Idaeobatus contains about 200 wild species within nine sections. Most raspberry species are diploid ð2n ¼ 2x ¼ 14Þ, with a few triploid and tetraploid types (Thompson 1995a,b, 1997). Idaeobatus species are concentrated in northern Asia but are also located in Africa, Australia, Europe, and North America (Jennings 1988). The greatest diversity is found in southwest China, the likely center of origin of the subgenus. Raspberry species from the Rubus subgenera Cylactis (Arctic raspberry), Idaeobatus (raspberries), Anaplobatus (flowering raspberries), and Orobatus are native throughout the northern hemisphere,

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primarily in the temperate, cool temperate, cold temperate, and subarctic climatic zones. In addition, a few species are also found in the tropics and the southern hemisphere. The main center of diversity is in Asia, principally within the borders of modern-day China, but extending southward through the Himalayas, into Bhutan and India and eastward into Korea and Japan. Locations more distant from this region have fewer species and less variability within the localized species. In contrast, some distant species—for example, the flowering raspberries and black raspberries of North America—show many differences from species found near the center of diversity. Malachobatus is also found mostly in China, though some are distributed in Malaysia and Australia. Raspberries, like other Rubus species, are adapted to consumption and spread by animals, particularly by birds and small mammals, which provide effective seed treatment. Normally they require scarification and stratification for germination to occur, and seed germination is promoted by light. Stratification requirements may be reduced in species adapted to either very cold or very warm conditions, allowing immediate germination when environmental conditions are suitable. The spread of raspberry species was likely from the Chinese center of raspberry diversity to the entire northern hemisphere, and speciation has occurred in response to isolation combined with genetic drift, selection pressure from different environments, and segregation among seedling populations spread and propagated by birds. The endemic natural ranges of present-day cultivated raspberry species are as follows: 1. Rubus subgenera Cylactis (Arctic raspberry) circumpolar above the Arctic Circle. 2. R. idaeus L. subsp. vulgatus (the European red raspberry—referred to as R. idaeus in this review) from Siberia to the United Kingdom. 3. R. idaeus L. subsp. strigosus Michx. (the North American red raspberry—referred to as R. strigosus in this review) from Nova Scotia to Alaska. 4. R. crataegifolius Bunge (the Korean tree raspberry) from eastern China through Korea and Japan. 5. R. coreanus Miquel (the Korean black raspberry) from eastern China through Korea and Japan. 6. R. occidentalis L. (the black raspberry) from New Brunswick to Ontario, south to Georgia and Missouri. 7. Adapted ranges of many nondomesticated or noncultivated raspberry species are available on the World Wide Web.

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2. Environmental Adaptation. Raspberry species have a wide range of adaptation, from cold subarctic conditions inside the Arctic Circle to very warm or hot tropical conditions in Southeast Asia, Australia, and Africa, from very dry to very wet conditions, from high soil fertility to low, from low to high altitude, and from full light conditions to very low light as found within forest or jungle (Dale et al. 1994). Species from the subgenus Cylactis and Rubus chamaemorus L. are adapted to the cold conditions and short summers found above the Arctic Circle through low growth or underground rhizomes and short flowering laterals that spring up from the ground. Flowering and fruit production occurs in a short period, and the plant is protected from winter cold by keeping most of its growth underground or close to the surface. These species are also found farther south at higher altitudes. Cold-hardiness is also found in European, North American, and Asian raspberry species and is important for adaptation to colder environments in Central Europe and more northern locations in continental North America. Tropical species are adapted to low chill conditions and very high temperatures by requiring less chill accumulation to break dormancy and having a higher temperature tolerance (Jennings 1988; Natural Food 2006; Ourecky 1975b). Adaptation to high temperature conditions also is present to allow fruit to escape the effects of sunburn at high temperatures or fruit scald immediately after rainfall in high light and warm conditions. Adaptation to high light levels and high temperatures exists in the raspberry germplasm. The use of species with these traits will assist in developing adapted types suitable for growing in subtropical and tropical conditions where there is increasing interest in growing raspberries commercially. Tropical and subtropical species have been used in developing new cultivars suited to low-chill conditions in California (Fear and Meyer 1993) and the very warm summer conditions of southern and eastern states in the United States (Jennings 1988; Stafne et al. 2001). Raspberry cultivars are well adapted to deep, well-drained soils, but, as the availability of high-quality land has become more restricted, growers have been forced to use heavier and wetter soils. Little tolerance to these conditions exists in red raspberry cultivars, but several species in Asia and North America have the potential to give adaptation to these conditions (Ourecky 1975b). For example R. spectabilis Pursh is adapted to wetter locations near streams and could be used as a parent for this trait.

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Fig. 4. Maxine Thompson and the low-growing Rubus crassifolius, in Guizhou, China. (photo by J. Postman).

Adaptation to low soil moisture or drought exists among raspberry species (Daubeny 1996; Drain 1939; Hull 1969; Jennings 1988; Ourecky 1975b; Overcash 1972), especially in R. strigosus, but selection for drought resistance has not been intentionally utilized in breeding for new raspberry cultivars. 3. Diversity. A great range of diversity exists among raspberry species, from low-growing or prostrate species such as R. chamaemorus L. and R. crassifolius (Fig. 4), less than 0.25 cm tall, to some that grow with thick blackberry-like canes, such as R. corchorifolius (Fig. 5), to very large spreading types such as R. ellipticus that grow 4 to 6 m tall with canes up to 10 cm thick (Darrow 1937). Some species are very upright, especially when grown in cool conditions, but others are spreading or prostrate. Temperate-adapted upright types frequently are less upright or even spreading when grown in warmer subtropical conditions. Leaves vary from entire or lobed to pinnately compound, with diameters reduced to less than 5 mm to 20 cm (Plate 1D). Most raspberry species have a biennial/perennial growth habit, producing vegetative biennial primocanes from the perennial crown in the first year and fruiting laterals on them in the second year, after which the canes senesce and die. Some species, such as R. odoratus, are fully perennial, having canes that persist and bear fruit year after year without dying off. While R. odoratus has been used in raspberry breeding, no selection has been focused on retaining the perennial trait.

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Fig. 5. Rubus corchorifolius, with large blackberrylike canes. (photo by M. Thompson).

Other species are fully annual in their fruiting habit, with fruit produced on primocanes or on fruiting laterals sent up from the ground (as in R. arcticus), but the underground portion of the plant is perennial as in the biennial species. Some species have biennial canes but have some fruit on primocanes like the annual fruiting types. This trait has been utilized in cultivated R. idaeus to produce fully primocane fruiting cultivars that bear most of their crop on primocane growth. Flower and fruit size, shape, color, flavor, texture, and architecture vary considerably in raspberry species (Plate 1). Rubus idaeus and R. strigosus each have small flowers with small white petals and small to moderate-size sepals, usually 5 of each. These surround a receptacle with usually 30 to 60 ovules that develop into drupelets in the mature fruit. However, some raspberry species have considerably larger flowers with larger and more numerous petals, and sometimes over 500 ovules on the receptacle, as in R. sumatranus. Flower color in some species is very distinctive, with purple-lilac color in R. odoratus, pink in R. parvifolius, red-purple in R. spectabilis, and a deep rich red color in some Chinese species. Drupelet size is very small in many wild raspberry species, but it is large in some, such as the tetraploid wild type ‘‘Fengmanhong’’ (species as yet unconfirmed, but it has the appearance of a 4x variant of R. parvifolius) as found in Northern China (H. Dai, pers. comm.). Overall fruit size is also variable in the wild, with some species, such as the natural tetraploid ‘‘Fengmanhong,’’ with some fruit over 5 g in weight (Fig. 6). Some clones with very large fruit of more than 5 cm long

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Fig. 6. ‘Fengmanhong’ tetraploid Rubus parvifolius photographed at Shenyang Agricultural University. (photo by H.K. Hall).

and 2.5 cm wide have been observed among wild R. strigosus in northwest Canada and southeast Alaska but no written reports have been published on these types (H.K. Hall, pers. comm.). Thin drupelet walls of fruit are common in both cultivated raspberries and wild raspberry species, making fruit from some cultivars and wild types prone to collapse when stacked in a clamshell several layers deep, and very easy to crush. Nevertheless, certain wild species, such as R. pileatus, have compact fruit with a small internal cavity and strong resilience and resistance to compaction (Fig. 7). R. pileatus also has very good berry integrity due to strong drupelet coherence and hairiness. This is a trait of potential value in breeding new fresh market cultivars that do not crumble, especially when picked early for extended shelf life. The extreme hairiness of R. pileatus over the fruit is not displayed in progenies of crosses with red raspberry, but there appears to be increased hairs holding drupelets together and improving coherence. Fruit texture is soft in many wild raspberry species, but very firm species offer good prospects for breeding firmness into cultivated types, similar to the use of ‘Cumberland’ (R. occidentalis) (Fig. 8), which was used as a source of firmness for many cultivars in the EMR and SCRI raspberry breeding programs. Considerable variation in the ease of detachment is also seen in wild raspberry species, with some species, such as R. palmatus, being very

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Fig. 7. Rubus pileatus, a very hirsute Asiatic raspberry. (photo by SCRI).

Fig. 8. ‘Cumberland’ black raspberry (Hedrick 1925).

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difficult to remove (H.K. Hall, pers. observ.). Other species detach very easily and may spontaneously fall off when reaching full ripeness (E. Keep, pers. comm.). Ease of detachment may vary widely within species as well. Populations utilizing R. strigosus segregate for ease of detachment. Many genotypes display strong adherence until fully ripe; these include some cultivars of R. idaeus, such as ‘Titan’ (Plate 3D) (C. Weber, pers. observ.). Cultivated raspberries are very susceptible to cane and fruit Botrytis infection and to other diseases. Susceptibility to disease is also common among wild raspberry species, but some species, such as R. pileatus have significant resistance to Botrytis. These could be used to introgress resistance into the cultivated types. Significant leaf and cane disease resistance is also seen in some species. Flavor and aroma of raspberry species is highly variable with a range extending from ‘‘inedible’’ to ‘‘delicious.’’ With the demand for highquality fruit in the fresh market, the use of wild types such as R. deliciosa and R. niveus as sources of high aroma and flavor will become important for the future of the crop. Considerable variation exists among raspberry species in time of bud break, flowering, interval from flowering to ripening, and time of fruit ripeness. R. coreanus accessions have been described that are very early flowering and fruiting (Jennings 1988). Even late-fruiting types, such as R. niveus, can give rise to early-fruiting types through transgressive segregation (Hall, pers. observ.). R. spectabilis has been a source of earliness for both floricane and primocane fruiting types (Keep 1984b). Very little of the available diversity in raspberry species has been explored, and few accessions from them used in raspberry breeding. Much Idaeobatus germplasm is yet to be evaluated and used in breeding to capture diverse traits that are seen among the wild species. There is also at least as much unseen genetic variability in these species that can only be revealed by crossing them with cultivated types, growing out F1 seedlings and using them for selfing, back crossing, and inbreeding. 4. Traditional Uses from the Wild. Wild raspberries have been gathered from before the time of written history, and the presence of seed in early sites of human habitation shows the fondness of the fruit for fresh consumption (Finn et al. 2002). Even to the present date, this practice continues in areas where wild raspberries are plentiful and productive, as in Northeast China, where wild R. crataegifolius is gathered and sold commercially (H.K. Hall, pers. observ.) (Fig. 9). Raspberries have also been used as a decoction for medicinal purposes.

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Fig. 9. Rubus crataegifolius: (A) Harvested from the wild in China. (photo by H.K. Hall); (B) Fruits in a market in Harbin. (photo by J. Postman).

Even now raspberry juice is used as a herbal remedy (Roach 1985), as an additive to water for birds to reduce intestinal infections, and as a supplement for horses and pigs to reduce problems with stomach infections (Herbal remedies using raspberry 2003). Raspberry leaf tea has long been known as a muscle relaxant, especially for females at the time of menstruation and during childbirth (Ryan et al. 2001); similar activity is reported in animals. Raspberries have also traditionally been used as a tincture, made by steeping raspberry fruit in wine vinegar, straining, boiling, skimming, and bottling. This product has been used to treat fevers, arthritis, and gout (Caughlan 2001). Raspberries have also been used extensively for home preserves, canned, processed as jams or jellies, or used to make juices, for winemaking, and for pies and in pastries, snack bars, and tarts. C History of Improvement 1. Domestication. A range of raspberry species have entered cultivation in different parts of the world, but Rubus idaeus L. is the main domesticated type. Modern-day cultivars are derived mainly from the European red raspberry (R. idaeus subsp. vulgatus) and the North American red raspberry (R. idaeus subsp. strigosus), referred to as R. idaeus and R. strigosus, respectively, in this review. Cultivated R. idaeus differs significantly from original wild types and is most improved and cultivated among raspberry species. However, the entire improved raspberry germplasm pool is based on very few accessions of R. idaeus and R. strigosus. This was examined in detail by Dale et al. (1993), who determined the diversity of 137 cultivars of known pedigrees released between 1960 and 1993. These were derived from 50 founding clones, of which half are represented only once or twice among the 137 descendants. In the remainder, 2 species were

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used for crossing and may have made no genetic contribution. Also there were 3 pairs of parent and offspring, reducing the total number of founding clones for the majority of raspberry cultivars to just 20. Among these 20 clones, ‘Hudson River Antwerp’ was in the background of 110 of the cultivars, ‘Lloyd George’ of 108, and ‘English Globe’ and ‘Highland Hardy’ of 90 (through ‘Marlboro’) For this review, a raspberry pedigree database with almost 6,000 entries was examined to determine how many of the cultivars listed in Hedrick’s Small Fruits of New York (1925) were recorded as being part of the pedigree of cultivars developed since that time (H.K. Hall, pers. observ.). This database contains pedigrees of most of the world’s raspberry cultivars, plus significant numbers of selections from several major international raspberry breeding programs. The total number of cultivars from The Small Fruits of New York represented in the database and used in breeding was 25; 12 were cultivars developed by private or public breeders, and the remainder represented unique accessions of either R. idaeus or R. strigosus. The 25 cultivars were used 204 times in breeding. Among them, ‘Lloyd George’ (Plate 2C) was used more than 25% of the time; ‘Latham’ (Plate 3F), ‘Cuthbert’ (Plate 2B), and ‘Newman’ (Fig. 10) combined for a further 35%; and ‘Viking’, ‘Ranere’, ‘June’, and ‘Herbert’ combined for an additional 15%. In total, over 75% of the genetic input for modern cultivars from this material was derived from only 8 cultivars. The remaining almost 25% brought the total of founding parents up to at most 25 accessions from the wild incorporated prior to 1925. These were 12 accessions of R. idaeus, 11 of R. strigosus, 2 of R. occidentalis, 1 of R. innominatus. The remaining accession was an unknown species from China. In total, more than 400 clones were identified in Hedrick’s 1925 review. Many of these were generated through the actions of humans, either by deliberate crossing or through chance seedlings associated with plantings of improved germplasm from either North America or Europe. Eighty-three of these were listed with at least one known or assumed parent. Nevertheless, almost all of this diversity has been lost to modern-day breeders. Since 1925, the larger raspberry breeding programs in Europe and North America have introduced new germplasm from R. idaeus and from R. strigosus numerous times. Only a small number of new accessions have been successfully incorporated in breeding programs, in spite of many wild populations being grown (Haskell 1960b; Jennings 1963b; Keep 1972; Misˇic´ and Tesovic 1973; Øydvin 1970; Rousi 1965; Rozonova 1939a ). In North America, similar assessments of seedling populations have been made at Prince George in British

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Fig. 10. ‘Newman’ red raspberry (Hedrick 1925).

Columbia (Van Adrichem 1972). Further efforts to introgress new genetics from R. strigosus have been made in the Agriculture and AgriFood Canada’s (AAFC’s) Pacific Agri-Food Research Centre in the British Columbia (PARC-BC), Cornell University (NY), and Oregon (ORUS) programs (Kempler and Daubeny 2008; C. Weber pers. observ.). There the use of R. strigosus has primarily been through selection for various traits and introgression of these into material better suited for commercial production. Much more diversity is available for breeding use, but lack of resources in most programs limits its utilization from being done systematically on a significant scale (Daubeny 1997b). In the process of domestication of the red raspberry, germplasm from both R. idaeus and R. strigosus has been important. A number of traits have been assembled in modern-day cultivars that occur independently and sometimes infrequently in the wild. Traits of primary importance

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include self-fertility; resistance to some diseases, especially viruses; large fruit size; strong upright growth; and reduced numbers of new canes. These attributes are essential in modern raspberry cultivars, enabling the plants to grow in a manageable fashion, to produce high yields, and to survive for an extended period. Red raspberry was initially brought into cultivation in Europe using R. idaeus–derived clones. These were planted in North America after the European settlement (Jennings 1988). Local R. strigosus selections proved superior in some traits, especially in climatic adaptation and resistance to disease. During the 19th century, a wide range of raspberry cultivars on each side of the Atlantic were developed using both subspecies. Political boundaries also affected the domestication and development of the raspberry, especially in the isolation of eastern Europe from western Europe and North America in most of the 20th century. Only the earliest improved cultivars using germplasm from both sides of the Atlantic were available in eastern Europe, and most of the cultivars developed in the former Union of Soviet Socialist Republics (USSR) and allied countries have not had the benefit of access to many of the more recent cultivars developed in the West. Nevertheless, there have been very large breeding efforts in eastern Europe, using early western germplasm from Europe and North America, local selections and cultivars, and limited new introductions of EMR and SCRI germplasm, which have not been sufficiently winter hardy for climatic conditions in most of the former USSR. However, cultivars have been produced that are able to withstand local climatic conditions. New cultivars have helped invigorate this industry, which still produces almost half of the world’s raspberries. Trials of new cultivars from the Russian Federation are under way in China but not yet in western countries, as far as authors of this review have been able to determine. Improved plant traits among domesticated red raspberries include vigorous upright growth, reduced cane number, resistance to diseases, good lateral attachment, high fruit number per lateral, adaptation to specific environmental conditions, and enhancement of the primocane fruiting trait found only with weak expression in the wild. Fruiting has been improved with the selection of self-fertile types with large fruit size, improved firmness, enhanced flavor and color, high yield, and ease of harvest. Modern-day plant breeding continues the process of domestication of the red raspberry, improving the cultivated types to make them more appreciated by the consumer and profitable for the grower. Separate domestication events have taken place with other raspberry species in Europe, Asia, and North America, including Rubus arcticus L., R. crataegifolius, R. coreanus, and R. occidentalis. In Northern

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Europe, efforts have been made to domesticate the Arctic raspberry, R. arcticus, especially through the efforts of researchers at the North Savo Agricultural Experiment Station at Maaninka in Finland (Holloway 1982). Problems encountered with this species include low productivity, small fruit size, extended fruiting season, self-infertility, and strong adherence of fruit to the receptacle, making harvest difficult. Attempts have been made to cross R. arcticus with the red raspberry, but the hybrid retained has not been successfully backcrossed to R. arcticus to introgress desirable traits. Backcrosses to R. idaeus have taken generations to restore economic traits by which time the distinctive flavor of R. arcticus was almost completely lost (Holloway 1982). In Sweden, attempts to produce an improved arctic raspberry clone have utilized the Alaskan species R. stellarcticus in crosses with R. arcticus to develop improved cultivars with large flavorful fruit (Larsson 1980). Nevertheless, these new cultivars remain self-sterile and have to be picked by cutting the calyx. There remains much to be achieved in completing the domestication of this crop to make it better suited for commercial production. In North America, the black raspberry, R. occidentalis, has been domesticated and named cultivars were bred at the New York Agricultural Experiment Station in Geneva from selections of wild plants throughout the eastern United States. For the past 100 years, fruit have been hand harvested for fresh market and processing; more recently they have been harvested by machine (Funt 2002). As with the other minor raspberry species, the black raspberry has only taken the first steps toward domestication. Commercial cultivars have severe virus problems, root rot, arching growth habit, very spiny canes, and small fruit size. Little diversity has been found in existing cultivars, but further traits for improvement of black raspberries can be found in wild R. occidentalis and in R. leucodermis, the western black raspberry species. The USDA has begun a black raspberry breeding program in Corvallis, Oregon (Fig. 11). A diverse range of Asiatic black raspberry species exists. However, thus far they have not yet been successfully crossed with R. occidentalis cultivars to add diversity for black raspberry cultivar development. R. coreanus has been successfully used in crosses with red raspberry in the EMR program, and useful traits have been introgressed into new red raspberry cultivars. In Asia, many raspberry types are gathered from the wild but few attempts have been made to bring any of these species into cultivation. R. crataegifolius and R. coreanus are the exceptions with several cultivars being released for growers in Korea (Hong et al. 1986; Kim et al. 2006). R. crataegifolius cultivars include ‘Jingu Juegal’ and ‘Jingu

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Fig. 11. Chad Finn, USDA plant geneticist and Rubus breeder, evaluates black raspberry plants. (photo by S. Ausmus).

Whangal’. These cultivars are not widely grown but occupy a small part of raspberry production in this region. In black raspberry (R. occidentalis), a thriving industry has developed in South Korea, with over 4,500-tonne (t) production per year, mainly for winemaking. R. coreanus cultivars have been developed and are being commercialized, also for winemaking (Han et al. 2006; Kim et al. 2002, 2005). R. crataegifolius, R. coreanus, R. innomatus, R. niveus, and other Asiatic species have been widely used in attempts to improve the red raspberry but only as donors for specific traits. Attempts have also been made to domesticate R. parvifolius in the United States as a raspberry type suitable for high-temperature and lowchill conditions, but no commercial or even home gardener cultivars have been released and no industry developed. As with the other Asiatic species, R. parvifolius has been used in breeding to improve the red raspberry, and it has played an important part in the development of the cultivars ‘Dormanred’, ‘Mandarin’ and ‘Southland’ adapted to conditions in southeastern United States. It has been used to impart low-chill adaptation in the HRNZ New Zealand program. R. parvifolius also has been valuable as a source of resistance to fluctuating winter temperatures in the BC1 and BC2 generations (Ballington and Fernandez 2008). 2. Floricane Fruiting. The floricane fruiting trait is the normal means of fruit production for raspberry types, with fruit produced on laterals that develop in the second year after a first year of vegetative growth.

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Most raspberry species devote their reproductive efforts into producing fruit on laterals from second-year canes. The exceptions to this are primocane fruiting species. Of those, R. arcticus has an annual reproductive cycle and R. ellipticus is fully perennial. At present, primocane-fruiting red raspberry types are the only nonfloricane fruiting raspberries cultivated commercially, but efforts are under way to produce primocane-fruiting black raspberries for future commercial production (P. Tallman, pers. comm.). 3. Primocane Fruiting. The primocane-fruiting trait in raspberries occurs naturally in wild R. idaeus, R. strigosus, and R. occidentalis, but the natural expression of this character is limited to a small amount of fruit at the cane tips, often late in the autumn. The primocanefruiting trait also occurs in: cold-climate herbaceous species, including R. arcticus L., R. chamaemorus L., and R. saxatilis L.; in warm-climate species R. illecebrosus Focke; in biennial types; and also in the perennial-caned species R. odoratus L. (Keep 1961). Among wild raspberries and Rubus species expressing the primocane-fruiting trait, fruit size is often small, fruiting nodes are few, branching and lateral formation is limited, and fruit number per lateral or fruiting node is few (Keep 1988). Despite the low yield and poor quality of wild primocanefruiting types, they have been cultivated in European and North American gardens for over 200 years (Mawe and Abercrombie 1778; McMahon 1806). From the earliest times of the domestication of the red raspberry, plants producing some primocane fruit were noted, and early breeders made attempts to enhance this trait. A significant advance was made when varieties with primocane-fruiting expression from the European red raspberry, R. idaeus (‘Lloyd George’) and the North American red raspberry R. strigosus (‘Ranere’ and the numbered selections NY 21289, NY 20903 and NY 20990) were interbred, resulting in the cultivars ‘Marcy’, ‘Indian Summer’, ‘September’ and ‘Zeva Herbsternte’, followed in later generations with ‘Fallred’ and ‘Heritage’ (Plate 3B) (Keep 1988). Keys for the potential success of primocane-fruiting raspberries are good expression of yield components and excellent fruit quality. Lewis (1941) and Haskell (1960a) published theories on simple inheritance of a gene for primocane fruiting, but other studies have shown that inheritance is a complex mechanism (Keep 1988; Slate and Watson 1964; Waldo and Darrow 1941). Keep (1961, 1988) emphasized that the inheritance of primocane fruiting in raspberries was due to the interaction of both genetic and environmental factors. The realization of yield potential of primocane-fruiting raspberries

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depends on the interaction of additive factors for season (vigor, maturity, and earliness) with the local environmental conditions (climate, day-length, nutrition, and water availability) (Keep 1988). Yield potential is determined by fruit size and number, fruit number per cane being dependant on bearing surface or amount of branching and lateral formation on canes combined with cane number per plant (Keep 1988). Significant advances in earliness and in yield potential over the cultivars derived from R. idaeus and R. strigosus have been achieved by breeders at EMR with the introgression of earliness into primocane-fruiting types from R. arcticus, R. odoratus, and R. spectabilis (Keep 1988; Knight 1991). Further progress in the development of primocane-fruiting raspberries has been achieved with the improvement of fruit quality by introgressing quality from floricane-fruiting types, especially through the work of Derek Jennings at SCRI and Medway Fruits (Kent, England) (Jennings 2002). The initial cross making this sort of combination was ‘Glen Moy’  ‘Autumn Bliss’. Large numbers of seedlings from this cross were grown in the United Kingdom, Australia, New Zealand, and the United States, leading to the cultivars ‘Aspiring’, ‘Dinkum,’ and ‘Terri Louise’ and the advanced selections A83-31-B5 from Australia and GEO-1 (parent of ‘Caroline’) from the United States. The combination ‘Comox’ ‘Autumn Bliss’ also produced the high-quality cultivar ‘Bogong’ in Australia. In addition the new cultivars ‘Erika’ and ‘Sugana’ were produced from the cross ‘Tulameen’  ‘Autumn Bliss’. Further crosses were done between the high-quality floricane-fruiting raspberries ‘Glen Lyon’ and the selection SCRI 8216B6 with primocane cultivars and advanced selections from the EMR program to produce advanced selections and cultivars in the Medway Fruits program (Jennings 2002). In the United States, advanced selections and cultivars from EMR, SCRI, and Medway Fruits were crossed with advanced selections in the Maryland program and the DSA program, giving rise to further levels of breeding improvement and advances in yield and quality. D. World Industry The raspberry industry is expanding rapidly around the world, especially in the fresh market and in production for processing in third world countries, where labor is cheap for hand harvest production. Principal driving factors for the recent expansion include:  Sales to new markets around the world in regions where raspberries have not been traditionally grown

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 Improved returns to growers through improved fruit quality and improved growing environmental conditions making the crop dependable  Improved fruit quality, leading to sales of a more appealing product to consumers  Reduced losses by retailers due to the effects of molds and the perishable nature of the crop; thus retailers are keen to stock more raspberries and present more for sale  Recognition of raspberries as a healthy component of diet and the use of raspberries in healthy foods, in drinks such as Bouvrage, and in mineral and health-promoting products such as Maximol (Anewlife 2007; Ella-Drinks 2007). It is difficult to estimate area and production around the world, and no reliable source provides accurate data (Strik 2007). The FAO data, which could give an accurate perspective on this, is clouded through the incorporation of production figures on other berries, which, for example, gives production in Vietnam, where there is no raspberry industry, of over 100,000 t. An estimated area of 71,250 ha is cultivated, and annual production is estimated at around 615,000 t (wild plants harvested not included, except from the Russian Federation) (Table 1). Table 1. World production of raspberries, 2005–2007. Region Russian Federation Serbia and Montenegro USAZ Poland Chile Ukraine Germany Hungary China and KoreaY Canada France England-Scotland Romania Bulgaria Others World

Production (t)

Area (ha)

176,000 90,000 84,000 65,000 64,000 27,000 20,000 20,000 20,000 15,000 8,000 8,000 4,500 3,000 5,000 602,500

15,000 10,500 7,000 13,000 10,500 5,000 2,500 3,200 3,200 2,800 1,000 1,300 250 200 1,300 71,250

Source: Coburn 2007; FAO 2007; IFEPoland 2007. Black raspberries comprise just over 2% of this total. Y Black raspberries comprise almost 25% of this total, entirely in Korea (Lee Dong Hee, pers. commun.). Z

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These figures are a compilation of FAO data, personal information, and communications and data from the Oregon Raspberry and Blackberry Commission. As production varies each year according to climatic conditions, the highest yield for each region over the years 2005 to 2007 has been used in an attempt to eliminate weather-based variation in production. 1. North America. In North America, raspberry production has moved from predominant production for processing to a significant fresh market production base. Process production is almost entirely machine harvested and is based in Oregon, Washington, and British Columbia, with Washington being the largest producer. The main cultivar for processing is ‘Meeker’, with most of the plantings in the Pacific Northwest still using this cultivar, 40 years after its release in 1967 and nearly 60 years after the cross was done in 1950. ‘Meeker’ has retained its position as the leading process cultivar in this region not only because of its fruit size, flavor and processing character, root rot resistance, and adaptation to this climate but because of the maintenance of high health propagation stocks and a very effective certification program. ‘Meeker’ is susceptible to raspberry bushy dwarf virus (RBDV). Recent plantings in this region are being infected and requiring replacement after as little as five years. In addition, ‘Meeker’ root rot resistance is no longer sufficient to keep plantings root-rot free in the Pacific Northwest, likely through a combination of plantings on poorer soils and the presence of more virulent pathotypes of the disease. Over 60% of the total production is for fresh market with most of this production based in California. (In 2006, the Californian production was 63% of the total and almost all was sold in the fresh market.) The leading producer of fresh market raspberries in North America is DSA, with up to 80% of the market. Their first dual-cropping raspberries were developed by Earl Goldsmith and Joseph Reiter in 1937. Commercial production of ‘Stonehurst’ and ‘Sweetbriar’ was initiated by Sweetbriar’s when plants were patented in 1979 (Daubeny 1991; Reiter 1979b). The Sweetbriar Company has now been amalgamated with DSA and fruit is sold under the Driscoll’s label. Current cultivars have been developed from interbreeding Sweetbriar cultivars and by introgressing traits from the world’s leading raspberries into the unique DSA germplasm. Production for fresh market has expanded in recent years to Southern California, Mexico, and Guatemala, using low-chill cultivars and taking advantage of higher-altitude production regions in Mexico and Guatemala. These regions are likely to be expanded in the future to

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provide an off-season supply for the rest of North America, especially if transportation and hygiene issues are resolved in Mexico and Guatemala. In contrast to the expansion of large company production, there is a resurgence of farmers’ markets in North America, which will need to be serviced with the development of new cultivars for the future. 2. Australasia. Australia and New Zealand have grown raspberries for local consumption and for export since the 19th century. Shipments for export to the United Kingdom were sent preserved by sulfur dioxide by sailing ship prior to the advent of steamships. Frozen fruit also were shipped prior to the turn of the 20th century. Production of raspberries for processing in both Australia and New Zealand was significant through the 20th century, but current production in both countries is focused on the fresh market. Process production has diminished significantly; total production is approximately 800 t. 3. China and East Asia. A small raspberry production industry has been present in China for almost 100 years, centred in the northeastern province of Heilongjiang. Raspberries were initially imported with Russian construction engineers when they came to assist the Chinese with the development of a railway infrastructure in the 1920s (Yang 2002). In the 1970s, raspberries became a viable commercial crop, and production increased significantly in the rural area around Shangzhi city. Production is between 6,000 and 20,000 t. Both smaller producers and larger companies are gearing up for increased production of raspberries in China, although there needs to be significant improvements in cultivars grown both for environmental adaptation and for suitability to market niches targeted by producers. Significant capital investment is needed to carry out the expansion desired by some of the larger producers (H.K. Hall, pers. observ.). Raspberries are also grown and produced in Korea, with locally developed cultivars of red raspberry (R. crataegifolius) and black raspberry (R. coreanus) being grown and consumed in addition to cultivars of R. idaeus and R. occidentalis from which traditional cultivars of red and black raspberry have been developed. Production of red raspberries is low but black raspberry production is over 4500 t. Demand for both red and black raspberries is increasing, as is production and market value. Consumption is also increasing in Japan; this country promises to become a significant market for the future. 4. Russian Federation and the Ukraine. Russia has a long history of raspberry production, and it remains the world’s largest producer,

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although some of the production is still harvested from the wild. Around 176,000 t are produced annually in the Russian Federation and up to 27,000 t in the Ukraine. Little information is available in the West about production and cultivars grown in these areas, but recent information available on the Internet and in publications by Kichina and Kazakov show exciting new cultivar developments in fruit size, production, and adaptive range, especially into very cold locations and north into high latitudes (Kazakov 2006; Kichina 2004, 2005a). 5. Europe. The largest traditional producers in western Europe are Germany, France, and the United Kingdom. Germany has historically been the largest, currently producing about 20,000 t, compared with France and the United Kingdom with about 8,000 t each. In the United Kingdom, historical production has been for the fresh market in England and the process market in Scotland. Process production has significantly declined in recent years and fresh market production in Scotland has risen dramatically (Jennings et. al. 2008). Around 80% of fresh market production in the United Kingdom is in tunnels or under glass, to reduce the risk of weather-related drops in quality or losses due to spoilage. Fresh-market sales of raspberries have significantly increased there in recent years, and high-quality fruit is now found in the market year round, from local or external sources. Cultivars grown in the United Kingdom are locally produced, from the PARC-BC raspberry breeding program or from the DSA breeding program in California. Cultivars ‘Glen Ample’ and ‘Tulameen’ (Plates 2G and 6C) dominate U. K. raspberry production, and production of ‘Octavia’ is increasing to become the third significant cultivar (Knight and Ferna´ndez Ferna´ndez 2008a). Further cultivars produced in minor quantities are ‘Autumn Bliss’, DSA cultivars, ‘Himbo Top’, ‘Joan Squire’, ‘Polana’, and ‘Polka’. In France, there has been a tradition of growing cultivars such as ‘Rose de Cote d’Or’, with very strong flavor and aroma, which is highly favored by culinary and winemaking specialists. However, this cultivar and other local varieties have now been mostly replaced by cultivars from major breeding programs in the United Kingdom or United States, with ‘Meeker’ being the major cultivar produced at the present time. In Germany, in spite of having the largest production in western Europe, production is largely based around old cultivars or cultivars imported to the country. Germany has also become a major importer of raspberries for fresh sales and for processing. 6. Eastern Europe. Until recently, Eastern European countries were outside of the European Community (EC) and they were able to rely on

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cheaper local labor, subsidies, and production incentives to bolster production of cheap raspberries for sales to the EC. However, recently Poland (65,000 t), Hungary (10,000 t), Romania (4,500 t), and Bulgaria (3,000 t) have joined the EC. It remains unclear how long prices will be reduced for raspberry production from these new EC states and whether their production will grow or diminish under the new political structure. The largest and only remaining producer in Eastern Europe outside the EC is Serbia (90,000 t) with production still mostly on holdings of 2 ha or less. When sanctions were placed on Serbia after the Kosovo war, production dropped significantly, although channels for sale of much of the fruit were found through neighboring countries. Since the relaxation of sanctions, production has increased and is mostly sold as frozen fruit to the EC and other parts of the world. 7. Southern Europe. Spain, Portugal, and southern Italy were not able to grow raspberries commercially until recently, due to poor adaptation of cultivars. However, in recent years, two changes have made raspberry production possible and profitable in these areas. First, growers have adopted cultural methods that utilize natural chill from other cooler locations to vernalize canes for production in these warm climate locations or artificial chill has been applied to canes grown in these areas. Both methods use long canes that have been cool-stored until planting for producing high-density, short-lived plantations, usually under tunnels for producing high-value crops targeting the out-of-season markets farther north. Spanish growers have successfully manipulated ‘Glen Lyon’ using this system since the 1990s. New ‘Glen Lyon’ fields are planted every three weeks by growers to give a continuous ongoing harvest. When harvest is complete in each field, new canes are dug and cool-stored for 50 days before replanting (D.L. Jennings, pers. comm.). Second, new primocane-fruiting cultivars like ’Joan Squire’ can be manipulated for production in Southern Europe for the same high-value, out-of-season markets. When canes are cut back to ten nodes fruiting occurs on replacement canes after fifteen weeks, or twenty weeks when cut back to the ground. 8. Africa. Most of Africa is too hot for raspberry production, and until recently the only limited production has been in South Africa. More recently, production has been initiated in Morocco, Algeria, and Kenya, using the same cultivars and techniques as used in southern Europe.

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9. South America. Since the 1970s, raspberry production in Chile has grown rapidly. By 2007, Chilean raspberry production was fourth in the world after the Russian Federation, Serbia and Montenegro, and the United States, with an annual production of around 64,000 t. This has been made possible by cheap labor, through the development of effective trade relations with the United States and Europe, and through effective marketing. Raspberry growing in Chile is very productive, and plants appear very well adapted to the local conditions. Around 80% of the production is of ‘Heritage’. Other primocane-fruiting cultivars such as ‘Autumn Bliss’ appear healthy and vigorous after 12 years of production. In Chile, there are large areas that appear well suited for raspberry production. With the development of productive, locally adapted cultivars, production there has the potential to increase so that Chile becomes the world’s leading producer. Raspberries are also produced in Argentina, but the developments in Chile far outstrip those in Argentina. E. Uses Many traditional uses of red raspberries continue today, and in some locations older uses of fresh raspberry fruit are being revived, especially for medicinal use, where scientific studies are confirming traditional health-giving properties. Today fresh raspberries are increasing in popularity, where they are consumed as a snack, as a dessert, sometimes with sugar and dairy products (cream, ice cream, yogurt, etc.), and with increasing frequency as a health-giving addition to breakfast. Fresh raspberries are also used as a garnish on bakery products and in fruit salads. Many other uses are found for fresh raspberries, but these are through processing and are covered under process raspberries, even though in most cases the use of fresh fruit would be better and more nutritious. Many raspberries are stored as a frozen product before their ultimate use in processing. Preservation as frozen products is common as individually quick frozen (IQF), block frozen pulp, or concentrate. Pulp is often screened before concentration. Screened pulp has the solids removed before being clarified for juice or juice concentrate. Canning continues to be practiced, it is rapidly diminishing as a source for industrial or processing use. Drying, by heating, low-pressure evaporation, or freeze drying, is also popular as a first step from fresh harvest, before shipping and use for processing. Drying is also used to make raspberry fruit leather or multifruit leather for snack food sales.

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Preserving of fruit pulp under sulfur dioxide as used in the 19th and early 20th centuries is now almost gone. Wherever raspberries are used for processing, convenience is an increasingly important factor for processors who are becoming less interested in buying block frozen packs, pails, or drums of fruit for use in their factories, even when the price is lower. For this reason IQF fruit is becoming much more popular as the preferred source of process raspberries for factory use. IQF fruit can be defrosted quickly, used with less waste, and results in a higher-quality product. Use in the bakery trade, especially in smaller businesses, has increased through the availability of IQF fruit. Bakery products using raspberries include pies, tarts, fruit rolls, biscuits, and pastries. Raspberries are also used as juice to make flavored milk and as pulp, prepared cooked purees with sugar, and/or as whole fruits in combination with dairy products to make yogurt, cheesecake, and ice cream. IQF raspberries are also used in ‘‘ice cream machines’’ to make real-fruit ice cream by grinding frozen berries with plain or vanilla ice cream. IQF raspberries are also used to make sorbets for a nondairy, ice fruit dessert. Raspberry concentrate, juice, and freeze-dried fruit are used as components of healthful breakfast cereals, especially in Muesli and other products, such as Fruity Bix in Australia and New Zealand (Sanitarium Health Food Company 2007). Raspberries are also processed by cooking with sugar to make jam and, when the seed is removed, raspberry jelly. Similar processed products are made for diabetics and those on sugar-free or lower carbohydrate diets. Jams and jellies are also made without cooking and preserved for storage by pasteurization or freezing. Raspberries are used in health products such as Maximol (Anewlife 2007) and as flavoring for medicines to make them palatable for children. They also are used for intestinal health and reduction of stomach infections caused by bacteria. In Australia, raspberry juice is added to water supplies of livestock or birds to reduce or eliminate stomach infections. F. Breeding Objectives Breeding objectives for new raspberry cultivars are focused on morphological traits (uprightness, spinelessness, and cane quality), yield, fruit quality, pest and disease resistance, and environmental adaptation (Daubeny 1996; Jennings 1988; Ourecky 1975a). The relative importance of each of these objectives within a breeding program is tied closely to the nature of the local industry, the markets (fresh for pick

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your own or local sales, fresh for shipping and marketing some distance from the production region, processed for jams and concentrate, juice, winemaking etc.), the local or market traditions, and the restrictions of the local environment, including pests and diseases. In the last 30 years, raspberry production in the western world has changed significantly, from largely processed fruit to a high proportion of fresh-market sales. Process production in the North American traditional production region of the Pacific Northwest has moved from hand to mechanized harvest. In Europe, the Scottish industry made an attempt to do likewise, but this was inhibited by the lack of an economic cultivar/machine combination. Western producers have also come under pressure from hand harvest, processing quality production in South America and in Eastern Europe, where labor costs are low and small family holdings are the most important producers for the local industries. The processed raspberry crop in Scotland has dropped significantly, and 80% of the crop is now produced for the fresh market. China also is poised to make a significant impact as a producer and exporter for markets in the western world. The trend toward fresh-market production resulted from improvements in fruit quality, management, production techniques, quality control, cool chain and handling procedures, and increased sales to consumers through supermarket chains. The move to supermarket sales also has affected the growing conditions and breeding objectives, as the supermarkets insist on having high-quality fresh raspberries available throughout the year. Production has moved to tunnels in Europe and the Americas, and the production region has extended into the subtropics and tropical climatic zones, both of which require new adaptation and quality traits for the production of high-quality fruit. In North America, many of the small producers of raspberries for fresh market sales have disappeared. Sales from large companies have taken their place, and with improvement in quality and storage life, the fresh-market raspberry sector has grown significantly. Large companies producing fruit for this market have moved to breeding and growing their own cultivars. At the same time, inputs to public breeding programs have decreased. In the United Kingdom, many growers have moved to become part of a large grower cooperative, K.G. Fruits/Berry Growers, which has both accessed new cultivars and germplasm from North America and started the development of its own new cultivars in partnership with the public breeding program at EMR. Larger companies have also resorted to sourcing fruit from warmer climates and opposite season production regions in the southern hemisphere.

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Breeding objectives for the North American fresh market have taken on a DSA color and flavor preference, as they have the major share in the marketplace. Color is a light orange-red that does not significantly darken during storage and flavor is sweet, with low acidity and low aromatics. DSA raspberry fruit also has good skin strength, especially at the fruit tip, and moderately firm internal texture. Preferred fruit size is small-medium, as the clamshells for marketing only hold a small quantity of fruit.

II. GERMPLASM RESOURCES, EXPLORATION, AND MAINTENANCE A. Acquisition of New Germplasm By 1937, Darrow realized that while improvements in raspberry had been significant, more could yet be accomplished. Some of the qualities now found separately, that may be combined in raspberries of the future are the very large fruit size of European varieties and newer American productions, immense fruit clusters, great productiveness, firmness, vigor, and resistance to diseases. But there is also a large reservoir of germplasm hardly yet touched by raspberry breeders, in the wild species of Asia and elsewhere, some of which resemble the grape, hawthorn, bamboo, maple, and apple in their leaf forms and vary from low and soft-stemmed plants to plants with stems 3 inches thick and 14 feet high.

Darrow (1937) reported that more than 67 Rubus species from Europe, Asia, North America, and South America had been evaluated for breeding and improvement of raspberries and blackberries. Large collections of Rubus were made by L.H. Bailey and assembled in New York in the first half of the 1900s (Hedrick 1925), but these collections were for pressed voucher specimens to be kept in herbaria rather than as living examples of distributable plant material at a gene bank. Finn and Knight (2002) observed that most raspberry breeding programs evaluate and incorporate new Rubus species germplasm. In Europe, at least 16 species have been evaluated and used as sources of new traits. In North America, at least 58 species have been evaluated and applied in breeding. The EMR program has more frequently incorporated new genes from European species rather than other international species (Jennings 1988; Knight 1993), although at times a range of Asiatic species have been used. The USDA-ARS small fruit

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programs in Oregon and Maryland, and state and regional programs in North Carolina, at Puyallup, Washington (WSU), and Abbotsford, British Columbia (PARC-BC) have more recently focused on Asian species as parents (Finn and Knight 2002; Finn et al. 1999, 2001a, 2002). The U.S. national Rubus gene bank was established at Corvallis, Oregon, in 1981. During the past 27 years, the U.S. Department of Agriculture has sponsored roughly 30 plant-collecting expeditions for small fruits in which at least some Rubus accessions have been obtained (Table 2). However, Rubus continues to be in need of systematic collection, partly because of the great diversity of the genus—these expeditions have only scratched the surface of Rubus species diversity—and partly because successful propagation of wild Rubus has proven difficult. In most of these expeditions, seed lots were obtained. Frequently, in the wild, only a few fruit may be available at the time that collectors were present. Fruit may not be ripe, particularly if collectors were targeting other small fruit genera, such as Fragaria. Unripe fruit usually provide only immature or unfilled seed with low viability. If fruits were absent, clonal propagules may have been collected, but propagation success has been limited. As a result, representatives of only about 56% of wild-collected Rubus now remains alive at the Corvallis gene bank. Since 1996, the advent of handheld global positioning system (GPS) units has permitted specific locality information to be obtained from collection sites. This information will enabled easier re-collection of material when initial establishment of wild material has been unsuccessful. It promises to be a very useful tool for the future. Red, black, and purple raspberries and blackberries are the most economically important cultivated crops derived from the genus Rubus worldwide. However, wherever Rubus is found, species are gathered from the wild and represent an important food and monetary source as a local crop for native peoples. Some examples are: Mora de Castilla (R. glaucus) of Andean South America; R. crataegifolius of northeastern Asia; the Arctic raspberries (R. stellatus, R. arcticus, and R. stellarcticus) and cloudberry (R. chamaemorus) (Fig. 12) of Scandinavia, Newfoundland, and Alaska; R. sachalinensis in Siberia and Sakhalin Island; and R. strigosus in Alaska. Relative to continued development of raspberries for global use, these four species should be collected for better representation in world gene banks. 1. Rubus strigosus (North America)/R. idaeus (Eurasia). Throughout the native range. These two groups of R. idaeus form the

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Table 2. USDA Clonal Germplasm Repository Rubus germplasm collections.

Expedition leader

Year

Mel Westwood Otto Jahn Mel Westwood National Arboretum staff Maxine Thompson Maxine Thompson Jim Ballington, Jim Luby, and Otto Jahn Robert Skirvin Jim Ballington Mark Widrlechner Maxine Thompson Maxine Thompson Jim Ballington, Maxine Thompson Jim Luby Kim Hummer, Naohiro Naruhashi Scott Cameron Maxine Thompson Wes Messinger, Jim Ballington Chad Finn, Jim Luby Kim Hummer, Cathy Wright Maxine Thompson, Chad Finn, Joseph Postman Nat. Arboretum Staff Kim Hummer, Nick Vorsa

1982 1982 1983 1983 1984 1984

Japan, Korea, Taiwan Oregon Hawaii China Syria Minnesota, Wisconsin

158–181 185–187 399–414 423–430 482–484 495–599

1985 1986 1986 1987 1987 1988

Pacific Northwest USA New Zealand Southeast Midwest USA Colorado, USA Pakistan

643–719 745–776 778–798 840–851 861–871 1052–1079

1990 1991

Ecuador Scotland

1248–1295 1296–1384

1991 1992 1992

Japan Chile Guizhou, China

1417–1429 1568–1579 1621–1716

1995 1995 1996

Bolivia Western US Alaska

1789–1812 1827–1860 1875–1903

1996 1996 2001

NE China Ecuador Primorye, Khabarovsk, Russia Armenia Sakhalin, Russia Hokkaido Republic of Georgia Florida

1911–1934 2063–2096 2142–2157

Joseph Postman Andrey Sabitov Kim Hummer, Thomas Davis Joseph Postman Kim Hummer, Paul Lyrene Kim Hummer, Chad Finn, Michael Dossett

2002 2004 2004 2004 2006 2007

Location

Corvallis inventory numbers

Southeastern and Midwestern US

2165–2177 2238–2252 2256–2286 2302–2305 2335–2338 2357–2418

underpinning of the red raspberry industry. They are distributed throughout northern temperate regions with some notable, southern remnant populations. While extensive but haphazard collections representing North America have recently been assembled

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Fig. 12. Rubus chamaemorus collected from Siberia in 2001. (photo by K. Hummer).

by Agriculture and Agri-Food Canada in British Columbia, this species is not well represented from throughout its North American and Eurasian distribution. What sampling has been done has led to the identification of valuable sources of Phytophthora root rot resistance (Kempler and Daubeny 2008). There is special interest in collecting this species from the extremes (wettest, driest, coldest and hottest) of its range. 2. Rubus idaeus (Eurasia) from the former Soviet Union. This is a critical, pressing need. The large Russian collection of R. idaeus is in danger of being lost because of the current economic situation in some of the former Soviet Union states.

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3. Rubus occidentalis. The black raspberry industry, concentrated in Oregon, has relied on wild selections and turn-of-the-20th-century developed cultivars. Three recent collecting trips (Table 2) have obtained new genetic resources of these species. R. leucodermis was collected throughout the Pacific Northwest. R. occidentalis was collected through five southeastern U.S. states of the southern limit of the range and in five states at the midwestern limit of the range. The variability present within these samples is being assessed and may bring about new black raspberry cultivars for commerce. R. occidentalis is worth collecting from much of the adaptive range in North America. Primocane-fruiting black raspberries are being evaluated in several breeding programs throughout the United States (Dossett et al. 2007). 4. Asian Rubus. A major center of origin for Rubus is in China. Flora of China (Lingdi and Boufford 2003) reports to have 208 species, with 139 being endemic. Systematic collections were sponsored by the USDA in 1994 in China’s Guizhou Province and in northeast China in 1996. These collections are being evaluated and potentially valuable germplasm is being incorporated into advanced breeding material. However, no other official U.S. government collecting has been done in China since 2004. To date, the United States and China have not agreed to terms for bilateral collecting agreements as currently required by the International Treaty on Plant Genetic Resources. Although the United States contracted with India in the early 1990s for collection of Rubus and other temperate fruit and nut crops in the Himalayan hills, no plant material was permitted to leave India. Some collecting has been done in Japan, although the target species for that expedition was Fragaria and the ripe fruit of Rubus was unavailable. R. parvifolius has proven to be a valuable germplasm resource in breeding low-chill- and high-temperatureadapted red raspberries. This species needs to be systematically collected in Asia including Japan and Korea. B. Value of Clonal Germplasm Versus Seed Rubus germplasm can be collected as seed extracted from fruit or as clonal or vegetative propagules. Rubus seed is orthodox, and low seed moisture and low temperature extend storage life (Doijode 2001). Seed provides the opportunity to efficiently represent a broad level of diversity. A second advantage is that seed lots, in some cases, can be approved for shipments accommodating some phytosanitary

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certification regulations where plants cannot be shipped. Species’ genetic material is cheaper to collect and maintain as seed than as clones. Disadvantages of seed storage include the potential for storing of nonviable seed. In addition, the optimal procedures for overcoming seed dormancy and germination procedures for most species have not been determined. While the range of diversity represented by seed is higher, time and effort are needed to select useful clones from seed populations. Most seedlings of clones will be not as ‘‘good’’ (i.e., able to meet qualification standards) as their parents. Care must be taken to maintain the integrity, diversity, and heterozygosity of the germplasm contained in the seed lot by ensuring adequate seed lot size (usually > 30) for regeneration efforts. This may be achieved by crossing individual seedlings instead of using open pollinated seed. Sufficient male and female parents are needed to capture the diversity of the original seed lot. Collection of clonal material frequently has advantages. The specific plant phenology and morphology can be observed. Particularly traits useful in identification, such as those of leaves, flowers, and fruit, can be measured. This provides a ready access for identification based on morphology. Fresh or lyophilized leaves can be obtained for molecular studies or for shipment. Pollen can be gathered from flowers, and seed can be gathered from fruits for distribution or additional genetic resource preservation. Clones provide material for evaluation of descriptive traits and can regenerate seed lots. Alternative genetic resource preservation techniques, such as in vitro culture and cryogenic storage of dormant buds or meristematic tissue, can be obtained. If clones are maintained properly, the precise genotype is preserved. There is no problem with inbreeding depression or genetic drift. Diversity is not lost when the collection is regenerated by vegetative propagation. Data can be collected to gather details on growth, morphology, chemistry, and quality. Clones are readily available for use in germplasm improvement. The viability of the genetic resources is evident. Some of the disadvantages of clones include the need to be correctly identified. Clones should consist of a high-quality vegetative plant material, and the accession must be maintained in high health conditions. Clones can easily become infected by diseases and can be prone to accidental damage, especially when kept in the field. Each cultivar or selection requires testing and, if disease infected, requires cleaning up with subsequent diligent maintenance of the diseasefree clones. Raspberries require considerable maintenance and care

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compared to most other berry crops. Trellising is constantly needed. Thorns of the plants are difficult to work with. In field settings, raspberries produce underground suckers that can ‘‘contaminate’’ neighboring plants; taxonomic expertise is required to differentiate between contaminated clones. C. Germplasm Preservation The challenges of maintaining a gene bank representing global Rubus diversity is a daunting task. The USDA-ARS germplasm resources information network (GRIN) recognizes 415 Rubus species and subspecies, with 195 of these represented in the USDA genebank (USDA 2007). This very widespread genus includes species adapted to many niches and ecosystems from sea level to 4,200 meters and from equatorial to arctic zones. Some Rubus genotypes are armed, gregarious, dominant, and overbearing plants with sprawling to upright habit. Others are delicate, petite, understory or prostrate plants requiring precise pH, drainage, light, heat, and cooling for cultivation. Some thrive on arctic hillsides of scree or rock outcroppings, some in peat and sphagnum bogs, some in the temperate forests, some in deserts, and others in tropical jungles. To preserve Rubus germplasm as living plants, provisions must be made for this diversity. The USDA houses the primary Rubus genetic resource collection (230 are raspberry clones belonging to Rubus idaeus, R. sachalinensis, or R. strigosus) as containerized plants in about 300 m2 aphid-proof screenhouses and 230 m2 of polyacrylamide-glazed greenhouses. Secondary collections are temporarily grown in field plots for evaluation or stored locally or off-site by alternative biotechnologies. These include midterm storage (5–10 years) at 1 to 4 C as tissuecultured plants in a walk-in cooler or long-term storage (decades) in a 30-liter liquid nitrogen tank. Other countries that have Rubus gene banks include Argentina, Australia, Belgium, Canada, China, Czech Republic, Finland, France, Hungary, India, Italy, Japan, Kazakhstan, Korea, Netherlands, Norway, New Zealand, Poland, Romania, Russian Federation, South Africa, Sweden, Switzerland, United Kingdom (Bettencourt and Konopka 1989; Diekmann et al. 1994). Intercountry cooperatives that preserve Rubus genetic resources include the European cooperation in the field of scientific and technical research (COST) and the Nordic Genebank. (Euroberry 2007). In addition to clonal germplasm, where preservation of specific genotypes is critical, seeds and pollen are preserved to represent Rubus

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Fig. 13. Scanning electron micrograph of a seed of Rubus idaeus from Armenia. (Image taken by Sugae Wada, Oregon State University).

species diversity. Examination of seed morphology can contribute to the confirmation of the botanical and horticultural identity (Fig. 13). Cleaned seeds can be packaged in airtight envelopes preserved at 20 C in 2.6 m3 chest freezers (Fig. 14). Rubus plants can be grown in environment chambers to simulate conditions in their native climatic

Fig. 14. Seed storage at the USDA Rubus Germplasm Repository, Corvallis: (A) Aluminized bags with seed stored at 20 C. (photo by H.K. Hall); (B) Labeled seed packets. (photo K. Hummer).

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Fig. 15. Screenhouse at the Canadian Clonal Genebank, Harrow, Ontario. (photo by M. Luffman).

zones. Cold-hardy types, which can survive 10 C, can be maintained in screened houses in temperate climates (Fig. 15). This permits chilling units to be obtained naturally, while preventing virus vectors such as aphids from gaining access to the plants. In winter, screenhouses are heated only if the temperature drops below 3 C. Integrated pest management (IPM) is recommended to combine cultural practices, biological control agents, quarantine procedures, and physical exclusions to effectively manage plant diseases, arthropod pests, vertebrate pests, and weeds in the greenhouses, screenhouses, and fields The goal of the IPM program is to maintain pest populations at the lowest acceptable level to provide a healthy plant environment and a safe environment for workers and visitors. Light horticultural oils, insecticidal soap, and biological controls are available when cultural methods alone do not adequately control the problem. Key pests occur in large numbers and are destructive to plant health. Secondary pests include other less important pests. Minor pests include slugs, snails, ants, earwigs, leaf miners, leafrollers, mealy bugs, leaf midges, springtails, sowbugs, millipedes, and mice. Slugs and snails can cause serious damage to herbaceous species, particularly during the dormant season when they feed on roots and rhizomes. Raspberry accessions may also be propagated by dormant root cuttings. Root cuttings are collected during late winter or early spring, from February through March. Hardwood cuttings may also be taken for some species, but little success can be expected from this propagation

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Fig. 16. Technician Jeanine DeNoma (left) and plant physiologist Barbara Reed, both of USDA ARS NCGR Corvallis, inspect plantlets stored in tissue culture. (photo by S. Ausmus, USDA ARS).

method for red raspberry. In addition, sets or dibs can be taken from species that tip root where canes touch the ground. Rubus genetic resources can be stored in tissue culture for secondary security backup (Fig. 16). Growth room conditions include light ranging from 10 to 1000 m mols1m2. Either warm or cool fluorescent bulbs produce the proper spectra for plant growth, although light requirements may vary for some genotypes. Air temperatures range from 22 to 28 C. Plantlets can be stored in semipermeable plastic bags for 1 to 3 years without transfer but must be evaluated three times a year for viability. Cultures can be stored up to 5 years under refrigerated

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Fig. 17. Dewars of liquid nitrogen that preserve genetic resources at the Dresden Gene Bank in Germany. (photo by M. Ho¨fer).

conditions. For long-term alternative storage, meristems isolated from tissue cultured plants can be cryopreserved in liquid nitrogen (Fig. 17). D. Pathogens and Safe International Plant Movement Raspberry germplasm conserved in ex situ collections is often requested by users across international borders. This movement of seeds and plants introduces risks of inadvertently moving pathogens along with the plants. Many destructive plant disease epidemics in other crops have resulted following the accidental introduction of pathogens along with plant materials to new geographic regions. Quarantines are the first line of defense against the international movement of pathogens. Most countries use quarantine regulations to control the movement of plants that potentially may be infected with specific economically important pathogens. For example, Rubus stunt phytoplasma, raspberry ringspot virus, and tomato blackring virus are known to infect raspberries in Europe, but these pathogens are not known to occur in North America. The presence of bacterial or fungal pathogens can often be determined visually by their signs or symptoms. However, viruses, phytoplasmas, and other viruslike organisms may be symptomless and not visible with a light microscope. Clonally propagated plants, such as raspberries, can accumulate viruses and viruslike pathogens (Fig. 18), which are passed on each time plants are

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Fig. 18. Leaf chlorosis in leaves of ‘Autumn Bliss’ as a result of raspberry bushy dwarf virus. (photo C. Kempler).

propagated. These pathogens can only be detected (Fig. 19) using specific laboratory or biological assays (Diekmann et al. 1994; Martin and Postman 1999). Virus indexing and virus elimination procedures are important activities at a gene bank involved in international plant exchange. Indexing procedures for raspberry viruses are regularly reviewed by the ISHS Working Group on Virus Diseases of Small Fruit Crops, and acceptable tests are recommended for use during plant

Fig. 19. Plant pathologist Robert Martin studies the results of serological tests on Rubus viruses. (photo by S. Ausmus, USDA ARS).

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introduction or certification (Martin 2004). Specific viruses that are significant to international movement of raspberry germplasm and their indexing protocols were summarized by Diekmann et al. (1994). Many DNA- and RNA-based assays using polymerase chain reaction (PCR) are available for pathogen detection. Although these techniques have increased sensitivity over older methods and often are the only tools available for detection of viruslike pathogens such as viroids and phytoplasmas, the serological-based enzyme linked immunosorbent assay (ELISA) is the most economical and most widely used laboratory procedure (Martin 1998). This serological test is normally performed using a 96-well plastic microtiter plate. In the ELISA, a virus-specific antibody is used to trap virus particles from pulverized leaf tissue. A second enzyme-labeled antibody is used to label and visualize trapped viruses (Clark and Adams 1977). Raspberry viruses that can be detected by ELISA include arabis mosaic, apple mosaic (rare), cherry leafroll, cherry rasp leaf (rare), cucumber mosaic (rare), raspberry bushy dwarf, raspberry ringspot, strawberry latent ringspot, tobacco ringspot, tobacco streak (¼black raspberry latent), tomato black ring, and tomato ringspot (Martin 2004). Serological tests like ELISA can only be used to detect well-characterized viruses for which antivirus antiserum is available. Electron microscopic examination of leaf dips and double-stranded RNA (dsRNA) analysis are often used to screen for uncharacterized viruses. Mechanical inoculation of herbaceous indicator plants or graft inoculation onto select Rubus species or clones will detect many raspberry viruses that are not well characterized. Indicator plants will produce characteristic symptoms in response to infection by certain viruses. Inoculation of Chenopodium quinoa with raspberry leaf tissue that has been ground in an appropriate buffer can detect apple mosaic, arabis mosaic, blackberry calico (¼wineberry latent), black raspberry necrosis, bramble yellow mosaic, cherry leaf roll, cherry rasp leaf, cucumber mosaic, raspberry bushy dwarf, raspberry ringspot, Rubus Chinese seed-borne, strawberry latent ringspot, tobacco ringspot, tobacco streak (¼black raspberry latent), tomato black ring, and tomato ringspot viruses (Martin 2004; Stace-Smith 1987). Grafting a leaflet from a candidate plant onto a young Rubus occidentalis indicator plant can detect black raspberry necrosis, raspberry leaf curl, raspberry mosaic (virus complex), and Rubus yellow net viruses. The raspberry cultivars ‘Malling Landmark’ and ‘Norfolk Giant’ can also be graftinoculated as indicator plants to differentiate specific viruses that are components of the raspberry mosaic complex (Martin 2004; StaceSmith 1987).

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Thermotherapy—growing infected plants at elevated temperatures for several weeks, followed by propagation of apical shoot tips—is the technique used to generate virus-free explants from virus-infected mother plants. A raspberry mother plant is grown for up to 3 weeks in a growth chamber heated to about 38 C. Afterward, meristem tips less than 1.0 mm long are excised and regenerated in vitro. Not all plants resulting from thermotherapy are pathogen free, and regenerated plants must be indexed to determine their virus status (Diekmann et al. 1994; Martin and Postman 1999). Once the investment is made to test raspberry plants for viruses and/or by applying therapy procedures to eliminate pathogens from infected plants, healthy plants must be protected from becoming reinfected. Gene banks and certification programs grow plants in screenhouses (Fig. 20) to prevent the entry of insect vectors. The most important vectors for raspberry viruses are aphids and nematodes. Aphid vectors must be excluded or controlled, and persons entering a screenhouse should be certain they are not carrying insects. Removal of flowers and exclusion of pollinators such as honeybees will prevent the movement of pollen-borne viruses such as raspberry bushy dwarf. Flower removal will also prevent fruit and seed development and possible clonal contamination by seedlings. Clones that index positive for viruses must be segregated from healthy or untested plants.

Fig. 20. Nuclear stock plants at SCRI. (photo by H.K. Hall).

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E. Germplasm Assessment and Publication of Data The major commercial taxa of raspberries share a considerable amount of interfertility. Rubus idaeus and R. strigosus are completely interfertile (Darrow 1920) and are commonly regarded as two subspecies of the same species. The cross of R: occidentalis  R: idaeus is successful only if R. occidentalis is used as the female parent, although bud pollination and heat treatment can help overcome this unilateral incompatibility (Hellman et al. 1982). Finn and Hancock (Finn 2008) reported 40 species in Idaeobatus and a few species in the Cylactis, Anoplobatus, Chamaemorus, Dalibardastrum, Malachobatus, and Rubus that have been used in raspberry breeding. The conservation of germplasm in modern clonal germplasm repositories is of critical importance for the future availability of a broad gene pool for raspberry breeding. However, this is of little value or consequence if only minimal information and data collection programs are available. Acquisition of new material must be balanced with detailed scientific evaluation of the plant material to assess pest and disease resistance (Fig. 21), adaptation, and environmental factors affecting growth. In addition, information of plant growth, morphology, and fruit quality should be available for researchers. This material should also be accessible for prebreeding or full breeding programs to be able to mine the genetics for data and for information on traits that are inherited recessively among the clones being investigated. The use of an interactive Web site or other electronic methods to store this information is another key element for accessibility and maximum use of the preserved genetic resources. F. Germplasm Needs as Delineated by Traits Growers and producers have specific needs that cannot currently be met with available cultivars. New germplasm may enable improvements in cultivars for these traits. Any collections that might meet these needs are highly desired:  Disease resistance, particularly for: Phytophthora root rot (Phytophthora fragariae var. rubi) and RBDV in raspberry  Pest resistance, particularly for: new biotypes of Amphorophora agathonica and A. idaei that overcome previous resistance; raspberry beetle (Byturus sp.), particularly in Europe, and sap beetles (Glischrochilus sp.); caneborers (Agrilus ruficollis and Oberea bimaculata) in eastern North America; grass grub (Costelytra zelandica White) in New Zealand

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Fig. 21. Oregon State University graduate research assistant Michael Dossett examines raspberry plants for aphids as part of data collection on germplasm accessions. (photo by S. Ausmus, USDA ARS).

 Environmental stress tolerance, particularly: to hot, humid climates, to drought, to high ultraviolet light intensity, and tolerance to cold winter environments  New sources of primocane fruiting characteristics  Adaptation to low-chill environments

III. BREEDING TECHNOLOGY A. Floral Biology Red raspberries and the species range of raspberry close relatives, the Idaeobati, are characterized by producing biennial canes that may fruit

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in the first year on primocane tips (primocane fruiting) or in the second year in new laterals that have grown on floricanes (floricane fruiting). Flower initiation occurs basipetally in apical and axial buds within canes and within inflorescences when canes reach physiological maturity, but they normally require chilling before growing on to form flowers and set fruit (Waldo 1934). The attainment of physiological maturity is under genetic control, and in high-chill floricane types, it does not occur until stimulated by environmental signals, including both temperature and day length (Williams 1960). In temperate conditions, these initiate flower buds in late autumn or the following spring after growth resumes (Dale and Daubeny 1987). Initiation of the torus, sepals, and stamens occurs soon after bud initials, but further development may be arrested until spring when meiosis takes place in the anthers, followed by meiosis in the gynoecium up to 4 weeks later (Daubeny 1996). However, in primocane-fruiting types, buds are free to continue to grow and will develop into flowers and set fruit, providing environmental conditions are conducive for growth. Primocane fruiting occurs basipetally, with older, more mature canes usually fruiting first and younger, later canes following, if the season permits. Primocanefruiting cultivars have been developed specifically to enhance this trait, with several sources of earliness and enhanced production being used to facilitate the development of new cultivars. Specific adaptation to primocane production in raspberries utilizes earlier arrival of physiological maturity, combined with the ability to break bud without chilling as long as growing conditions are suitable. When low- or no-chill conditions are encountered in floricane types, dormancy remains, and new growth will not occur until after chilling is received. In low-chill conditions, most primocane fruiting cultivars also cease growth after 2 to 3 years due to secondary dormancy, but the cultivar ‘Summit’ continues to cycle indefinitely when pruned to the ground after fruiting (H.K. Hall, pers. observ.). ‘Polana’ may also have potential to be cropped in this manner as unchilled plants are able to produce similar yields as chilled (Dale 2008). Many of the Idaeobati produce secondary or tertiary buds arranged in descending order below primary buds and differentiate very late, again in order of bud maturity. These buds may enable recovery from unseasonal bud break during a warm period in winter or from frost damage, and they offer potential for selection for higher yields through increased fruit numbers (Daubeny 1996; Keep 1969a). Flower types observed in raspberries include hermaphroditic, pistillate, staminate,

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and sterile. In cultivation, hermaphroditic is most common because strong selection pressure has been exerted for this trait (Jennings 1988). B. Hybridization Each parent used for crossing should be free of the common and resistance-breaking strains of RBDV and other pollen- and seed-borne viruses (Converse 1991; Daubeny 1986; Jennings and Jones 1989). RBDV is the most important virus problem with raspberries, causing poor seed set, poor fruit set, poor germination of seed, and yield losses. It also affects plant growth and ease of propagation. Elimination of RBDV-infected parents is a good way of limiting the spread of the virus and raising the health of seed populations (Daubeny 1996). Detection of the virus is possible by the use of ELISA, although care needs to be taken to reduce the likelihood of false positives when plate counters are used. False negatives also occur when virus load is not uniformly distributed within the plant. Crossing of raspberries may be done in the field or on potted plants under glass out of season to reduce work pressure when plants are flowering and fruiting in the field. Other advantages of performing crosses under protected culture include protection from cold- and wetweather conditions, reduced likelihood of plants becoming infected with RBDV or other viruses during or after crossing, and enhanced ability to intercross genotypes with different flowering and fruiting seasons. For making crosses in a greenhouse, quiescent plants are dug after growth has ceased and placed in cold storage (2 to 1 C) or potted (in a well-drained open potting mix) and placed in a screenhouse in cool conditions for chilling acquisition. After cold storage or chilling for 6 to 10 weeks, depending on the genotype, potted plants can be placed into a greenhouse at 14 to 21 C for flowering. Plants can be delayed for introduction into the greenhouse or put into cooler conditions to slow them down or brought in early or placed in warmer conditions to speed flower development. With most raspberries and deciduous Idaeobatus species, the time required for greenhouse flowering is 28 to 45 days. Some semi-evergreen and evergreen species may require a considerably longer period (Ourecky 1975a). They may be brought in earlier or used as seed parents utilizing stored pollen. With some programs it is considered essential to do crosses in a greenhouse when weather conditions may prevent or limit the ability to do crosses in the field. Other programs also may be advised to perform crosses in a greenhouse,

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as some years crosses have been lost due to adverse weather, frost, wind, rain, or hail. In the PARC-BC program and in other programs where weather conditions are kind for field crossing, it is quick and effective to get a team to complete crosses within a few days. Agriculture Canada use white glassine bags to cover flower clusters prior to anthesis on plants chosen as male parents. At the same time, flowers on chosen female parents that are in the plump bud stage yet not beginning to open are emasculated and also covered with bags. Care is to be taken that flowers that are emasculated are not too advanced as anthers may dehisce at an early stage, sometimes before flowers are open. Pollen from mother parents will cause fruits to set if self-pollination occurs, as most raspberry cultivars are fully self-fertile. Emasculation can be effected with a sharp scalpel, safety razor, or very sharp watchmaker’s forceps. Stray pollen grains are killed on hands and tools using 70% to 80% ethanol or isopropanol (not methylated spirits or methanol) before emasculations of different genotypes. Small flower buds are removed as they are difficult to emasculate and they would take too long to mature before becoming receptive for pollination. Emasculation is performed by making a cut around the base of the flower bud that removes the sepals, petals, and whorl of stamens, leaving behind the undamaged stem and the pistils borne on the receptacle. Two days after emasculation, open flowers are taken from bagged laterals of the designated male parents and brushed over the stigmatic surfaces on the emasculated mother flowers. This is repeated at 2-day intervals for up to 6 days (Daubeny 1996). Some genotypes produce copious quantities of nectar, which forms drops on flowers that can be a sticky problem when using flowers for pollination. This can be removed by touching the droplet with a match or sterilized instrument. When pollen is scarce, or if the paternal parent is going to finish flowering before female flowers are available, anthers can be collected and dried for pollen to be stored in a desiccator with calcium chloride (CaCl2) or silica gel. Ourecky (1975b) advocated the use of sulfuric acid in a shallow dish to facilitate rapid drying and dehiscing of larger quantities of anthers. Use of an incandescent light bulb 60 cm above an open petri dish of anthers or placement of the anthers in sunlight in a greenhouse also will promote drying of viable pollen (H.K. Hall, pers. observ.; Ourecky 1975a). Storage of pollen is possible in a sealed desiccator at 4 to 5 C with continuing viability for 4 or more weeks. Containers for storing of pollen may include polycarbonate, glass, or seamless metal salve tins; use of plastic petri dishes or vials is not advised as problems may be experienced with static electricity causing

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the pollen to stick to the plastic surface. Some problems may also be experienced with polycarbonate, but fogging the pollen for a moment with the breath can unstick the pollen from the vial surface. Application of pollen from the storage containers is possible by rubbing the stigmatic surfaces with the inside surface of the storage vessel or by the use of a camel-hair brush. Synthetic brushes give problems with static, similar to plastic storage containers. When stigmatic surfaces are receptive, the stigma opens out and exposes a sticky surface for pollination. After pollination has been successful, or the flowers no longer are receptive, the stigma and style starts to brown off very quickly, showing that further pollination is unnecessary. After pollination, bags are reapplied and kept on the lateral until fruit ripens. Large paperclips are effective in holding bags on the developing lateral, and if lateral attachment is weak, bags can be pinned to canes as well as covering the lateral. Neither brown nor plastic bags should be used as the former excludes light and the latter raises the temperature around the lateral (Daubeny 1996). If crossing is done in a protected environment, it is useful to have the crossing house enclosed with insect-proof screens to prevent access by bees or flies. In this situation, a greater number of flowers on a lateral can be used for pollination and crosses can be carried out over an extended period without bagging emasculated flowers. The environment is continually dry and pollinations are not affected by weather. In addition, seed germination may be better from seed produced in a protected environment as problems with poor pollination of ovules are reduced. Seed set and germination are also strongly influenced by the seed parent (Jennings 1971a,c). Thus it is wise to make reciprocal crosses when possible to be sure of producing seedlings of the desired genetic combination. C. Seed Extraction and Storage Mature fruit can be collected and stored in a refrigerator, not a freezer, as freezing reduces viability of seed quickly, until sufficient numbers have been harvested for seed extraction. It has been a common practice to extract seed extracted by using a laboratory blender to break up the fruit and remove pulp from seed by blending fruit in a pulp/water mixture at a slow to medium speed for a short time; 7 to 30 seconds is usually enough (Galletta 1983; Morrow et al. 1954). Firmer-fruited selections pose more difficulty for extraction of seed. For this reason, some programs now use an additional extraction aid by adding pectinase into the fruit/water mixture and incubating it

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overnight at 37 C or at room temperature for 2 to 3 days before blending. Once the fruit/water mixture has been blended, the mixture is poured into a container and washed with extra water. Pulp and unviable seeds can be poured off, and clean viable seeds remain in the bottom of the vessel. Seed is air dried on paper towels or in plastic cups kept at room temperature and stored in a refrigerator at 1 to 5 C until time for seed treatment and planting. If properly dried and stored, seeds of most Rubus species remain viable for several years when kept in cool storage (Ourecky 1975a). At the National Clonal Germplasm Repository at Corvallis, Oregon, Rubus seed is stored in aluminized plastic bags at 20 C, and the seed remains viable for extended periods of time (Fig. 14). D. Seed Treatment and Germination Pregermination treatment is necessary in most cases for prompt and uniform sprouting of seeds of most temperate and Arctic Rubus species (Ourecky 1975a). Usually this consists of a scarification treatment to make the seed permeable and able to swell, followed by stratification, which satisfies chill requirements needed for growth to occur (Daubeny 1996). Following these two treatments, seed can be sown on the surface of a light, open soil mix in a flat or pot and placed in moist, warm conditions with plenty of light to promote sprouting and growth of seedlings. Light is significant in the promotion of raspberry seed germination (Scott and Draper 1967). Moisture also is critical at this step, and germination is much reduced or stopped if seeds dry out even once (H.K. Hall, pers. observ.). Scarification usually consists of treatment with concentrated sulfuric acid (5–20 minutes for raspberry or Idaeobatus seed), followed by washing with water and sometimes abrasion to remove carbonized endocarp, then further scarification with calcium hypochlorite and an excess of calcium hydroxide for 1 week (Adams 1927; Heit 1967; Jennings and Tulloch 1965; Rose 1919; Scott and Ink 1957). Seed are then washed and stratified in bags of moist peat, sphagnum, vermiculite, or other moisture-absorbent medium at 4 C for 6 weeks or up to 10 weeks when the female parent is a high-chill genotype (Daubeny 1996; H.K. Hall, pers. observ.). Variations on this seed treatment protocol are reported from EMR, where acid treatment alone or bleach alone was used (Knight 2002b). Concentrated sulfuric acid (H2SO4) was applied to seeds for 90 minutes with containers plunged into an ice bath. Seeds were then washed under running water for 10 minutes and then stored in distilled water

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for 7 to 8 days, changing the water 2 to 3 times during this period. As an alternative seed were treated with 2.5% sodium hypochlorite (NaOCl) (50% household bleach) for 24 hr, then washed in running water and soaked in distilled water as above. Both treatments had variable results with the range of germination success from 1% to 78% with acid treatment and 1% to 90% with bleach. No comments were passed on the state of the seed in treatments with low germination percentages, but it appears likely that in some cases, each treatment could have been too severe. No comments were passed either on the number of seeds treated in each vessel or the volume of chemical used. Both are very important to the final result. In New Zealand, the method Jennings and Tulloch used was: 200 seeds were treated with 9 ml concentrated H2SO4 for 15 minutes in a polycarbonate vial that was immersed above the acid level in an ice bath. When the 15 minutes had elapsed, the seed was poured into a fine-mesh stainless steel sieve under running water and the seed was rubbed with a gloved finger (household rubber gloves) for 20 to 30 seconds, which removed much of the carbonized endocarp. Seed were immediately returned to the washed vial, and 15ml of Ca(OCl)2 saturated with Ca(OH)2 was added. Seed vials were then kept for 1 week in a coolstore before rinsing under running water and being placed into small zip-lock bags of moist sieved peat for 6 weeks’ cool storage at 4 C. Calcium hypochlorite solution was produced by adding 28.5g Ca(OCl)2 and 3 teaspoons Ca(OH)2 to each liter of solution. When seed numbers are low, it is essential to reduce the quantity of hypochlorite solution added to the vial; otherwise the seed will have the endocarp completely stripped away and be rendered inviable. After completing stratification, the peat/seed mixtures were mixed with dry river sand and sown on the surface of flats of a 50:50 peat/sand mix with added fertilizer. Care was taken to ensure that none of the flats dried out at all, as experience has shown that if a flat dries out once, even for a few hours, the seed will no longer germinate. Trays were placed in full light conditions in a greenhouse and given supplementary lighting to promote germination. Germination percentages were very high, usually over 75%. Dale and Jarvis (1983) reported that moist chilling could be eliminated if seed was treated immediately after harvest with concentrated sulfuric acid for 20 minutes and then immersed for 6 days in a solution of calcium hypochlorite, with excess calcium hydroxide, supplying 1% available chlorine. This method has been successfully used in the British Columbia breeding program (Daubeny 1996). Scarified seed was sown immediately after scarification onto a

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medium of peat moss, perlite, vermiculite, and a small amount of sand and covered lightly. Pots were placed in an incubator maintained at 25 C and a relative humidity of approximately 95% with a 16-hr day length. Germination began within 4 weeks (Daubeny 1996). In blackberries, use of chlorine bleach treatment alone has been used to scarify seed (Campbell et al. 1988). This method has also been used with raspberries at EMR, sometimes giving better seed germination than with the acid seed treatment protocol. Seed germination also appears to be promoted by timing the sowing of treated seed with normal springtime conditions, growth being promoted by rising temperatures and lengthening days. Other methods have been used for seed germination in raspberries and are applicable especially when seed numbers are low, including cutting or nicking seed coats before sowing or using in vitro methods to germinate seed. Nesme (1985) obtained over 90% germination after scarification by cutting endocarp, testa, and endosperm of seed. However, intact seeds and those only injured in the endocarp or endocarp and testa did not germinate unless the endosperm was damaged as well. Ke et al. (1985) used in vitro germination to obtain seedlings of crosses of raspberry with blackberry, and in New Zealand, similar techniques were used to germinate interspecific hybrids of raspberries from crosses between red and black raspberry (H.K. Hall, pers. observ.). Seeds were disinfected and cut in half before being placed on tissue culture medium under sterile conditions, and in 2 to 3 months, actively growing seedlings were potted from some crosses. In vitro germination of raspberries also has been used in the program of Galletta et al. (1986), where raspberries were successfully germinated, grown in tissue culture, grown to maturity, and resulted in selections in the field. E. Seedling Evaluation An effective raspberry breeder must understand genetics, plant physiology, biochemistry, statistics, botany, taxonomy, mutation biology, plant anatomy, entomology, plant pathology, and prophecy as well as being an observant horticulturalist or agronomist (J.N. Moore 1988). To Moore’s 1998 list we could now add molecular biology, engineering, and other disciplines. Today’s breeder has to be able to select the cultivars suited for the current industry and also anticipate changes to come all the way through the production and marketing chain to produce the cultivars of the future. Without doubt a breeder needs wisdom, insight, and understanding, not to

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mention tenacity to carry out an ambitious breeding program with often a token budget that has to be fought for and guarded from continual erosion. For efficiency, methods of managing seedling populations in a raspberry breeding program need to have four characteristics (Sherman and Lyrene 1983): 1. Rapid advance of plants from seed to fruiting to maximize genetic gain per year 2. Minimization of nongenetic variation among seedlings so that phenotypic differences will accurately reflect genotypic differences 3. Low cost per seedling so that a maximum number of seedlings can be grown 4. Provision for natural selection for favorable characters or for artificial screening for resistance to diseases, insects, and nematodes at a young stage Seedlings from crosses germinated in late winter/early spring grow well if provided with good growing conditions, and plants can be raised to be planted in the field in mid- to late spring. If weed control is good and seedlings are managed well, they can grow and produce primocane flowers and fruit before the end of the growing season, or produce a significant crop on floricanes the following spring/summer. If resources do not allow field management to be intensive during the first year, plants are better raised a little later in spring and grown in pots until planting in late autumn. When handled this way, larger established seedlings can be placed in the field and dormant plants can be oversprayed with some herbicide formulations for weed control. The plants will grow strongly during the next growing season and produce a very good primocane crop or floricane crop. In British Columbia, a common practice has been to prune the first year’s growth to the ground and to take the first crop on second-year canes. In northern Washington, with excellent management it was possible in one season to obtain good growth for fruiting the following summer. The warmer climates and longer growing seasons of California, Australia, and New Zealand make it much easier to produce good growth to enable a significant crop to be produced on first-year canes. At SCRI and at Geneva, New York, seedlings may take until the third year from seed to reach maturity, and assessments are often not possible until the third growing season in the field (Daubeny 1996). Planting density of red raspberries is not as close as possible with crown-forming black raspberry or blackberry seedling populations

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because seedlings need to be kept separate for propagation purposes after selections have been taken. For best results with seedlings, individual hills should be kept 1 to 1.3m apart, with row spacing 3 meters or more apart, especially when seedling vigor is high (Daubeny 1996). In New Zealand, research costs for growing seedlings have been reduced through grower provision of fields for seedling populations. Selection of seedlings for spinelessness, screening for pest and disease resistance, and use of molecular biology to screen for markers for resistance or economic traits also are valuable for reducing field seedling costs, either by reducing management or by rejecting seedlings that would have been culled later. Screening of seedlings for spinelessness is easy among seedling populations segregating for gene s, where spineless segregates are devoid of stalked glands around the edge of cotyledonary leaves and spiny plants are easily seen by the presence of glandular hairs. With good eyesight, glandular hairs can be seen with the naked eye; for those with less keen vision, hairs can be clearly seen in good light conditions with a hand lens. Spineless segregates can be planted into cell trays when they grow the first true leaves and spiny segregates discarded. Reaction to the aphid vectors of the raspberry mosaic virus complex, Amphorophora idaei (Borner) in Europe and Amphorophora agathonica Hottes in North America, is done as a primary screen in several breeding programs (Daubeny 1996). There has been good agreement between the reactions of young seedlings and the reactions of mature plants to the aphids (Daubeny 1986; Parker 1977). Screening for resistance to Verticillium wilt caused by Verticillium albo-atrum Reinke and Berth is reported by Fiola and Swartz (1989), but this protocol appears better suited to be used for screening selections of cultivar potential for resistance (Daubeny 1996). Preplant screening might also be possible with root lesion nematode (Pratylenchus penetrans (Cobb) Sher Allen); raspberry bud moth; Heterocrossa rubophaga Dugdale; Aphis idaei v. de G., and Aphis ribicola Oestl, the aphid vectors of raspberry vein chlorosis virus and raspberry leaf curl virus, respectively; two spotted spider mite (Tetranychus urticae Koch); powdery mildew (Sphaerotheca macularis (Fr.) Jackewski); raspberry leaf spot Sphaerulina rubi Demaree & M. S. Wilcox; and other leaf and cane diseases. Production of primocane-fruiting types in the first year of growth in the field is usually the best possible indicator of plant performance, providing the seedlings were planted early enough to allow development of full primocane-fruiting potential. Selection of outstanding primocane-fruiting clones is possible on the basis of fruit size and

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quality, vigor, plant habit, yield components, especially branching and potential yield, usually by the trained eye of the breeder. Floricane types can be selected for fruit quality and size as well as growth habit and yield components in the first fruiting season, but often selection for yield, vigor, cane numbers, plant health and mature growth cannot be evaluated until the second or third harvest season. Selection skill is becoming more difficult to acquire as many universities have dropped formal training programs in plant breeding and breeding programs in raspberries are becoming more secretive, not publishing or allowing rival breeding programs access to information that is essential for training unskilled breeders. Public breeding programs are being reduced, many are refusing rival programs access to genetics, and most are patenting or registering cultivars for plant protection under UPOV (Daubeny 1995b; Future of public breeding programs 2001). Since intentional improvement of raspberry cultivars was begun, breeders have chosen selections according to their individual artistic sense of fruit shape and appearance as well as their overall view of the plant. This has led to different style fruits being produced at different locations. More recently, artistic flair has been augmented by scientific training to assisted assessment for high quality and productive traits. Larger programs have teams of breeders and other specialists who examine the best selections before advancing elite lines to the next stage of evaluation. Nevertheless, evaluation by eye, even by a team of specialists, may not produce a perfect or even a good assessment of a selection. In strawberry, visual assessments by breeders also have given imperfect pictures of elite material, but this was overcome by evaluating seedlings as part of a designed genetic experiment as well as by using intensive methods of gathering data on the seedling progenies, including fruit harvest of individual seedlings (Shaw and Luby 2005). This approach has also been used in raspberry breeding, and it resulted in the identification of elite individual selections that were not recognized by members of the breeding team before data was analyzed (Connor et al. 2005a,b; H.K. Hall, pers. observ.). A particular selection of significance from these seedling populations was a veryhigh-yielding clone, which fruited over a long harvest season and was not identified as a selection by visual means. This has subsequently been used in further breeding, transferring higher yield potential into seedling progenies. There is little doubt that this approach will result in greater gains by future raspberry breeders, especially when adaptations are made to machine harvesters allowing real-time data collection of yields and

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collection of separate fruit samples of individual seedlings throughout large seedling blocks. The technology for this exists but has not yet been put together in an operating package for assessment of raspberry seedling populations. Unless the genetics of a particular trait are known, it is difficult to predict the size of population needed to achieve a specific objective (Ourecky 1975a). When breeding behavior is not known, a progeny of 100 to 200 seedlings generally gives the potential of a specific combination. However, larger population sizes are advisable if crosses involve parents that are genetically diverse, with backgrounds from different species (Daubeny 1996) or with specific traits to introgress into locally adapted germplasm. The amounts of space and labor available may be overriding limitations, especially since budgets for breeding have diminished significantly in recent years, with other specialized skill areas taking up resources that used to be devoted to breeding (Ourecky 1975a; Sjulin 2003). Seedling numbers in breeding populations of raspberries vary considerably from program to program, depending on availability of land, labor, materials, and supplies to maintain plants over a period of 2 to 4 years while selection for horticultural traits is made (Daubeny 1996). Current breeding programs plant as few as 700 seedlings every third or fourth year, to as many as 30,000 planted into the field per year (Daubeny 1996; Finn et al. 2008; H.K. Hall, pers. observ.). In Russia, large numbers of seedlings were grown in the mid-1970s (Kichina 1976), but this progress does not appear to have been sustained through the political upheavals that have been experienced there in the last decade. When selections chosen for advancement to the next stage of evaluation and for becoming parents of the next generation of seeding populations have been propagated and removed from the seedling field, remaining seedlings should be removed as soon as possible (Daubeny 1996). In the British Columbia program, roots are taken from selected plants during the fall, and after surface sterilization, they are propagated by root cuttings. Other programs dig canes or take plant material for initiation into tissue culture or use some combination of these three protocols with the different selections from the program according to the priority placed on them by the breeder and the resources available. Leaf tissue of selections in the PARC-BC program is tested for RBDV by ELISA. If a positive reaction is obtained, the selection is discarded. Selections that become infected after flowering in the field for only 1 year in BC are considered ultra-susceptible to natural pollen infection from the virus and to be a risk if grown on a large scale (Daubeny 1996).

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F. Selection Evaluation In the HRNZ raspberry breeding program, plants pass through five stages to be released as commercial cultivars (Hall and Stephens 2006): Stage I. Seedling evaluation in a field seedling block Stage II. Preliminary observation plots (1–2 plants per plot, 1–2 replicates) Stage III. Replicated trials of elite clones (4–7 plants per plot, 3–4 replicates) Stage IV. Larger- scale plots and grower trials (10-m plots up to 1 ha) Stage V. Registration for plant patent and plant variety rights This process establishes the potential for commercial success of individual selections and gives growing experience to base management recommendations for cultivar release. In addition, growers and researchers become aware of pitfalls with each selection that could result in obstacles for commercial success (Hall and Stephens 2006). At each stage, standards were included according to the current commercial cultivars and the advanced selections most likely to be released in future. In the PARC-BC program, selections of cultivar potential are bulked to 9 disease-free plants for trialing (3 plots of 3 plants), and plants retained for breeding purposes are placed in a single 3-plant plot (Daubeny 1996). Cultivar standards are included there in trials on a similar basis to the HRNZ program, with a mixture of process and fresh commercial standards along with the latest new cultivar releases. In Britain, Meiosis (an independent nursery body set up to introduce new cultivars in the United Kingdom and to fund research) manages trials of promising selections from EMR and SCRI and around the world. A similar trialing system is also operated by Hargreaves Plants, the largest commercial raspberry nursery in Britain, assessing elite selections from many programs internationally. Selections are placed in primocanefruiting or floricane-fruiting grower observation trials each year, and every 5 to 6 years the most promising selections are placed in replicated trials funded by the Horticulture Development Council (HDC) (Knight 2002a). Depending on the mode of fruiting (primocane or floricane), location, and speed of establishment of plots, horticultural evaluation of selections compared with standards is begun at the earliest at the end of the first growing season for primocane-fruiting types. In floricanefruiting types, evaluations usually begin in the second or third year of

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growth, but in a cool, short season location assessment may begin in the fourth year. If sufficient labor is available, plots will be harvested at 2- to 5-day intervals for the duration of the production period. This may be as many as 14 times for floricane-fruiting clones or sometimes 20 or more times for primocane-fruiting types. In addition to yield, data are collected on fruit size and fruit rots at harvest, and fruit is evaluated for anthocyanin concentration, color, ease of harvest, flavor, firmness, fresh and process market suitability, shelf life, soluble solids, titratable acidity, and reactions to postharvest fruit rots. For the fresh market, floricane-fruiting selections need to outperform ‘Tulameen’ (Plates 2G and 6C) for firmness; nondarkening bright red color; appearance; light, fresh and sweet flavor; shelf life; and productivity; or equal to ‘Tulameen’ and produce in an earlier or later harvest season. Primocane-season fresh-market types also have ‘Tulameen’ as a minimum standard for fruit quality and should also achieve similar or better yields than long-cane ‘Tulameen’. For process cultivars, fruit firmness and ease of harvest are essential. Color should be dark, similar to ‘Meeker’ and ‘Willamette’, the flavor rich and moderately acidic, anthocyanin levels and sugars high, and be suitable for individually quick frozen (IQF) fruit, dessert packs, juice, jam, and other processing applications (Daubeny 1996). Some tolerance to light fruit color is currently extended to process cultivars for IQF production, but this may not last when high-quality and high-yielding IQF cultivars with darker fruit color become available. If labor is not available for harvest, good estimates of yield can be made (Daubeny et al. 1986), but if yields are estimated, postharvest fruit assessments are not possible. Even if samples are obtained for evaluations, they may not be typical of fruit harvested at regular intervals because of the greater likelihood of variable ripeness and exposure to fruit rot organisms. This factor also may be an issue even when a full harvest program is practiced, as fruit often are overripe for the purposes of shelf life and fresh market evaluations. Horticultural evaluations also include the aspects of growth habit. The ideal habit has strongly attached, mid-length, semi-upright (lateral angle 30 –80 from vertical), outstretched laterals on sturdy, spine-free upright canes. Fruits are spaced at relatively wide intervals along laterals and not bunched, either at tips or nodes, and easily visible for hand picking. An open habit with outstretched laterals promotes a natural environment limiting the spread of Botrytis fruit rots (Daubeny 1996; Daubeny and Pepin 1981; H.K. Hall, pers. observ.). Sufficient, but not excessive, numbers of vigorous primocanes need to be produced for propagation, cane replacement, and production of an abundant crop.

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Moderate cane vigor and numbers are extremely important, especially in locations with good growing conditions and management. Overabundant growth induces long internode lengths, reduction in fruiting nodes per cane if pruned off at a standard height, and ongoing management costs to reduce cane numbers and length. Restrictions on the availability of spray chemicals for cane vigor control have caused difficulties for growers and were directly responsible for the demise of the SCRI cultivar ‘Glen Clova’ (Glen Clova casualty of Dinoseb ban 1986; Government to help Glen Clova growers replant 1988; Howard et al. 1989; Lawson and Wiseman 1989). In addition, growing of raspberries in a region prone to spring and summer rainfall poses weather restrictions on cane growth control as most chemicals need to be applied to dry plants in fine weather (Crandall and Adams 1979). In colder temperate regions, winter-hardiness is a primary concern in the evaluation of new selections of cultivar potential. Selection for hardiness usually depends on weather fluctuations and the arrival of unusually cold ‘‘test winters.’’ However, winter damage on different clones may vary according to acclimation, timing of the temperature shock, and weather before the cold period arrives (Daubeny 1987a). For dependable winter-hardiness, especially in areas where periods of warmer weather occur during winter, selection for early dormancy and late bud break is likely to achieve good results (Daubeny 1996). Lack of winter chill can limit production of floricane-fruiting types, due to poor bud break and lateral formation. This occurs in regions with low-chill climates, such as central coastal California, Mexico, New Zealand and southeastern Australia. For dual-cropping cultivars grown in the two-crop production system in California, advantage is taken from floricane raspberries predisposition to have their best budbreak in the first production season. However, for floricane-cropping cultivars grown in the normal annual production system, bud break needs to continue to be uniform and high for the second and subsequent production seasons; it cannot rely only on the ability of plants to exhibit better bud break in their first year of production. In British Columbia and other northern hemisphere cool temperate breeding programs, aphid infestations are monitored in the planting and subsequent seasons on all selections and cultivars in the field. This is an effective process to ensure that seedlings classed as resistant as juvenile seedlings are actually resistant in the field as mature plants. It also helps the breeder to be vigilant for the presence of resistance-breaking aphid biotypes, providing natural infestations are relatively high and well distributed throughout trial plantings (Daubeny 1996).

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During the second and subsequent years in the field, each selection is examined for disease symptoms, including crown gall (Agrobacterium tumefaciens [Smith & Towns] Conn.), cane Botrytis (B. cinerea), spur blight (Didymella applanata [Niessl] Sacc.), anthracnose or cane spot (Elsinoe veneta Burkh. Jenk.), cane blight (Leptosphaeria coniothyrium [Fuckel] Sacc.), powdery mildew (Sphaerotheca macularis (Fr.) Jackewski), yellow rust (¼cane rust, western yellow rust) (Phragmidium rubi-idaei (DC.) P. Karst.), late leaf rust (Pucciniastrum americanum [Farl.] Arth.), leaf spot (Sphaerulina rubi Dem & Wilc.), and bacterial blight (Pseudomonas syringae van Hall). At the same time, examinations are made for insect, mite, and nematode damage, possibly including aphids (Fig. 26) (Aphis idaei v. d. Goot, Aphis ribicola Oestlund, Amphorophora agathonica Hottes or Amphorophora idaei Boern.); eastern raspberry fruit worm (Byturus rubi Barber); raspberry cane beetle (Byturus tomentosus [De Geer.]); raspberry bud moth (Heterocrossa adreptella Walker); black vine weevil (Otiorhynchus sulcatus [F.]) and other weevils; grass grub (Costelytra zealandica [White]); and various nematodes (Pratylenchus penetrans [Cobb 1917] Chitwood and Oteifa 1952, Xiphinema americanum Cobb, and Longidorus elongans [de Man]). When RBDV pressure is high, plants can be screened for natural infection each year. It is important to cull plants that rapidly acquire the virus in these conditions because they will have a limited commercial life unless used in long-cane or dual-crop production systems. When the resistance breaking strain (RB) of RBDV is not present, selection for RBDV resistance through gene Bu is possible. When virus pressure is low, a benign strain of non-RB RBDV is present, or a selection has multigene resistance to quick infection with the virus, plants can escape infection with RBDV for an extended period, as found with ‘Glen Moy’ and the New Zealand cultivar ‘Kaituna’. Breeding programs consider the important pests and diseases for their region. Others may be nonexistent, unimportant because of cultural methods used, or of minor importance in their locality so they do not warrant investment of resources to combat them. However, as programs become larger and multinational in their outlook, it will be important to consider pests and diseases for the target markets outside of their own region. In the past, this has not been possible in the absence of natural infection, unless the chance use of resistant parents has given rise to resistant selections among the progenies. In some, cases it may be possible to select for resistance to a related disease that is present that could be expected to give resistance to the major disease from that genus present in the target market. In New Zealand,

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Phytophthora fragariae var. rubi is not present but selection for resistance to P. citrophthora can be expected to give resistance to the highly pathogenic relative present in the United States, Canada, and Europe. When molecular biology techniques to screen for resistance in seedlings by marker assisted selection (MAS) are available, screening may be possible in locations where the disease is absent (Weber et al. 2008a). Even where the disease is present, MAS promises to speed up identification of resistant segregants and reduce the resources invested in breeding by eliminating the growing of susceptible segregants in the field. MAS will also eliminate the spread of the disease into breeding fields on the roots of resistant segregants identified by standard inoculation techniques. With most diseases and pests, the breeder relies on natural infection for selection of resistance or tolerance, but inoculation for cane blight, cane Botrytis, and spur blight has been used at SCRI (H.K. Hall, pers. observ.). At EMR, resistance to cane spot and powdery mildew has been evaluated through the use of inoculation techniques (Keep 1989). At Puyallup, the WSU program used high-RBDV inoculum pressure in an intensive potted plant trial to identify resistant selections and cultivars. Gene H controlling cane hairiness or pubescence has been considered for selection at EMR and SCRI because of its association with resistance to cane blight, cane Botrytis, and spur blight (Jennings 1988; Keep 1989). However, gene H was also found to be associated with reduced resistance to cane spot, powdery mildew, and yellow rust (Jennings and Brydon 1989a; Jennings and McGregor 1988). The action of the gene is unknown, but it may be caused by pleiotropic effects, be linked with genes controlling reactions to these diseases, or the presence of hairs may modify the microenvironment to make infection less or more likely. Selection for plants homozygous for gene s, producing spine-free canes, and the dominant gene B for waxy bloom on canes can also reduce spur blight incidence but, like gene H, the actions of these genes are unknown (Jennings 1988). Combining genes s, B, and H produces increased levels of resistance (Daubeny 1996). Selection for root rot (Phytophthora fragariae var. rubi Wilcox & Duncan) (Pfr) resistance is becoming more important in raspberry breeding programs worldwide as devastating outbreaks of root rot can almost wipe out an industry, as experienced in Australia in 1994 to 1996 (Daubeny 2002b; Graham and Smith 2002; McGregor and Franz 2002). In the Pacific Northwest, one of the factors that led to the replacement of ‘Willamette’ with ‘Meeker’ was the susceptibility to Pfr, but in some locations this resistance is failing (P.P. Moore and

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Daubeny 1993). Few breeding programs have trial plots for doing infield evaluations for Pfr resistance. In most cases where trial areas have become infected, the programs have shifted to new clean soil for evaluation of seedlings and trialing selections. A significant exception to this is the WSU breeding program based at Farm 5 at Puyallup, where the trial site soils are highly infected with Pfr and only the most resistant selections survive. Over the last 37 years, trials at Puyallup have screened many species, selections, and cultivars from WSU breeding, from the PARC-BC program in British Columbia, and from around the world (Barritt 1970; Barritt et al. 1981; Bristow et al. 1988). Good sources of Pfr resistance have been found in R. idaeus, R. illecebrosus, R. strigosus, R. parvifolius, R. parviflorus, R. spectabilis, and R. sumatranus, especially when the source accession has been selected from a wet site (Bristow et al. 1988). This trial site acts as an excellent secondary screen to selections chosen for potential Pfr resistance. Pfr-resistant selections in current breeding programs have been produced from R. strigosus (‘Latham’ plus at least four other resistant R. strigosus accessions), R. idaeus (‘Asker’ ¼ ‘Winkler’s Sa¨mling’), R. spectabilis and R. sumatranus. Secondary screening protocols are also available for determining tolerance or resistance to black vine weevil, cane midge, crown gall, and Eastern raspberry fruit worm (Daubeny 1986; Keep 1989). Resistance to two-spotted mite is also becoming important for selection in raspberries, as this pest is more prevalent when plants are grown in warmer and drier environments, especially under protection and in warm temperate and subtropical conditions. In British Columbia, selections that appear superior to standard cultivars after more than 3 years of trialing in first test plots are propagated for more extensive trials, with local growers and at research sites locally and with other research programs in North America and overseas (Daubeny 1996). Research sites have been chosen to represent as many environments as possible so that environmental resilience of the selection and its commercial potential can be determined. A selection performing well at a distant site is propagated for grower trials in that region, and sometimes the selection is released as a cultivar on the basis of that performance, even when it is not commercially promising in British Columbia. For example, ‘Algonquin’ was released because of its performance in eastern Canada and Denmark (Daubeny et al. 1991). During the evaluation process, plants for distribution as dormant canes, root cuttings, and tissue-cultured propagules need to be kept clean of viruses as well as other diseases and pests. This is best done by generating high-health nuclear stock that is kept free of pathogens in an

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insect-proof screenhouse (Fig. 20) (Dolan and Barker 2008). Highhealth stock is maintained for distribution to certified propagators if the selection warrants release as a commercial cultivar (Daubeny 1996). Movement of plant material from country to country is much easier when health status has been well documented through a testing program and when plants have been placed in tissue culture. A well-organized breeding program evaluates all selections each year to make decisions to advance them to the next level of assessment, retain them for breeding, or discard them. If a selection has already been used for breeding, it should automatically be retained until progenies are evaluated so that if it has superior performance, it can be used again for breeding. If the selection is sufficiently promising, a decision can be made to fast track it to a higher level of assessment as well as the next level, for example, directly from Stage I to Stage IV, using tissue culture to bulk the plants. All such fast-track movements increase the risk to grower and nursery if the plant is quickly passed through to commercialization, but if the selection is sufficiently superior it will pay dividends. Even if a selection is fast tracked, evaluations should give sufficient information to make reliable decisions on registration for plant patents or plant variety rights and commercial release. In addition, information should be available for a growing protocol to be tailored for the new cultivar in commercial cultivation. G. Privatization, Plant Patent/PVR Descriptions and Strategies Intellectual property protection, globalization, and pressure on public budgets in many industrialized countries have shifted the balance of plant breeding activity from the public to the private sector (Heisey et al. 2001). In raspberry breeding, most of the activity is in industrialized countries. Much of the historical raspberry breeding has been carried out there, although in recent years, there has been increased activity in some of the less industrialized nations. Since the 1990s, a devastating wave of budget cuts, new innovations, restructurings, and program closures has seen the demise of many small, publicly funded raspberry breeding programs, with the accompanying loss of much of the research in allied or supporting fields and the redirection of funds to the protection of intellectual property rights in the larger programs (Daubeny 1995b). In some cases, support programs in biochemistry or molecular biology have been elevated to become programs in their own right, in spite of the removal of the breeding programs that they were developed to support.

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The place of horticulture as a science and horticultural plant breeding programs has been eroded in universities. Many scientists prefer to be known as geneticists, molecular biologists, botanists, or specialists in other areas. Horticultural plant breeding has suffered significantly in the last 30 years, especially in minor crops such as raspberry. As public funding for agricultural research has diminished, scientists have been required either to curtail their research efforts or to seek grant funds to continue their programs (J.N. Moore 1988). At the same time, leadership in research organizations has diminished and managers have taken over at all levels of authority, requiring much greater justification of the work that has been done or is to be done, particularly in validating expenditure. The overall result has been that the close relationship between scientists and industry has been eroded, and efforts toward solving industry problems have diminished (J.N. Moore 1988). The number of university programs in horticulture has been greatly reduced. At secondary school level, horticulture has come to be regarded as the course for nonacademics who may end up making their living working for local horticulture industries (picking, pruning, training, etc). Numbers of plant breeding graduates available for research positions both in the public and private sectors are limited, and highly trained breeders from public programs are being encouraged into private sector programs, to be replaced in many cases by less trained support staff. In other breeding programs, retirement or death of the specialist has led to immediate closure of the program and culling or loss of much valuable germplasm. Public sector investment in raspberry breeding may have benefits to society that the private sector’s activities may not. For example, it may foster greater sharing of information and more work on traits of plant cultivars, such as accumulating genetic improvements from wild species that may take 20 to 40 years to show significant benefits in terms of cultivar outputs, as has been achieved in the EMR breeding program several times during the life of that program. Further public investments in North America were directed at developing cold-hardy types in Manitoba and in Wyoming, both programs that have now ceased. Government investment in development of new berry varieties leading to increased berry consumption can also significantly impact public health, especially where the crop is newly introduced. Cultivation is increasing in areas where European and North American red raspberries are not naturally adapted, mainly through the influence of public breeding programs over decades of investment. In Finland, a government initiative for increasing berry consumption reduced problems in the population with heart disease

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and other ailments. With the use of modern chemistry, there is great potential for improving the nutrition of the population in temperate regions worldwide, especially those living in urban environments. Government investment is also important in changing the use and importance of the crop through investment in advertising through television and magazines as well as through food articles and restaurant promotions. Remaining public sector raspberry breeding programs in North America and Europe almost all register their new cultivars for plant patent and/or plant variety rights under the International Union for the Protection of new Varieties of Plants (UPOV), Geneva, Switzerland. While the rewards for successful cultivars are high, many selections elevated to cultivar status do not succeed and make a net loss after investment to register them for worldwide protection, payment of personnel, legal fees, registration fees, and upkeep fees to maintain protection. In many cases, payment for PVR and plant patent protection comes from the same pool of funds that support the breeding program, so overall monies available for breeding may be reduced by pursuit of intellectual property protection. In the private sector, quality of science is at times compromised in the clamor for production of an economically successful cultivar. At least one private program has spread virus infection and other diseases to parts of the world that were clean (L.L. Da Fonseca, pers. comm.). DSA seems to have found the recipe for success for a private raspberry breeding program. DSA does not sell cultivars but retains them and handles the cultivars and fruit production all the way from seedling selection through to supermarkets and other wholesale and retail outlets. Expansion worldwide has been made through agreements with local organizations that assist with the maintaining of intellectual property and manage sales of fruit. Royalties in that program are based on fruit production, bringing a guaranteed return each year back to the research program and to the owners. Several other large companies with production and marketing operations for red raspberry production are developing new cultivars and managing exclusive genetics for the future of their operation. There are several dangers inherent in the current trend to privatization and development of exclusive genetics for a commercial raspberry operation:  Programs developing cultivars and genetics for less productive marginal environments and areas with a smaller population base are being closed.

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 Longer-term objectives, including the use of novel genetics and wild species to improve the germplasm base of raspberries, are being eliminated from breeding programs as they are not economic steps toward the development of new cultivars in current production regions.  Exchange of genetics between programs is reduced, and a few companies are attempting to tie up the genetics from most of the available world raspberry breeding programs.  New cultivars have to be kept from release until trialed in a wide range of environments so that PVR and plant patent applications are not compromised by time constraints for registration in the United States or other countries. This results in a slowing of progress in new cultivar development and is likely to have economic impact on growers and marketers who cannot plant the new types before all legislative hurdles have been crossed. In contrast, if the breeder makes a public disclosure or a sale before international evaluation is carried out, only one year is allowed for filing for protection under United States Plant Patent (USPP). Under UPOV regulations, protection must be filed for within 4–6 years of the first commercialization (Clark et al. 2007). Failure to carry out protection across all these potential growing regions can result in loss of protection in those regions or, at best, needless expenditure on plant protection if the cultivar performance is not satisfactory to the region.  To address this issue, both the UPOV and USPP legislation could easily extend the time available for application for and registration of new cultivars for protection under the laws of different countries. Of particular value would be the establishment of a single legislative body responsible for worldwide registration for plant protection, with reference standard collections kept in multiple locations around the world. Under this body a single fee would be required for international registration, and a database similar to the USPP database would be available so that descriptions of cultivars would be available for all.  Red raspberries are an outcrossing species that perform best when approaching maximum heterozygosity. An examination of the western world’s red raspberry cultivar releases over the last 20 years reveals that 46% of these had a cultivar or selection from another program as one of its parents. In the second generation, 63% had at least one foreign parent; and in the third generation, this number rose to 72%. A further 12% of the selections had unknown or undisclosed origin, but it is likely that they also were

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derived in part from other programs. Thus over 70% and possibly as much as 85% of new cultivar releases have been produced from crosses involving material from outside their own breeding program over the previous three generations of improvement. It appears likely that reduced exchange of plant material could result in considerable reductions in genetic improvement in most of the raspberry breeding programs worldwide.  Large-scale commercial development of raspberries based on a company’s genetics and a reduction in the diversity of cultivars available in the marketplace increases the risk of a single disease or pest making an economic impact on production and sales in the marketplace. Under UPOV, the conditions for granting Plant Variety Rights Protection are:  Novelty. A raspberry variety must not, for more than one year, have been offered for sale or marketed with the consent of the breeder in the country of registration, nor for more than 4–6 years in any other country. Therefore, novelty arises in a commercial sense, not in the sense that the plant is necessarily a ‘‘new’’ development.  Distinctness. The variety must be clearly distinguishable by one or more important characteristics from any other variety whose existence is a matter of common knowledge. (It is or has been the subject of a plant variety right in any country, it is or has been listed in an official register of varieties in any county or that an application for PVR or entrance to an official list is in progress, provided they are granted.)  Stability. The plant must be stable in its essential characteristics, which are the same after each cycle of propagation.  Denomination. The variety must be given a denomination or approved name enabling it to be identified (DEFRA 2005; IPAustralia 2006; Plant variety rights protection in New Zealand 3002). Plant protection will be granted only when the government agency responsible for the granting of rights has determined that the variety fulfills these criteria. The grant of a PVR under the original UPOV (www.upov.int/) charter does not prevent others from:  Growing or using a protected variety for noncommercial purposes

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 Using the plants or parts of the protected variety for human consumption or other nonpropagating purposes  Using a protected variety for the purpose of plant breeding  Using a protected variety for experimental purposes Because the PVR regulations are written separately in each country, the specific wording of regulations in each country varies. In addition, legislation prevents the owner of a variety from obtaining a plant patent in some countries, yet in others separate plant patents are possible and even advised. Protection of a cultivar by PVR is possible to defend in court in some countries; in others it is very difficult, because of differences in legislation. Each country that protects plant variety rights under UPOV/PVR/ PBR regulations requires the submission of applications, technical questionnaires, and objective descriptions, often set out as forms. These forms may be requested from the PVR/PBR office; in some countries they are published on Web sites. With the United States Plant Patents Office, objective description forms are not available, and the required descriptors changes with time and with examiner. Some countries make cultivar descriptions available online but they are not necessarily available as images, as with the USPP Web site. Plant patents in the United States are less formal than the technical questionnaires or objective descriptions under UPOV. However, there has been a considerable increase in information presented for plant patent registration since 1990. This is a double-edged sword for the owner of the patent. On one hand, it will make defending a case where a cultivar has been stolen easier, but on the other hand, it may make it easier for anyone seeking to challenge a patent to proceed, especially if any information is doubtful or wording is incorrect. Interpretation of USPP law by some parties suggests that it may protect the patent owner from the use of his or her genetics by others for breeding, but at this stage this interpretation has not been upheld legally (Clark et al. 2007). However, it is unlikely that this will be possible as an examination of the English in the relevant section in the amended USPP regulations shows a clear connection between the protection and vegetative propagation. Thus the patents do not prevent anyone from using a cultivar for breeding. The current practice of breeders is to continue to use patented cultivars as breeding parents when they are available. Nevertheless, any breeder is free to purchase fruit from a supermarket or other sales outlet to access germplasm. In spite of problems with inbreeding depression, it will be possible to select useful parents for breeding out of the first or second generation of seedlings. In many

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cases, restriction of use of patented cultivars is through honorable or formal agreements between cooperating parties, although formality is becoming more important. Protection of a cultivar limits propagation to those granted permission to do so by the owner or the holder of the rights in that territory. Agreements are negotiated between the rights holder and the propagator for propagation to legally occur. They may be exclusive to a nursery or nonexclusive, allowing multiple propagators for the cultivar. Licensing fees can range from hundreds to tens of thousands of U.S. dollars, depending on the potential popularity of the cultivar, the value of the owner’s intellectual property, territory size, and competition. Many of the cultivars of raspberries given protection under plant variety rights, plant breeder’s rights, and U.S. plant patents have been marketed with royalties on plant sales returning an income to the breeder or the breeder’s employer. However, DSA-Sweetbriar has throughout its history licensed cultivars to growers without selling the plant material and has collected a royalty on fruit sales. This has worked very effectively as the sale of fruit has been managed within the organization. Where the company is licensing material outside of the United States, it is working with vertically integrated organizations that handle both fruit growing and marketing. The practice of royalty collection on fruit sales offers greater returns to the breeder from a cultivar than from plant-based royalties. This practice is likely to increase in future (D.L. Jennings, pers. comm.). Trademark protection of raspberries has not been a common practice but it may be used more effectively in the future, especially when genetics from a breeding program has made marked advances over the competition and when the protection is envisaged to last more than the maximum of 20 years for USPP or up to 30 years under UPOV. In addition, the use of a trademark offers potential for developing an ongoing marque that can be used for generations of new cultivars from a breeding, growing, and marketing organization. Some major raspberry cultivars, such as ‘Meeker’, ‘Heritage’, and ‘Autumn Bliss’, have outlived the lifetime of protection for USPP yet they remain significant cultivars in some parts of the world. It is likely that other cultivars will also show extended life in the future and will be worth the effort of obtaining ongoing protection with a trademark. If simultaneous testing is carried out in several international locations, then the evaluation period may be extended by up to 5 years so that registration for intellectual property rights can be carried out at each location within a 1- to 4-year period without risking the loss of rights and income from the cultivar. Another commercial factor that

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may extend the time from hybridization to release includes waiting until the plant protection on a previous cultivar expires before introducing the new replacement. If there is a significant issue, commercially with an existing cultivar, however—pest, disease, quality problems, or increased competition from a rival cultivar—then the release of a new cultivar may be accelerated. H. Cultivar Release and Commercialization The beginnings of raspberry breeding were in the 19th century when amateurs sought to produce new cultivars for home gardeners, prior to the establishment of commercial production in most parts of the world. Since that time, the majority of raspberry breeding worldwide has focused on the development of new cultivars for the commercial industry in the area to support local growers or establish an industry. However, a small but significant raspberry breeding component has supplied new cultivars for home gardeners and hobby growers. When there were no commercial ties to cultivars the best selections became available for all, but since the establishment of commercialization, secondary selections, or selections with commercial flaws, have been made available to nurseries for home garden, ornamental, or hobby gardener sales. In Germany, for example, one breeder is developing cultivars only for the home garden or ornamental market (H.K. Hall, pers. observ.). In the United Kingdom, ‘Joan J’ sales are almost exclusively to amateur growers; there are no commercial plots of ‘Joan J’ because it does not suit the supermarkets. It darkens quickly and lacks shelf life but is the best for flavor and fruit size (D.L. Jennings, pers. comm.). It is gaining popularity in California, perhaps because the fruits hold up better there, and was reported to be the star attraction at a growers’ meeting in Washington (D.L. Jennings, pers. comm.). The time from hybridization to cultivar release of new raspberry cultivar is usually around 15 years but ranges from 6 to 40 years with the cultivars listed in the ‘‘Brooks and Olmo’’ lists of raspberry cultivars. It can include up to 4 years for seedlings to be: germinated; screened for spinelessness, aphid, or Phytophthora resistance; planted in the field and grown to maturity. Then it can include 1 to 6 years for selection, 2 to 5 years for evaluation of selections, followed by 2 to 5 years of advanced selection testing. Collection of data for intellectual property rights (plant variety rights, plant breeders rights, plant patents and trade marking) obtaining protection from the relevant authorities and bulking of plant material also needs to be carried out before commercial release.

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Many programs carry out DNA fingerprinting in a further effort to reliably identify a cultivar, both for plant protection authorities and to check the identity of cultivars throughout the propagation pathway. Newer techniques at the Rubus Germplasm Repository in Corvallis may also enable a cultivar to be assessed for potentially damaging sports occurring during propagation (N. Bassil, pers. comm.). DNA technology has the potential to eliminate considerable losses for the breeder, nurseryman, and grower, especially if it eliminates mistakes or mutations that result in the production of thousands of atypical plants in tissue culture and in the field. Before the official release of a new cultivar, it is important that propagators produce quantities of high-health, virus-free plant material so that early demand can be filled and the first years of protection are not wasted for bulk of plant material to meet initial sales demand. Production of ample quantities of high-health plants can fulfill a high demand from growers and effective rollout of a new cultivar without costly failures to supply orders and industry dissatisfaction. An outstanding cultivar may offer a potential life longer than the period that plant protection will cover so it is important for market penetration to be at the highest level possible in the years after commercial release. In the United Kingdom and Europe, retail packs of raspberry cultivars are now labeled with the cultivar name (H.A. Daubeny, pers. comm.; H.K. Hall, pers. observ.). This may increase sales of a new cultivar and enable a quicker market penetration driven by the consumer desire for quality and the recognition of a superior product. If naming of fresh-market raspberries in the marketplace becomes widespread, marketing by speciality sales or as ‘‘club’’ cultivars might be considered. I. Propagation When planting a raspberry field, the health status of planting stock used has a tremendous effect on production and profitability in the future. Planting material should be free from pests and virus, bacterial, and fungal diseases (Jenner and Parminter 1981). As raspberry cultivars are all clonal in nature, it is of key importance to make sure that high-health stock that is true to type is used for propagation to ensure high yield and best fruit quality (Bite and Petrevica 2002). Use of fruiting fields as a source of planting stock is unwise, especially older fields that have pest or disease issues. After selections have been clonally propagated and found true to type, they may be recognized and registered as a cultivar.

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Propagation methods used for bulking raspberry clones and propagation issues include:       

Suckers, canes, and transplants Roots Root cuttings and other traditional methods Shoot cuttings In vitro High-health stock and trueness to type Genetic stability

1. Suckers, Canes, and Transplants. The simplest form of propagation of red raspberries is through the use of suckers or canes with attached roots that grow from adventitious buds on the roots of established plants. Multiplication of plants may come from the division of crowns into separate canes from a planting established specifically for propagation. The use of canes dug from the large number of suckers that develop around mother plants in a production field during the first two years of growth is the oldest traditional method of propagation for red raspberries (Crandall and Daubeny 1990; Jenner and Parminter 1981). Excess canes can be dug and transplanted to plant a new field. They are usually dug during the dormant season and either heeled-in in soil or mulch or bagged (prevented from drying out) and held in cold storage until planting. Sometimes foliated canes that have grown in the spring are used, but they require extra care in handling and must be transplanted immediately and kept watered to survive. Obtaining a good stand by using green plants is often difficult; this technique is usually used for small plantings or to fill empty spaces left in new fields (Crandall and Daubeny 1990). Another grade of plant available for sale in the United States is known as a transplant. These are produced by taking suckers, planting them back into a nursery for digging, and selling as crowns after another year’s growth. These are sold into the home garden trade; commercial growers do not find it worthwhile to pay the cost of these plants for field establishment (Funt et al. 1999). Commercial propagators of red raspberries use high-health stock to plant propagation beds. Overwintering canes are dug from the bed after one season’s growth. For the following 1 to 2 summers, cane growth is allowed to spread over the propagation, beds and a crop of high-health canes is dug or lifted during the dormant season (Crandall and Daubeny 1990; Dale 1987). This method is also used to produce long canes for planting high-density greenhouses and tunnels and plantings in warm climate locations for out-of-season production.

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Black raspberries perform differently from red raspberries in that the plants have a tightly formed crown that cannot be broken up like a red raspberry. Suckers also are almost entirely absent, and the plants do not spread from the original crown by suckering. In contrast, canes are arching and are able to tip root in autumn where they touch the ground, and a new crown is formed at that point. When red and black raspberries are intercrossed, the F1 purple raspberries are crown forming. In the F2 seedlings segregate for crown forming, suckering, and tip rooting; some segregates neither sucker nor have the ability to tip root. In backcrosses to red raspberry, the dominant crown-forming trait can be erased from the progenies by selection for suckering, loosecrowned types. 2. Roots. When raspberries are propagated in stool beds, digging of canes produces a large amount of roots that are not attached to canes or crowns. These have adventitious buds, which sucker and grow into young plants. They can be planted to establish a raspberry field or new stool beds. Bud break from roots is highly seasonal with minimal bud break from roots harvested from spring through the summer; roots dug during autumn and winter produce ample adventitious buds (Hudson 1934). With roots from stool beds grown in cool-climate conditions, sucker growth is prolific and establishment of plantings is very good. However, with roots produced in warm temperate conditions and mild winters, bud break from roots is reduced compared to those grown in cool temperate conditions. Even when those roots are planted in a coolclimate nursery, sucker and cane numbers are reduced. If raspberries are grown in subtropical conditions, plants of most cultivars show effects of lack of chill, and fewer root buds are formed. Bud break from roots diminishes rapidly after the first year, until no further growth is observed, usually after 2 to 3 years. Roots are planted as hills using 200 kg/ha (170–230 kg/ha) of roots for hills or 300 kg/ha (280–340 kg/ha) of roots for hedgerow plantings. For hills, 40 to 60 g should be used per hill. In a hedgerow, roots should be placed continuous in the row. Roots should not be allowed to dry out (this happens very quickly on a warm windy spring day), and they should be covered with 2.5 to 4 cm of soil as soon as possible after laying in position (Spooner 2005). 3. Root Cuttings and Other Traditional Methods. A specialized adaptation from the use of roots is used for raspberry propagation in the form of root cuttings (Fig. 22 a–f ). Roots harvested in winter are laid in a propagation tray on a layer of soil mix and then covered with

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Fig. 22. Propagation by root cuttings in raspberry: (A) Roots layered in a tray; (B) Root cutting ready to harvest; (C) Root cuttings after harvest; (D) Root cuttings under mist; (E) Rooted cuttings; (F) Potted cuttings. (photos by H.K. Hall).

2.5 cm of mix. Propagation trays are placed in a greenhouse and kept moist, as would be normal for growing seedlings. Root suckers soon begin to sprout. When they are 1 to 3 cm tall, they are cut using a scalpel and placed in a propagation mix under mist, with or without rooting hormone. Some cultivars benefit from the use of rooting hormones; others root effectively without the need of hormone. Key to rooting is a 2-cm section of stem on the cuttings that has been etiolated. Completely green shoots root less effectively and sometimes not at all. Root cuttings can be very effective in bulking up 1 plant to as many as 300 in a single year without the use of tissue culture. This practice is

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very good for quicker bulk-up for trials of breeding selections (Hudson 1934). For propagation of raspberries for nursery sales to home gardeners, often root cuttings, canes, or tissue-culture plants are used to produce potted plants that are grown on for nursery sales. 4. Shoot Cuttings. The use of primocane cuttings for propagation in early to midsummer is also possible, but results can be variable and often are not successful (Jenner and Parminter 1981; Howard and Tal 1985). Jenner and Parminter (1981) reported some success using a propagation tunnel and cuttings dipped into 0.1% indole butyric acid (IBA) commercially formulated as Seradix No. 1 rooting hormone. Cuttings were placed in a moist 50:50 peat-sand mixture under a plastic tunnel under semishade, sprayed with Captan, and kept enclosed for rooting to take place. Improved results were obtained by Howard and Tal (1985) using tip cuttings from new canes about 60 cm tall and lateral shoots of regrowth about 30 cm long a month later. Cuttings were dipped in 250 mg/l IBA in 50% aqueous acetone to a depth of 8 mm and placed in a 20 C bottom-heated propagation bed under a ventilated, high humidity fogging system. Heavy callus was developed after 14 days, and rooting was observed after 40 days. Pretreatment of cuttings by standing them for 24 hr in 2% sucrose solution reduced basal necrosis overall from 22% to 13% and increased the number of cuttings with large branched root systems from 24% to 55%. A high-peat compost 75:25 peat-sand mix gave higher levels of rooting than the 25:75 mixture. Foliar feed and fungicide sprays were applied twice weekly. With black and purple raspberries, propagation by the use of stem cuttings is much more successful than with red raspberries, as cuttings root quicker and do not die off nearly as much as red raspberries. Successful propagation by root cuttings is closely related to the ability of black raspberries to tip root when cane tips touch the ground and the propensity of canes to root at nodes when pinned to the ground or covered. It may be possible to introgress the dominant easy-rooting trait from black raspberries to red raspberries to reduce propagation difficulties in future. 5. In Vitro. Initial attempts with the use of tissue culture for propagation of red raspberries were only moderately successful (Anderson 1980). Anderson considered it unlikely that red raspberries would be propagated by tissue culture in preference to the use of root cuttings unless it was used to rapidly increase stocks to commercial

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quantities, to maintain germplasm, or to increase disease-free planting stocks. Propagation of blackberries in vitro is much easier and usually quicker than raspberries, but for most cultivars of raspberries tissue culture propagation is viable, and gained greater prominence in the 1980s (Donnelly and Daubeny 1986). Tissue culture propagation is now used routinely in many nurseries and breeding programs around the world. All selections in some larger programs are collected from the field and immediately placed in tissue culture. Any virus and disease infection is cleaned up, and plants can be quickly propagated for largerscale trials. Stocks of high-health material are generated to be used as nuclear stock for further propagation if required. Establishment of cultures is most successful during the springtime. The use of plant material that has been kept in a greenhouse under a fungicide spray program is very beneficial for improving success in getting good initiation and clean cultures. Initiation of cultures as early as possible in spring is very important for primocane-fruiting types so that meristems can be initiated that have not already differentiated to form flower initials. Tissue-culture media successfully used for propagation of raspberries include Linsmaier and Skoog, Murashige and Skoog (MS), Anderson’s, and Lloyd and McCown (Anderson 1980; James et al. 1980; Murashige and Skoog 1962; Pelto and Clark 2000). Tissue-culture laboratories predominantly use indole butyric acid (IBA) as the source of auxin and 6-benzyl-aminopurine (BA) as the cytokinin (Pelto and Clark 2000). Reed (1990) screened 256 accessions of Rubus germplasm for in vitro regeneration and proliferation on MS and Anderson basal salt formulations. Thirty-four percent of these, including 65% of the raspberries, were successfully cultured on Anderson basal salts. Most accessions proliferated on media containing 1 mg/L BA, 0.1 mg/L IBA and 0.1 mg/l GA3; only a few required 2 mg/L BA. Rooting was encouraged in some clones by transferring to full-strength MS medium without plant growth regulators. Ferric ethylenediaminetetraacetic acid (FeEDTA) as the source of iron for tissue culture of raspberries is satisfactory in many cases, but some laboratories find that Sequestrene 0.004% as the iron source substantially improves the growth of plants in culture (Gonzalez et al. 2000). Gonzalez et al. (2000) also removed the calcium from Anderson’s macronutrients to promote growth in the raspberry cultivar ‘Gradina’. Growth and rooting of raspberries in vitro is also promoted by adding activated carbon to the medium (Pelto and Clark 2000). With some cultivars, growth was promoted by the use of fructose instead of sucrose

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in the growing medium. Deng and Donnelly (1993) reported the use of CO2-enriched atmosphere and reduced sucrose in the medium for tissue culture of red raspberries and found that it promoted in vitro hardening of the raspberry plantlets. They suggested that CO2 enrichment could be used as an alternative to sucrose for the carbon source for tissue culture. In some laboratories, it is standard to include heat treatment to the protocol of preparing raspberry plant material for culturing. This generally promotes the growth of plants in culture (Donnelly and Daubeny 1986). Growth and multiplication rates of raspberries in culture are significantly reduced by bacterial and virus infection, even if there are no obvious symptoms to either infection (Tsao et al. 2000). In one case a bacterium was systemic in the plant in culture but after plants were ex-flasked, over half of the plants died when they were weaned off mist and hardened off (H.K. Hall, pers. observ.). 6. High-Health Stock and Trueness to Type. Growers are now encouraged to use only certified plant material to establish new plantings. This practice has significantly slowed the deterioration of planting stocks for commercial production of raspberries, as was experienced with many cultivars in the 20th century. ‘Lloyd George’ is an example of a cultivar lost to commercial production through the effects of (RBDV). In the United Kingdom, this cultivar was released in 1920 and became RBDV infected within 10 years. However, it was observed virus free in New Zealand in 1945 and sent back to the United Kingdom as foundation stock for propagation (Hudson 1947), only to be lost again within a short period. ‘Lloyd George’ had an enormous impact on the development of new floricane-fruiting cultivars of red raspberry as well as being the key founding parent for the development of the primocane-fruiting trait. ‘Meeker’, the premier cultivar of the Pacific Northwest for process production, is maintaining its place in production only through the efforts of tissue-culture laboratories and the high-health certification programs in the United States and Canada. Nevertheless, the period of production for ‘Meeker’ before the plants become RBDV infected and commercially unacceptable has dropped to as little as 5 years in some plantings (H.K. Hall, pers. observ.). In New Zealand, plants of ‘Marcy’ widely planted in former years were uniformly infected with RBDV. This infection was spread throughout the country by the practice of using production fields as the source of plants for new fields. In addition, the disease Silver leaf (Chondrostereum purpureum ¼ Stereum purpureum) was also shipped

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to other planting sites, as were crown gall and other diseases (H.K. Hall, pers. observ.). For high-health nuclear stock production and maintenance, plants are virus tested, heat treated, and cleared of virus before being multiplied by tissue culture and supplied as certified mother material for propagation. After tissue-cultured plants are grown out, they are typically increased for two generations of propagation in the field before being sold as certified plants, providing they have passed the required inspections for trueness to type and freedom from weeds and other issues in the propagation fields. A mix-up in the tissue culture laboratory or in the field is very serious for a commercial nursery, and it can cause significant problems for both the nurseryman and for the grower if it has not been recognized during the certification process. This was a significant issue in the United Kingdom when ‘Glen Shee’ and ‘Glen Ample’ were mixed up in propagation (Glens mix-up cost to raspberry 1999). In the Pacific Northwest, ‘Meeker’ was found to be contaminated in one nursery, and it required a significant effort to remove less than 1% contamination with ‘Willamette’ in the field so that the plants could be certified and sold (H.K. Hall, pers. observ.). In trial plots of another nursery in the same area, selections under trial were mislabeled and there were several mix-ups in plots of at least two successive trials. At EMR there has been an ongoing battle with the resistance-breaking strain of RBDV (RB-RBDV) in trial plots and in breeding fields. It is a testament to the efforts in high-health management for propagation that this disease has not been spread abroad from their trial fields. 7. Genetic Stability. Mutations also are an area of concern for breeders, tissue culture propagators, nurserymen and growers. Genetic instability in raspberries is relatively common, and aberrant types are found in every cultivar that has been bulked up for large-scale commercial plantings. Most of the aberrations in plant growth are inconsequential as they occur in single plants in the field; for example, single or even some multiple cane mutants with genetic chlorosis are found at a low level among plantings. Another common mutant is for yellow- or gold-fruited mutants, especially in those cultivars with the recessive gene for yellow fruit color. Six cultivars that contain the recessive yellow gene i are ‘Autumn Bliss’, ‘Cuthbert’, ‘Heritage’, ‘Indian Summer’, ‘Meeker’, and ‘Willamette’. Each of these has produced sports with yellow-golden fruit, and several of them have been released as cultivars. From ‘Autumn Bliss’ has come ‘Golden Bliss’ (‘Allgold’ in the United Kingdom); from

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Cuthbert have come ‘Golden Queen’ and ‘Perry Golden’; from ‘Heritage’ have come ‘Goldie’ and ‘Kiwigold’; from ‘Indian Summer’ has come ‘New York Times’; from ‘Meeker’ have come several golden selections, one of which have been released as the commercial cultivar ‘Lisa’ (Nikolic´ and Milivojevic´ 2008); and from ‘Willamette’ has come ‘Better Homes and Gardens’. A yellow sport of ‘Malling Delight’ also was maintained at SCRI for some time but now has been lost (D.L. Jennings, pers. comm.). Other cultivars with the recessive yellow gene include ‘Lloyd George’, ‘Sumner’, ‘Chilcotin’, ‘Lewis’, ‘Tadmor’, and ‘Fairview’. Several cultivars have also mutated to become genetically spineless, including ‘Willamette’, ‘Zefa 2’, and ‘Multiraspa’, resulting in clones that have dominant spinelessness. However, no breeding value has been found with this material. Another mutation of potential value is the mutations of ‘Malling Jewel’ and ‘Malling Promise’ to give plants with the dominant gene L1, affecting fruiting laterals and stimulating the production of very large sepals, stipules, and fruit (Jennings 1993). This gene was used in breeding in Scotland (SCRI), England (EMR), Canada (PARC-BC), the United States (WSU, ORUS), Russia, and New Zealand. The cultivar ‘Glen Garry’ was been released from SCRI containing gene L1 as well as a range of cultivars from Russia (Kichina 2005b). Use of gene L1 types for breeding has been abandoned in most locations because of genetic instability. In spite of instability, some selections with the reverted gene have been very valuable for breeding and also of commercial potential. In Russia, one gene L1 selection derived from the large-fruited types with this gene from Scotland has been released as the cultivar ‘Generalissimos’, with fruit up to 23 g in weight (Fadjukov 2003). A photograph of this cultivar (http://www. eco-rus.info/text/poselenia/posrast/posraysad1.htm) shows that the plant has some appearance of tetraploidy. It will spark considerable interest for raspberry breeders. Genetic stability in propagation is of greater importance than within commercial fields, assuming plants have been true to type when set in the field. Mutation rates in commercial fields may be as high as 0.05% to 0.1% or higher (Kichina and Ogoltzova 1973, 1975), and similar rates of genetic change may be expected in propagation fields. In propagation fields, genetic stability becomes more important when there are two or more generations of propagation before plants are fruited and checked for trueness to type (Jennings 1993). However, if plants are inspected by trained personnel, aberrant types may be rogued before plants are sold, as variation in morphology often signals changes that will affect fruit quality and production. If tissue culture is used for bulking plant material before plants are set in a field nursery, there is a significantly

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greater likelihood of undetected mutations arising in a cultivar or selection (Jennings 1993). When adventitious buds are propagated in tissue culture, rather than apical or axillary meristems, the risk is increased significantly, as there is greater genetic variation when new buds are generated within callus or around the base of a shoot. In New Zealand, this was observed when tissue culture was used to bulk up ‘Tadmor’ raspberry for commercial propagation. ‘Tadmor’ itself was slow to grow in culture and difficult to get numbers required for the order. In one subculture, multiplication increased significantly, and this eventually comprised much of the order. Differences between the somaclonal variant and ‘Tadmor’ included earliness, very spiny canes, greater cane numbers, extremely vigorous spreading growth, leafiness, soft rough fruit that were very susceptible to fruit rots, and hard to pick. (‘Tadmor’ was semispineless, had a moderate number of upright canes and open bush habit. Fruit was large, firm, well formed, had good shelf life, easy to harvest, and the harvest season was very late). When the tissue-cultured plants were placed in the field, the somaclonal variant produced many canes. These were dug for further plantings, making the new fields almost entirely the aberrant type. Particular problems have frequently occurred in propagation with plants mutating to produce crumbly fruit (Daubeny et al. 1967; Jennings 1967b, 1993; P.P. Moore and Robbins 1990). At WSU, plant material of ‘Sumner’ and ‘Centennial’ became crumbly during the propagation process, and in the United Kingdom, ‘Malling Promise’, ‘Norfolk Giant’, and ‘Malling Jewel’ showed similar effects in some propagation lines. Crumbly fruited clones were a significant problem for propagators. In propagation, it is important to devise a protocol that tracks different lines of a selection or cultivar so that the likelihood of significant commercial loss can be reduced. If a problem occurs within a propagation line, this means that only part of the multiplication will be affected rather than the whole of that clone. In tissue culture, both the time a plant is maintained in culture before reinitiation and the number of generations of subculturing should be recorded. A regular program of reinitiation should be maintained to reduce the risk of propagation problems occurring in culture and taking over the whole of the propagation of a clone. Efforts should be made to avoid using adventitious buds for tissue culture propagation in culture, and a regular program of sampling should be followed to progeny-test the propagules coming from each initiation and each propagation line. When tissue culture propagation lines are moved into a nursery, tracking of propagation lines should be continued so that a problem

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line can be removed or targeted for rouging, rather than requiring the whole propagation field or total of one selection or cultivar to be subjected to culling or rouging. J. Molecular Techniques The advent of biotechnology has resulted in a fundamental shift in detecting and monitoring genetic variation in plant breeding and genetic studies (C.A. Weber, pers. observ.). Classical breeding, which selects parents and their desirable offspring based on an observable phenotype, is being integrated with techniques that can identify and manage genetic variability at the molecular level (protein or DNA). The ability to detect genome-wide variability has led to the characterization of genetic variation within not only coding regions (i.e., genes and their morphological manifestations) but also in noncoding regions, which make up large portions of plant genomes. These developments have enabled the construction of genetic linkage maps of red raspberry containing numerous genetic markers that are phenotypically neutral, which have been used to identify genomic regions associated with phenotype. Additionally, methods to transform or genetically modify plants have the potential to provide practically unlimited variation to plant breeders. Progress in genetic modification is limited more by rates of gene discovery, intellectual property issues, and public preferences than by the techniques used to modify genomes. A variety of molecular marker techniques including isozymes, random amplified polymorphic DNA (RAPD), simple sequence repeats (SSR), amplified fragment length polymorphism (AFLP), and others, have been employed in genetic studies of raspberry. Most studies have been for (1) detecting and quantifying genetic variation at the DNA level; (2) determining taxonomic relationships; and (3) locating genetic loci controlling a trait(s) for marker-assisted selection (MAS) and/or for novel gene discovery from exotic germplasm. Techniques for genetic modification have been successfully modified from other species for use in raspberry, and there is every reason to believe future applications will be successful as well. The next section reviews the application of molecular techniques in the genetic studies of cultivated raspberry (R. idaeus, R. arcticus, and R. occidentalis) as well as other Rubus species with raspberry-type fruit (i.e., fruit separates from the receptacle at maturity). 1. Diversity and Taxonomy. Many studies have utilized molecular markers to quantify genetic diversity in wild raspberry populations as

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well as among breeding programs and cultivars. Further use has been made in classifying that diversity and elucidating the relationships among the many hundreds of Rubus species. Early work with starch gel electrophoresis and isozyme staining demonstrated their utility in detecting variation in Rubus species. Naruhashi and Masuda (1986) showed that peroxidase staining patterns varied among many Rubus species including several raspberry types, as well as among tissues of different ages within each species. They also noted patterns corresponded broadly to cane and leaf patterns hinting at the possibility of genetic mapping using isozymes. Patamsyte˙ et al. (2004) analyzed the correlation between soil acidity and the isozyme pattern of superoxide dismutase (SOD) among 20 wild R. idaeus genotypes but found no relationship. DNA fingerprinting techniques have also been utilized to investigate diversity and population dynamics in raspberry. Nybom and Schaal (1990) developed fingerprints with a radioactive minisatellite probe in black raspberry. Tandem repeats of a core sequence were highly variable within a black raspberry population, identifying 15 genotypes in a sample of 20 individuals. P.P. Moore (1993a) probed restricted DNA from 22 red and purple raspberry genotypes with sequences from a chloroplast library to investigate maternal ancestry. Maternal ancestry from R. occidentalis, R. parvifolius, and R. strigosus could be differentiated from R. idaeus vulgatus Arrhen., from which arose all of the commercial red raspberry cultivars in the study. Random amplified polymorphic markers have been used widely in raspberry for taxonomic studies (Graham and McNicol 1995; Pamfil et al. 1997, 2000; Trople and P.P. Moore 1999) and germplasm diversity assessments (Badjakov et al. 2006; Graham et al. 1994, 1997, 2003; Patamsyte˙ et al. 2004; Weber 2003). Graham et al. (1994) used the distribution of markers from nine RAPD primers to produce a similarity index and a hierarchical tree for 10 red raspberry cultivars. Graham and McNicol (1995) used RAPDs to elucidate relationships among 13 Rubus species including seven raspberry types. A principle coordinate analysis and similarity index showed divergence in the presumed taxonomic relationships among these species. Trople and P.P. Moore (1999) calculated genetic similarities among 43 Rubus species, including multiple raspberry types, based on marker profiles from six RAPD primers. The similarity indices were relatively low between various species (0.15 to 0.52) with much higher indices within species with multiple accessions (0.62 to 0.82). Pamfil et al. (2000) analyzed 40 species of Rubus, including many raspberry types, in relation to success of interspecific hybridization. Classification of the species

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using RAPD markers agreed with the traditional classification of Rubus in most cases, except for three species in the subgenus Malachobatus that clustered with the raspberry types in subgenus Idaeobatus and the reverse of this relationship for one species. However, RAPD-based taxonomy could not explain the success of interspecific hybridization within each subgenus. In other work, Graham et al. (1997) used RAPD markers to examine relationships and spatial diversity in wild populations of R. idaeus in Scotland. Wild accessions from four sites were compared to each other and the commercial cultivar ‘Glen Clova’ using six RAPD primers. Most of the variability in markers was observed between the collection sites. Within sites, increasing diversity coincided with greater spatial separation. None of the wild populations was closely related to the commercial cultivar. Later, Graham et al. (2003) assayed a wider range of wild R. idaeus from 12 sites across a greater area of the United Kingdom and compared the accessions to the cultivar ‘Glen Moy’. Again, greater genetic similarity was found within each population collected, which indicates limited of gene movement across geographic locations. Additionally, little gene flow was observed between wild populations and commercial cultivars. Gene flow within and between these wild populations was subsequently studied using SSR markers, which confirmed limited gene flow (J. Graham, pers. comm.). Patamsyte˙ et al. (2004) analyzed 20 wild R. idaeus accessions from a Lithuanian germplasm collection for genetic diversity using 285 RAPD loci produced from 36 primers. Genetic distances among the genotypes did not correlate to geographic distances between collection sites. When ecological conditions were analyzed in comparison to the RAPD marker, soil acidity was significantly correlated to observed polymorphisms, indicating an environmental effect on diversity within populations. Badjakov et al. (2006) analyzed 28 raspberry genotypes from the Bulgarian germplasm collection including 18 Bulgarian cultivars and breeding lines, 8 accessions from outside Bulgaria and two wild species accessions, R. occidentalis and R. adiene. A set of four RAPD primers generated markers used to create a genetic similarity tree. Two clusters were clearly visible among the Bulgarian genotypes, which corresponded to two pedigree groups. Weber (2003) analyzed the genetic relationship among and between black raspberry (R. occidentalis), red raspberry, and a blackberry hybrid genotype using RAPD markers. Black raspberry genotypes showed an 81% genetic similarity with the 11 least variable black raspberry genotypes being 92% similar. This compared to 70% similarity measured among red raspberry cultivars (Graham et al. 1994). Five

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genotypes accounted for 58% of the observed variability in black raspberry. Of the 16 genotypes investigated, none was more than two generations from at least one wild ancestor, further indicating a lack of genetic variability in black raspberry cultivars. The development of molecular markers has been driven by the need for saturated maps for breeding and gene function studies. Amplified fragment length polymorphisms combine the hypervariability of restriction site polymorphisms seen in restriction fragment length polymorphisms (RFLP) with the ease of PCR-based reactions. This marker type has been used to investigate diversity and population dynamics in multiple Rubus species. Amsellem et al. (2000) investigated the diversity of the weedy raspberry species R. alceifolius Poir. in its native range and in areas where it has invaded as a noxious weed. Considerably more genetic diversity was detected in its native range, with diversity in nonnative ranges dependent on distance from the origin. Multiple introduction sites could be identified in some cases based on marker profiles from different populations. Amsellem et al. (2001c) also used AFLP to show that reproduction in the native range of R. alceifolius is through sexual means and through apomixis in introduced locations. Lindqvist-Kreuze et al. (2003) also used AFLP markers to characterize diversity in 6 populations of wild Arctic raspberry (R. arcticus L.) and 10 cultivars in Finland. AFLPs produced a multitude of markers able to distinguish 78 genotypes from 122 samples. Genetic variation was high within populations, indicating a high degree of sexual reproduction, but interpopulation gene flow was low as measured by overall diversity among locations. Diversity within the cultivars was also high to the point of being able to differentiate subspecies. Simple sequence repeat (SSR) or microsatellite markers have also been developed for Rubus to catalog the hypervariable microsatellite regions of the genome. Amsellem et al. (2001b) demonstrated their utility in the weedy species R. alceifolius for looking at diversity over native and invasive ranges as well as for tracking interspecific hybridization among overlapping Rubus species. Amsellem et al. (2001a) also used SSR markers to show that reproduction within its native range was sexual while apomixis was common in nonnative locations. Polymorphic microsatellite loci have been used as a tool to investigate gene flow between cultivated and wild raspberry (2002). Badjakov et al. (2006) also used SSR markers to assess the genetic diversity in Bulgarian germplasm accessions. Twenty-eight accessions were screened at four SSR loci, demonstrating high levels of diversity within the collection.

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Various other molecular marker systems have been used to quantify diversity in raspberry species including variable number tandem repeats (VNTR) and internal transcribed spacer region (ITSR) polymorphisms. Busemeyer et al. (1997) utilized DNA probes from two repeated core sequences to examine diversity at VNTR loci in the wild populations of R. moluccanus L. in the Philippines. The results were similar to that of Graham et al. (1997, 2003) with more similarity found within populations at each location than that found between location. Additionally, apomictic reproduction was ruled out in these populations because no identical VNTR patterns were identified. Alice and Campbell (1999) produced a Rubus phylogeny of 57 species including multiple raspberry species based on variability in the ITSR sequences. ITSR sequences were found to be generally consistent with biogeography and ploidy levels but less so with morphological traits. 2. Cultivar Identification. Multiple marker systems have been used for cultivar and breeding selection identification. Cousineau and Donnelly (1989a,b, 1992b) analyzed six isozymes to characterize 79 red, black, and purple (R: idaeus  R: occidentalis) raspberry cultivars and breeding selections and were able to detect mislabeling among plant sources. However, 24 of these genotypes could not be uniquely characterized using these isozymes. RAPDs have also been utilized in many Rubus species for cultivar identification (Graham et al. 1994; P.P. Moore 1995; Parent et al. 1993; Weber 2003). Parent et al. (1993) tested 19 primers on 15 red and purple raspberry cultivars and found a combination of 3 primers produced markers that could differentiate all of the cultivars in the study. In a similar study, Graham et al. (1994) produced specific RAPD fingerprints for 10 red raspberry cultivars using 9 random primers. In black raspberry, Weber (2003) found that the marker profile from 6 RAPD primers could be used to differentiate 16 cultivars and selections. RAPD marker-derived sequence characterized amplified region (SCAR) markers were also develop for cultivar identification by Parent and Page (1998). Five RAPD markers were cloned and sequenced for development of SCAR markers with 4 producing polymorphisms useful for identifying 15 purple and red raspberry cultivars. Other marker systems have also been used in cultivar identification, including variation in intersimple sequence repeat (ISSR) sequences and minisatellite DNA fingerprints. Sobolev et al. (2006) used ISSR markers that can identify variation in the DNA between SSR areas of the genome to identify Russian raspberry cultivars. Nybom et al. (1989) probed restricted DNA from 10 raspberry cultivars for minisatellite

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sequence variation to produce cultivar-specific DNA fragment profiles that could identify each cultivar. Similarly, Nybom et al. (1989) and Nybom and Hall (1991) probed 6 black and red raspberry genotypes and other Rubus samples to produce cultivar-specific DNA fragment profiles. Estimates of similarity based on fragment profiles coincided strongly with genetic relatedness based on pedigree analysis. Parent and Page (1992) utilized nonradioactive minisatellite probes to produce DNA fingerprints, producing unique fingerprints for 15 purple and red raspberry cultivars. Castillo et al. (2007) examined genetic stability of cultivars after in vitro culture and cryopreservation using SSR and AFLP markers. Bassil is documenting SSR fingerprints of standard cultivars with DNA extracted from young leaves. In addition, her laboratory has been successful at extracting DNA and analyzing SSR cultivar identity from Rubus receptacles and fruit (N. Bassil, pers. comm.). 3. Inheritance and Genetic Mapping. Prior to the advent of molecular markers, inheritance and genetic mapping studies were limited to simple morphological traits (Jennings 1988; Ourecky 1975a). The development of various marker systems has made whole genome mapping possible and aided in the study of inheritance of more complex or quantitative traits. Cousineau and Donnelly (1992a) studied the inheritance of five isozymes in 15 red and purple raspberry F1 progenies. Deviations from Mendelian inheritance were observed in three of four populations for the isocitrate dehydrogenase (Ihd-1) locus and higher than expected aberrant segregation ratios for four other isozymes. Analysis of jointly segregating loci revealed a possible linkage group consisting of the malate dehydrogenase (Mdh-1), triose phosphate isomerase (Tpi-2), and phosphoglucomutase (Pmg-1) loci. SSR markers have also proven to be useful in genetic mapping of Rubus. Stafne et al. (2005) tested 142 SSR markers developed from Rubus and Fragaria L. (strawberry) on raspberry and blackberry parental genotypes to assess their utility in genetic mapping. In raspberry, 60 SSR primer pairs were found to have potential for mapping. Lewers et al. (2005) developed SSR markers from GenBank sequences from related species in the Rosaceae and from a genomic strawberry library. Development of SSR makers was not efficient outside the closely related genera in the Rosoidae subfamily and only moderately useful within the sub-amily with poor transference among species. The first genetic map of raspberry was developed by Graham et al. (2004) utilizing SSR and AFLP markers for a population of ‘Glen Moy’ 

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‘Latham’. SSR markers were developed from both genomic and cDNA libraries from the cultivar ‘Glen Moy’, and AFLP markers further saturated the map for quantitative trait loci (QTL) analysis for complex morphological traits. A genetic linkage map was produced consisting of nine linkage groups with 273 markers covering 789 cM of map distance. QTL analysis for variability in spine density identified two associated regions on linkage group 2. Analysis of the production and spread of root suckers identified two regions on linkage group 8 associated with the spread of root suckers from the mother plant and one similar region associated with sucker production. Graham et al. (2006) later added 20 SSR markers to the ‘Glen Moy’  ‘Latham’ map along with analyzing data on the H gene for cane hairiness and resistance to multiple fungal pathogens. The H gene was mapped to linkage group 2 and associated closely with resistance to cane Botrytis and spur blight. Resistance to cane spot was mapped to a different region of linkage group 2 and linkage group 4, and yellow rust resistance was mapped to linkage group 5. Root rot resistance has also been mapped in this ‘Latham’  ‘Glen Moy’ cross, with QTL on two linkage groups (J. Graham, pers. comm.). Pattison et al. (2007) combined generational means analysis with molecular markers and QTL analysis to map resistance to Phytophthora root rot in a BC1 population of NY00-34 (‘Titan’  ‘Latham’)  ‘Titan’. Separate genetic linkage maps of NY00-34 and ‘Titan’ were developed using RAPD, AFLP, and resistance gene analog polymorphisms (RGAP) and analyzed for QTL associated with various parameters of root rot resistance assayed in a hydroponic system (Pattison et al. 2004). Regions on linkage groups 1, 5 and 7 were associated in multiple parameters of the resistance response. Bulked segregant analysis (BSA) corroborated this conclusion by identifying markers from these regions associated with bulked samples of resistant and susceptible genotypes. Generational means analysis suggests two major genes controlling resistance, possibly corresponding to the two regions on each parental linkage map associated with resistance. Attempts to develop markers for other viral resistance genes have been carried out for raspberry leaf spot and raspberry vein chlorosis utilizing the ‘Glen Moy’  ‘Latham’ cross of Graham et al. (2004). Field screening was carried out to measure symptom production of leaf spot and vein chlorosis in two different environments. These traits were analyzed for significant linkages to mapped markers and resistance loci were found on linkage groups 2 and 8 (Rusu et al. 2006). Markers associated with Bu loci for resistance to RBDV are also under development in germplasm derived from the resistant cultivar ‘Newburgh’ (C. Weber, pers. comm.)

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Recently, Sargent et al. (2007) mapped the A1 locus conferring aphid resistance and the dw locus conferring dwarfing habit in a population of ‘Malling Jewel’  ‘Malling Orion’ with AFLP and SSR markers. A map of 505 cM with seven linkage groups was produced with A1 and dw mapping to linkage groups 3 and 6, respectively. Genetic linkage maps have the potential for use in marker-assisted selection (MAS) to increase the efficiency of breeding new cultivars and for integrating new traits from related species. Work toward the genetic mapping of health-related compounds has also been initiated in Rubus (Stewart et al. 2007). The construction of the first publicly available red raspberry BAC library from the European red raspberry, cultivar ‘Glen Moy’, has been carried out. Currently, the library comprises over 15,000 clones with an average insert size of approximately 130 kb (six to seven genome equivalents). Hybridization screening of the BAC library with chloroplast (rbcL) and mitochondrial (nad1) coded genes revealed that contamination of the genomic library with chloroplast and mitochondrial clones was very low (< 1%) (Hein et al. 2004, 2005). Initial screening of the BAC library employed probes to chalcone synthase, phenylalanine ammonia lyase, and a MADS-box gene involved in bud dormancy (I. Hein, pers. comm.; B. Williamson, pers. comm.). More recently, the library has been probed with genes involved in epidermal cell fate (J. Graham, pers. comm.; B. Williamson, pers. comm.; C.E. Woodhead, pers. comm.) and a peach ever-growing gene (A. Abbott, pers. comm.). 4. Genetic Transformation. Genetic transformation techniques in raspberry have largely followed the progress in other fruit crops. Graham et al. (1990) reported the first successful transformation of red raspberry utilizing the binary vector system of Agrobacterium tumefaciens. Transformed plants were produced from leaf discs and internodal segments of one raspberry genotype and two raspberry  blackberry genotypes that carried the b-glucuronidase (GUS) marker gene. It was found that the nptII gene, which provides resistance to the antibiotic kanamycin, was a poor selectable marker gene because kanamycin inhibited organogenesis at the level needed for selection. Mathews et al. (1994; 1995) later transformed the cultivars ‘Meeker’, ‘Chilliwack’, and ‘Canby’ with a gene encoding S-adenosylmethionine hydrolase (SAMase) using the binary vector A. tumefaciens system using petiole, node, and leaf explants. The use of the selection marker gene for hygromycin phosphotransferase (hpt), which provides resistance to the antibiotic hygromycin, was more effective than the

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nptII gene with rates of transformation as high as 49.6% in ‘Meeker’. SAMase lowers the production of ethylene in the plant and could in theory inhibit softening in fruit, thus increasing shelf life. Mezzetti et al. (2002) reported transforming the cultivar ‘Ruby’ also using the A. tumefaciens system. The defH9-iaaM auxin-synthesizing or parthenocarpic gene with the nptII gene as a selectable marker was inserted with the goal of improving the productivity of raspberry. Greenhouse trials showed a significant increase in fruit size and yield over two harvest seasons. Subsequent field testing under standard cultivation practices showed a significant increase in flowers per inflorescence and plant (Mezzetti et al. 2004). This translated into an increase in fruit number that were larger in size and a 100% increase in yield. Martin and Mathews (2001) reported the transformation of the ‘Meeker’ cultivar with the A. tumefaciens system with six constructs based on the coat protein and movement protein genes of RBDV, which causes crumbly fruit in raspberry. Grafting tests with infected material to test for resistance resulted in 53 of 141 transgenic lines remaining virus free for two rounds of grafting. Subsequent lines were developed with these genes as well as nontranslatable RNA of RBDV (Martin et al. 2004) with 5 of 197 lines remaining RBDV free for 5 years in field testing with heavy disease pressure. Partial resistance was also observed in additional lines. Fruit quality comparisons were similar to control plants. Kokko and Ka¨renlampi (1998) successfully transformed the Arctic raspberry, R. arcticus, also using binary vector A. tumefaciens system utilizing the cauliflower mosaic 35 S promoter (CaMV 35 S) to drive the expression of the gus-int gene and the nptII gene as a selectable marker gene. Stable expression was maintained over 3 years in in vitro cultures. Friedrich and Va´chova´ (1999) utilized an alternative method of transformation in callus cultures of the cultivar ‘Stolicznaya’ (‘Stolicnaya’). A donor plasmid was directly introduced into cells of a callus cell suspension with a 20% glycerol concentration. The plasmid in this case carried the isopentenyltransferase gene, which increases cytokinin production, with kanamycin and tetracyclin resistance as selectable markers. Subsequent growth of callus cells on selectable media lacking cytokinins indicated transgenic lines. No plants were developed from the lines for further testing. There is clear potential for improving raspberry cultivars using genetic modification techniques. Disease resistance and yield improvements have been shown in limited trials with no apparent fruit quality consequences. However, public sentiment and uncertain environmental consequences has kept this technology in the test phase in raspberry for the time being.

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IV. BREEDING SYSTEMS A. Genetic Structure The chromosome morphology of Rubus species and secondary pairing at meiosis indicate that the chromosome complements are made up of 7 basic chromosomes (x ¼ 7) (Ourecky 1975a). The naturally occurring range of chromosome numbers in Rubus is from 2n ¼ 2x ¼ 14, the diploid state, to possibly 2n ¼ 18x ¼ 126, including odd-ploids and aneuploids (Bolkhovakikh et al. 1969; Britton and Hull 1957; Darlington and Wylie 1955; Einset 1947; Heslop-Harrison 1953; Jinno 1958; Komorov and Juzepezuk 1939; Komorov et al. 1941; Meng and Finn 1999; J.N. Moore 1984; Naruhashi et al. 2002; Thompson 1995a,b, 1997). Chromosomes are small (1–3 mm in length), and nuclear DNA content ranges from 0.56 to 0.59 pg in diploid species (Lim et al. 1998; Meng and Finn 2002). Two satellite chromosomes have been observed in diploid R. idaeus and R. ulmifolius (Heslop-Harrison 1953). The 7 chromosomes of red raspberry have been identified and compared with those of R. coreanus Mig. (Daubeny 1996). They differed in several ways, including the number with satellites (Pool et al. 1981). Chromosome pairing in diploid hybrids between R. idaeus and R. parviflorus showed that differences in morphology between the two species and also between the two subgenera, Idaeobatus and Anoplobatus, were not associated with structural differences between their chromosomes (Daubeny 1996; Jennings and Ingram 1983). However, differences between the two species resulted in low fertility in the F1 hybrids (Jennings and Ingram 1983). Low fertility in the F1 generation of crosses between modern red raspberry selections and cultivars and other species among the Idaeobatus is common, but full fertility may be restored in an open-pollinated F2 or in backcross generations BC1, BC2, or BC3. Fertility levels of crosses between non–R. idaeus/R. strigosus members of the Idaeobatus are often lower than crosses between Idaeobatus species and R. idaeus/R. strigosus. This has been explained by the hypothesis that R. idaeus/R. strigosus clones are intermediate between other species (Ourecky 1975a). However, it could also be explained by the assumption that there are more genes promoting cross-fertility in R. idaeus/R. strigosus clones than in other less domesticated species. Raspberry species do not contain much of the variation in ploidy level of the genus Rubus as a whole. The normal chromosome count of raspberry (Idaeobatus) species is diploid, 2x ¼ 2n ¼ 14 (Finn et al. 2002; Iwatsubo and Naruhashi 1991; Naruhashi and Peng 2002; Naruhashi et al. 2002; Thompson 1995b, 1997). A few species, such

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as R. sachalinensis Lev. and R. probus L.H. Bailey (R. mullerii F.M. Bailey), are natural tetraploids. Tetraploid clones of other species such as R. lasiostylus, R. occidentalis, R. odoratus, R. parvifolius, and R. sumatranus have been discovered, but they are not widely distributed in the wild (Finn et al. 2002; Rozonova 1939b; Thompson 1995b, 1997). Three old cultivars of raspberry have been shown to be tetraploid, ‘Colossus’, ‘Hailshamberry’, and ‘La France’ (Thompson 1997). Tetraploid sports of cultivated red raspberry clones have often been discovered in cultivation and have been developed or discovered in breeding programs. Tetraploid sports of both R. idaeus and R. strigosus have been discovered in the wild (Daubeny 1996; Jennings 1988; Thompson 1995a, 1997). Diploid raspberry cultivars also have produced tetraploid sports relatively frequently when intensively multiplied by root cuttings (D.L. Jennings, pers. comm.), and diploid raspberry crosses produced tetraploid progeny when germinating seed were treated with colchicine (Jamieson and Mclean 2008). The triploid raspberries ‘November Abundance’, ‘Belle de Fontenay’, and ‘All Summer’ also have been discovered (Darrow 1937; Thompson 1997). Other triploid selections have been produced through breeding, but they have had variable fertility. Tetraploidy in red raspberries does not give any significant adaptive value, as fruit are large and irregular, drupelets and seeds are very large, and percentage set is reduced, presumably due to irregularities occurring during meiosis that cause abortion of drupelets (Jennings 1988). In contrast, Jennings and McNicol (1989) recommended production of tetraploid red-black (purple) raspberry hybrids due to the outstanding size, set, and production of hybrids produced in the SCRI program. F1 hybrids produced from a cross between distantly related diploids results in low fertility due to poor pairing of chromosomes from the two parental genomes. In contrast, the same inability to form normal bivalents at meiosis in a diploid reduces the likelihood of formation of trivalents and quadrivalents in a tetraploid derivative from the same parental background, and the likelihood of fruitfulness in the mature plant is good (Jennings 1988). Jamieson and Mclean (2008) produced tetraploid raspberries as bridge parents for use in crosses with tetraploid blackberries. Most Idaeobatus species have some degree of compatibility with R. idaeus, the cultivated raspberry, although fruit set from crosses between wild raspberry species and R. idaeus can vary considerably, from 100% set to little or none at all (Finn et al. 2002). North American breeders reported noticeable differences in the behavior of different accessions from the same species. Fruit set from crossing and fertility of their progenies varied significantly, and the different

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clones were of varying potential value for use in breeding (Finn et al. 2002). Nevertheless, almost all raspberry breeding has focused on developing new diploid cultivars of red raspberry, utilizing variability from R. idaeus and R. strigosus. Further variation has also been incorporated by using several of the wild species from the Rubus subsection Idaeobatus. R. cockburnianus Hemsl. has been used very effectively at EMR to introgress high fruit numbers into red raspberry, resulting in ‘Malling Augusta’, a selection from the fourth backcross to red raspberry (Keep and Knight 1986). The range of germplasm from other species has made considerable penetration into new cultivar development, especially in the program at EMR. For example, seven species were involved in the development of ‘Autumn Byrd’ (Keep and Knight 2002). At the present time, all breeding programs are using R. occidentalis derivatives and many derivatives of other Rubus species in order to introduce a range of traits that will result in quality improvements, increase in yield, variation in harvest season, adaptation to new environments, and increased returns to growers, marketers, and retailers. B. Breeding Strategy Strategy for the breeding of raspberries is similar to that used for other out-breeding, clonally reproduced crops and can be affected significantly from inbreeding depression. A review of breeding strategy by Bringhurst (1983), described steps utilized by raspberry breeders along with some pitfalls that have occurred in fruit breeding programs. The strategy for beginning the domestication of a fruit crop employed four steps: 1. Identify of superior phenotypes in natural populations of chance seedlings. 2. Propagate the best selections in an agricultural setting. 3. Develop cultural practices that enhance the performance of the selected cultivars. 4. Hybridize the best selections, then select superior offspring for use as cultivars and as parents of the next generation, then repeat the process indefinitely. This defines the breeding method known as recurrent mass selection, which is based on the exploitation of relatively high additive variance conditioning the inheritance of most traits. In devising a strategy for continuing an existing breeding program or for building a new program for raspberries, the steps are slightly different but the principles remain the same:

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1. Identify superior phenotypes among available germplasm, including those that address the pertinent issues holding back production in the area where the plants will be grown. 2. Assess the best selections in an agricultural setting and identify the constraints on production for this region. 3. Develop cultural practices that enhance production of the selected cultivars and deliver optimum quality of the fruit for the intended market. 4. Hybridize among the selections chosen for commercial production and between them and germplasm chosen to introduce variability and address problems with production, quality, adaptation, pests and disease. 5. Select superior offspring for use as cultivars and as parents of the next generation, then repeat the process indefinitely. 6. Establish a deliberate protocol for evaluation and trialing of elite phenotypes so that the best selections can be chosen for commercialization within the shortest possible period. 7. Utilize up-to-date protocols for assessment and maintenance of high-health nuclear stock for mother plants and propagation methods that will result in planting stock being available to trials at the earliest opportunity. 8. Use labeling and trialing protocols and maintain control on evaluation data so that it will be possible to protect new cultivars with plant patents, plant variety rights, or plant breeders’ rights in an environment where plant protection is essential for the commercial viability of breeding programs, nurseries, producers, marketers, and retail fruit sales. Besides this overview of the strategies involved in developing and running a modern-day raspberry breeding program, it is helpful also to look in detail at strategic decisions and management employed in running the program. Overall success and profitability of a breeding program depends on achieving the desired results within the shortest possible time and delivering a product that will fit current production protocols without requiring too much change on the parts of growers, managers, shippers, marketers, retailers, and consumers. Many traditions have evolved among growers and through the marketing chain that often cannot be changed easily. Breeding progress is affected dramatically by the length of the generation time. Over the lifetime of the breeding program, profitability will be impacted by using these six strategies, which make the optimum use of available time and resources:

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1. Reduce time from the identification of superior genotypes to using them for producing an improved new diversity in the next generation of breeding. This can be achieved in floricane selections by making crosses in the year of selection using primocane flowers if they occur and in primocane types by using flowers on the remaining floricanes the spring after selection. 2. Use a coolstore to apply winter chill and hold crossing parents until brought out for crossing and a greenhouse for production of seed outside of the field fruiting season to reduce time taken to produce seed. Often this can be a valuable means of transferring inputs to a part of the year when time is available for crossing without impeding observations and data collection from the field. 3. Carry out seed treatment immediately after harvest and sow seeds without chilling for a quick production of seedlings ready to be planted the following spring or screened for pest or disease resistance. 4. Key aspects for good establishment and growth of seedlings in the field include deep well-drained soil, free of perennial weeds, that has been well cultivated; immediate watering after planting; and an ongoing management program that controls weed emergence and growth. Shelter is very important in windy situations, as is steady air movement when there is risk of frost in the springtime. In all but the coldest environments and shortest growing seasons, growth should be sufficient after the first growing season to allow an indicative crop in the following year. When breeding is for primocane-fruiting types, the first season’s growth should produce a primocane crop, although planting time needs to be as early as possible to ensure a representative harvest. 5. Selection focused on fruit quality can be accomplished in the first year of production, although fruit size/weight may not be typical of when the plant bears a full crop. Fruit are often larger when production is low in the young plants. Primocane fruit size/weight also may not be indicative of the floricane crop and vice versa. Determination of the levels of health attributes, such as anthocyanin levels, phenolics, ellagic acid, or antibacterial content, also may not be indicative from first-year fruit, although relative levels of these compounds compared to other selections appears to be consistent from year to year. 6. If outstanding selections are fast-tracked directly from the seedling field to grower trials, it may be possible to obtain a shortcut to commercial release if a selection chosen for advanced trial evaluation proves suitable for grower requirements. For success in

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this area, considerable breeder skill is required to reduce the risk of introducing an unsuccessful cultivar. A successful breeder needs to acquire intimate knowledge of the costs, management, environment, production, and quality issues faced during growing, harvesting, packing, transporting, storing, displaying, and consuming the crop. Commercial success and the value of the crop can be significantly impacted by obstacles at any step of the production and marketing chain, and breeding can address many of these issues. Four keys to breeding success include (Clark 2002): 1. The breeder’s ability to take knowledge of industry and customer needs and apply it by identifying parents that have traits (genetic variation) for improvement to meet these needs 2. The breeder’s familiarity with germplasm and detailed knowledge of trait inheritance, resulting in choice of good parental combinations and accurate identification of selections for preliminary and advanced trials in the environmental conditions required 3. The ability to grow large populations of progeny where required to attain segregants for selection 4. Adequate support in facilities and personnel to carry out all program activities for an extended period of time, including a breeding program commercialization capability for dissemination of new cultivars into the marketplace and the ability to protect new cultivars using plant patents, plant variety rights, or plant breeders’ rights A key factor in breeding raspberries is an understanding of trait inheritance. For example, at least three major genes control inheritance of spinelessness. A recessive gene, gene s, from the old R. idaeus cultivar ‘Burnetholm’ is the most used and best understood. This gene confers spinelessness in the homozygous condition ss and has a pleiotropic association with eglandular cotyledons, giving spineless plants in the F2 generation. Some spines may be on the ribs on the top edge of juvenile lead petioles, but they are completely absent from the rest of the plant. Another type of spinelessness is inherited, likely in a dominant manner, from ‘Creston’ raspberry and its derivatives ‘Haida’ and ‘Skeena’, where canes are spiny at the base but they are spineless farther from the ground and on fruiting laterals. This trait has been inherited by ‘Chilliwack’ and ‘Comox’ and a wide range of other cultivars from the PARC-BC raspberry breeding program. No inheritance studies on this gene have been published. A third and dominant spineless gene was discovered in the spineless ‘Willamette’ clone selected in Australia. This gene was not stable, and inheritance of this trait varied when the plant was used as a female or male parent (Jennings and Brydon 1990). Another spineless

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raspberry ‘Framita’, has been discovered, also found as a mutant of an existing cultivar, ‘Zefa 2’, but this has not been investigated for use as a source of spinelessness for breeding (Daubeny 1997a). A wide range of other traits have been investigated, their inheritance evaluated, and their use in breeding assessed (Anthony et al. 1986; Crane and Lawrence 1931; Daubeny 1966, 1987b; Daubeny and Pepin 1975a; Daubeny and Stary 1982; Daubeny et al. 1968; Keep 1968b,c, 1972, 1976, 1984a,c; Keep et al. 1977a,b; Jennings 1964; Jennings and Jones 1989; Ourecky 1975b). Quantitative traits are also very important in raspberry breeding, controlling resistance to some pests and diseases, growth, yield, adaptation, and many other economically important traits (Daubeny 1987b; Fejer 1977; Jennings 1983a; Misˇic´ 1970; Vrain et al. 1994). Discussions on trait objectives are found elsewhere in this review. Major improvements of quantitative traits in raspberries including fruit size, yield, and enhanced expression of some yield components have been achieved by hybridizations with species with enhanced expression of these traits and backcrossing with cultivated types or by intercrossing parents with good expression of the trait in question and recovering transgressive segregants exceeding parental performance. Inbreeding is of particular concern in raspberry breeding, except when used after wide outcrossing between cultivated raspberries and donor species for a particular trait. When this is done, selfed seedlings can often have fertility restored to the levels of the cultivated raspberry. Selfing can also be used to expose traits that have disappeared in the F1 hybrid. Selfing may also be useful in gaining access to hard-to-obtain germplasm and for genetic and inheritance studies. Nevertheless, selfing does result in weak progenies through inbreeding depression. From some sources of germplasm, it exposes genes for self-sterility and incompatibility, as well as resulting in enhanced infertility in seedling populations. Species vary in response to inbreeding, from substantial depression in red raspberry to little in black raspberry (Ourecky 1975a). Full- and half-sib crosses are often more successful with red raspberry and are used, particularly when alleles for a desired trait are present only in closely related genotypes. Backcrossing is also used widely to introgress specific characteristics from a source parent into a desired genotype. Different backcross parents are often used in each generation to avoid inbreeding depression. Eight further keys to breeding success include (Bringhurst 1983): 1. Focused strategy, directing the breeding toward commercially important criteria for each breeding generation, according to the industry that the program is supporting. The resources of time,

142

2.

3.

4.

5.

6.

7.

HARVEY K. HALL, ET AL.

land for growing seedlings, and labor each need to be used with the vision of the desired outcome in mind. Directing emphasis toward the key economic indicators for breeding success to introgress the added traits or modified characters that will make the most difference for the growers relying on the program. Inheritance of a trait should be investigated carefully to identify linkages with deleterious growth or fruiting characters before routine screening is practiced among young seedlings. Seedling numbers must be sufficient to allow expression of desirable fruiting and agronomic traits after culling of undesirable segregates. Examples of traits screened prior to field planting include spinelessness and resistance to aphids, bud moth, and root rot. Making the effort to measure important traits properly from the breeding populations. In many cases, scoring of traits is not sufficiently accurate to give detailed insight into inheritance or correctly identify the desired elite plants. Use of sampling techniques can assist this process when populations exceed the resources available to collect data. Starting at the most advanced level possible. Many programs fail to make advances as quickly as desired because they do not use the most advanced material for fruit and agronomic traits that contains the desirable trait needed. A clear example of this is the ongoing use of ‘Latham’, produced in a 1908 cross and released commercially in 1920 (Brooks and Olmo 1949), as a source of root rot resistance when resistant derivatives of ‘Latham’ with superior fruit quality, yield, and ease of harvest could be used instead. Deciding to move through the generations. The outstanding success of the SCRI and the Sweetbriar/DSA breeding programs has resulted through the use of elite selections for breeding as soon as possible after selection, in the same year or the following summer. This practice has also been used in the HRNZ, WSU, and Cornell breeding programs. Using the best selections as the parents for the next generation. Unless a selection or cultivar has a particularly desirable trait, then the decision to use only the most advanced material as parents for the next generation will pay dividends. A program also will benefit from discarding relegated material sooner rather than later so that resources can be devoted to the best prospects for growers, marketers, and consumers. Evaluating multiple generations is essential to maximize advancement and genetic gain. Programs that carry out crosses and grow

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the seedlings through to selection before doing the next series of crosses will languish compared to active breeding efforts that generate new crosses, seedlings, field populations, and trials each year. 8. Evaluating new advanced selections needs to be accompanied by agronomic trials to enable them to achieve their full potential. A management protocol can accompany a new cultivar release to assist growers in getting the best results commercially. Systematic agronomic trials of raspberry cultivars over a range of environments and with a range of management protocols was used in the Pacific Northwest. This research produced considerable innovation that has helped the introduction of new cultivars and also reduced management inputs and increased yields on existing cultivars. C. Response to Selection Under recurrent mass selection, the process of cultivar improvement depends on generation after generation improvement of breeding stocks, giving a continuous increase in alleles that have favorable effects on traits of horticultural importance. This is accomplished by selecting and mating, each generation, only those individuals that show promise of producing superior progenies (Hansche 1983). Amount, rate, and cost of selection play crucial roles in decisions that affect cultivar improvement programs, and it is important to be able to maximize the amount and rate of response while keeping the costs to a minimum. In most raspberry breeding programs, parental selection has been purely based on performance—that is, on the basis of their phenotypic response to the environment under which selection will take place. Random matings among the selected parents typical of true recurrent mass selection theory are rarely used; rather pairwise combinations are often chosen on the basis of combining desirable traits or correcting undesirable traits among the chosen parents. Many of the world’s raspberry breeding programs do not use statistically designed crossing plans or plot layouts for planting seedlings, nor in most programs is sufficient information collected to be able to analyze the inheritance patterns of desirable traits. Nevertheless, there have been some designed crossing plans and sufficient detailed collection of data in some programs to allow information on inheritance of traits to be assessed and published. In particular, the program at EMR under Elizabeth Keep published considerable information on inheritance of traits in the cultivated raspberry and some species material incorporated into that program

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HARVEY K. HALL, ET AL.

(Briggs et al. 1982; Keep 1968c, 1984a; Keep et al. 1977a,b). In addition, many studies on inheritance of traits were also carried out by Jennings and others at SCRI (Anthony et al. 1986; Jennings 1963b, 1964, 1979, 1982a,b; Jennings and Brydon 1989a; Jennings and Carmichael 1975a,b; Jennings and Jones 1986; Jennings and McGregor 1988; Jennings and Williamson 1982; Jennings et al. 1972; Jones and Jennings 1980; Williamson and Jennings 1986). Diallel crosses and other designed experiments in raspberry have been used by several raspberry breeding programs, with Ure (1960), Topham (1966), Øydvin (1968a), and Jennings (1971a) being forerunners in this area. In Poland, researchers used a 5  5 complete diallel experiment to investigate inheritance of primocane-fruiting traits, particularly earliness, seasonality and yield, fruit quality, and pest and disease resistance (Danek 1999). Useful information from this experiment was gained and published, but the information could have been considerably improved by measurement of some plant traits, harvest of each seedling, weighing and measuring harvested fruit samples, and postharvest evaluation of shelf life, fruit firmness, and ability to be handled through the fresh-market cool chain. In New Zealand, two experiments were carried out by HRNZ to investigate inheritance of traits in red raspberry and to identify superior clones for these traits (H.K. Hall, pers. observ.). The first experiment used ‘Haida’ as a test cross parent in crossing it with 36 other cultivars and selections, to investigate the ability of ‘Haida’ to impart adaptative as well as cane and production traits. Three replicates of five plants were planted from each cross, in a randomized block design. Traits measured or scored included: bud break, lateral number, length, strength and angle, growth habit, cane thickness, number and length, spininess versus spinelessness, fruit shape, estimated weight score and actual weight of fruit each harvest, estimated yield, yield, fruit color, ease of removal, receptacle length, shape, curvature, and hairiness (extent to which vascular traces of drupelets were retained after harvest), unattached collar length, depth of collar indent, estimated fruit firmness from two scorers, fruit brightness, fruit dustiness (presence of hairs on drupelets), fruit collar score, drupelet thickness, two scores of flavor, vigor, seasonality, and estimated and measured yield. Notes were also taken on the susceptibility of fruit to crumble or tear, fruit doubles, seediness, leafiness, fruit sunburn, plant color, response to pests and diseases, and other unusual traits. The second experiment was a 6  7 factorial design with 4 replicates of 4 plants for each cross. The parents selected were chosen to incorporate as much variability as possible in the entire experiment and when a cross segregated for spinelessness, a full replicate of both

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spineless and spiny segregants was included in the trial. The female parents were ‘Chilliwack’, ‘Haida’, ‘Kohatu’, ‘Meeker’, ‘Qualicum’, ‘Tulameen’, and a spineless selection from an open-pollinated population of red raspberry  R. parvifolius ((A257 [SCRI 795B10  OP]  R. parvifolius)  OP). Male parents included ‘Citadel’, ‘Sumner’, ‘Kaituna’, and three selections from the HRNZ raspberry breeding program, 92387QH-5 (A257  ‘Titan’), F79 (‘Marcy’  ‘Glen Isla’), and 88304ROC6 (‘Comox’  B257 [SCRI 7936F5  OP]). The same traits were recorded as for the test cross experiment, and two out of each four seedlings of each plot were assessed for Brix, titratable acidity, total anthocyanins, antioxidant activity, and total phenolics (Connor et al. 2005a,b). In both experiments, there was considerable variability and both populations produced transgressive segregants, which were outstanding plants with high yield, very large fruit, or other outstanding expressions of traits outside the range in variability represented by the parents. Yield expression was particularly high, and in at least one case a selection identified with very high yield was not obvious during the normal visual selection process. In further breeding, this clone has since proven to be an outstanding parent for high yield. In raspberry breeding, breeders typically produce between 10 and 100 crosses and grow 100 seedlings per cross each year, so that the total population size has varied between 700 and 10,000 seedlings or even up to 16,000 seedlings per year in a large breeding program. Smaller programs have sometimes limited breeding populations to one series per every 2 to 4 years to reduce the resources required to operate the program. Response to selection, R, is the amount of response per selection cycle. Time required, Y, to complete the cycle in raspberries is the sum of the time to achieve germination, the time from germination to field planting, the time from field planting to fruiting, and the time from fruiting to seed harvest of the next generation of breeding improvement. To maximize the rate of response to selection per year Ry ¼ R=Y ¼ h2 S/Y time elapsed for a full cycle should be minimized as it is difficult or impossible to increase the heritability, h2, or the selection differential, S. To maximize the rate of response to selection, these actions are advised: 1. Germinate seed immediately after harvest. 2. Prick up seedlings as soon as they have 1 to 2 true leaves and continue growing in a greenhouse.

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HARVEY K. HALL, ET AL.

3. Plant in the field as soon as screening for desirable traits is completed and plants are of sufficient size and have been hardened off (it is hoped within 6 to 10 weeks of germination). 4. Encourage plants in the field to grow by planting in good soil that has been cultivated to fine tilth, by optimizing water and fertilizer inputs, by ongoing control of weeds, by careful control of pests and disease, and by eliminating environmental hazards such as wind, heat, and cold as much as possible. 5. When fruiting is occurring, identify elite clones as soon as possible and used them for breeding when flowers are available for crossing. With primocane-fruiting cultivars, flowering and fruiting normally occurs in the first growing season. If sufficient flower and season is available, crosses can be completed immediately after selection. Often logistical or other factors limit the possibilities of reducing the life cycle to this short time frame, as discussed next. 1. Germination may be improved with some after-ripening of seed, seed treatment to scarify the endocarp, and stratification to supply winter chill requirements. In addition, seed will often germinate better in the springtime rather than in the autumn. 2. Some programs benefit from raising seedlings through the first growing season in pots, then planting dormant seedlings into the field where herbicides can be used to control weeds that would kill a young, actively growing seedling. 3. If selection is for ability to withstand heavy soils, cold, heat, other environmental challenges, or pests and disease, then growth may be reduced and the time to maturity increased. 4. With floricane-fruiting types, there is usually no flower available after selection so crossing cannot be completed until autumn if there is some primocane flowering or until the following growing season. D. Interspecific Hybridization Crosses between R. idaeus and R. strigosus are virtually completely fertile, and the European and North American red raspberry can be considered as variants of a single species. The heritage of almost all modern cultivars of raspberries from around the world include both these subspecies, which are now designated R. idaeus L. subsp. vulgatus and R. idaeus L. subsp. strigosus (but are referred to as R. idaeus and R. strigosus in this review to distinguish the two

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subspecies). More recent cultivars have utilized germplasm from other raspberry species from North America and particularly from Asia. Crosses between red raspberry cultivars and other Idaeobatus species vary in fertility and sometimes exhibit unilateral incompatibility, as in crosses with R. occidentalis, which only be successful only if the black raspberry is used as the female parent (Daubeny 1996; Zych 1965). Hybridization between red and black raspberry may result in highly infertile progenies or fully fertile purple raspberries (R. neglectus), which typically are crown-forming like R. occidentalis. Backcrosses may be made to red or black raspberries from these hybrids. Generations of crossing have been used to successfully transfer firmness from the black raspberry to the red raspberry in the EMR and SCRI programs and thornlessness from the red raspberry to the black and purple raspberry in the SCRI, Cornell, and New Zealand programs, resulting in the purple raspberry cultivar ‘Glencoe’ (Daubeny 1994; D.L. Jennings, pers. comm.; Shaddick 1988; C. Weber pers. comm.) and the black raspberry ‘Hortberry1’ EbonyTM (Boylen 2005; H.K. Hall, pers. comm.). Other Idaeobatus species have been successfully intercrossed with red raspberry, including: R. biflorus, R. cockburnianus, R. coreanus, R. crataegifolius, R. ellipticus, R. eustephanos, R. flosculosus, R. hawaiensis, R. hirsutus, R. innomatus, R. kuntzeanus, R. lasiocarpus, R. lasiostylus, R. leucodermis, R. mesogaeus, R. niveus, R. parvifolius, R. phoenicolasius (Plate 1B), R. pileatus, R. pungens Oldhami (¼ a yellow-fruited form of R. niveus), R. rosifolius, R. sachalinensis, R. spectabilis, R. sumatranus, and R. trifidus (Daubeny 1996; Finn et al. 2002; H.K. Hall, pers. comm.). Additional crosses have been made with R. deliciosus, R. odoratus, and R. parvifolius from the subgenus Anoplobatus; R. arcticus and R. stellatus from the subgenus Cylactis; R. trivialis and R. ursinus from the subgenus Rubus; and R. chamaemorus from the subgenus Chamaemorus (Daubeny 1996; Finn et al. 2002; H.K. Hall, pers. comm.). A wide range of valuable traits is available for the development of raspberry cultivars from these species (Table 3). Considerable variation exists in the fertility of the progenies from crosses between cultivated red raspberry and other Rubus species, from completely infertile, to an occasional plant in a cross with a few drupelets set, to some drupelets set in most plants, right through to full fertility. When a hybrid has been obtained, three approaches to further breeding have been pursued. Common approaches have been to backcross to cultivated types, to self the F1 selections, or to grow an open-pollinated population from the few drupelets set from almost infertile progenies.

148

R. hawaiensis A. Gray.

R. eustephanos Focke ex Diels. R. flosculosus Focke.

R. ellipticus Sm.

R. crataegifolius Bge.

R. coreanus Miq.

R. cockburnianus Hemsl.

R. chingii Hu.

Subgenus Idaeobatus R. biflorus Buch.

Species

High yield via high fruit numbers per lateral; condensed fruit ripening; erect habit; cane disease resistance, strong vigor Very large fruit, high drupelet number per fruit, heat and high humidity tolerance, dark red to purple fruit

Very high drupelet numbers per fruit, vigorous

Low chilling requirement, resistance to drought, high temperature, leaf spot, cane spot Fruit size, flavor and quality, upright growth, spinelessness, widely used in Chinese medicine High yield via high fruit numbers per lateral, ease of harvest (plugging), late-ripening floricane fruit Resistance to aphids (Amphorophora idaei), cane blight, spur blight, cane Botrytis, cane spot, cane beetle, powdery mildew, leaf spot, foliar disease, root rot, fruit rot, extremely early fruiting, high vigor, black, red, apricot or yellow color, high productivity Firm fruit with a bright, non-darkening red color; early ripening floricane fruit; resistance to fruit rot, cane and fruit Botrytis, cane midge, cane beetle, root lesion nematode; long shelf life, suitability for transportation, strong laterals, productive, excellent set, suitability for juicing and wine making Extreme vigor, nitrogen fixation, wine making, juice

Traits

Table 3. Species successfully used in crossing with red raspberry cultivars.

Morden et al. 2003

Daubeny 1996; Finn et al. 2002

Becking 1979; Ansari and Nand 1987; Finn et al. 2002 Finn et al. 2002

Keep 1984c; Hong et al. 1986; Isaikina and Kichina 1988; Daubeny 1996; Finn et al. 2002

Keep et al. 1977b; Jennings 1983b; Daubeny 1996; Finn et al. 2002

Daubeny 1996; Wei-Lin et al. 2002 Keep 1984c; Daubeny 1996

Daubeny 1996

References

149

R. leucodermis Douglas ex Torr. & A. Gray. R. mesogaeus Focke. R. niveus Thunb.Syn. R. Albescens Roxb., R. distans D. Don., R. lasiocarpus Sm., R. pauciflorus Wall. ex Lindl., R. pinnatus D. Don, R. rosaeflorus Roxb.

R. lasiostylus Focke.

R. kuntzeanus Hemsl.

R. innominatus S. Moore

R. idaeus R. illecebrosus Focke.

R. strigosus

R. hirsutus Thunb.

Large fruit, high drupelet number per fruit, heat and high humidity tolerance, resistance to variable winter temperatures, attractive bright red fruit, high Vitamin C Phytophthora root rot resistance, early primocane fruiting, vigor, resistant to Aphids High vigor, root rot resistance Primocane fruiting, heat and humidity tolerance, resistant to variable winter temperatures, leaf and cane disease, excellent set, large fruit, high drupelet number per fruit Phytophthora root rot resistance, early primocane fruiting, vigor, late ripening, heat and humidity tolerance, resistant to variable winter temperatures, high productivity, excellent set, diversity of colors and flavors, large fruit, erect plant habit Low chilling requirement; resistance to drought, high temperature, leaf spot, cane spot, cane beetle Large fruit size; ease of harvest; fruit cohesiveness, high number of drupelets per fruit, disease free foliage Productive, excellent fruit size, never reported to have RBDV, strong vigor, earlier fruiting, later budbreak Resistance to cane Botrytis, cane blight, cane midge Heat and humidity tolerance, resistance to cane and leaf disease, cane Botrytis, spur blight, fruit rots, erect growth habit, fruit firmness, good flavor, large number of fruit per lateral, some primocane fruit, black fruit, low chill adaptation

(continued )

Keep 1984c; Daubeny 1996; Finn et al. 2002 Ourecky and Slate 1966; Finn et al. 2002, 2003 Finn et al. 2002 Daubeny 1996; Finn et al. 2002

Daubeny 1996

Finn et al. 2002

Finn et al. 2002 Keep 1961; Hall pers. observ.

Finn et al. 2002

Finn et al. 2002; Wei and Payne 2002; Hall pers. observ.

150

R. trifidus Thunb.

R. sumatranus Miq.

R. sachalinensis H. Lev. R. spectabilis Pursh.

R. pinafaensis Levl. & Van. R. pungens Oldhamii (Miq.) Maxim. Syn. R. oldhamii R. rosifolius Sm.

R. pileatus Focke.

R. phoenicolasius Maxim.

R. parvifolius L. Syn. R. triphyllus Thunb.

R. occidentalis L.

Species

Table 3. (Continued ).

Jennings 1983b; Daubeny 1996; Hall pers. observ. Finn et al. 2002 Yeager and Meader 1958; Daubeny 1996 Finn et al. 2002; Hall pers. observ. Finn et al. 2002 Daubeny 1996; Finn et al. 2002

Early ripening floricane fruit, winter hardiness, resistance to spur blight, yellow fruit color

Very high drupelet number per fruit, adapted to high temperatures, upright canes, cane disease resistance 4x, cold hardy, strong vigor, large drupelet size, excellent flavor and color Both early floricane and early primocane ripening fruit; condensed fruit ripening; fruit with a bright, non-darkening, red color; ease of harvest; resistance to root rot, aphids (Amphorophora agathonica), erect growth Large fruit, very high drupelet number per fruit, Phytophthora resistant, repeat flowering Large fruit, spineless or spiny, leaf and cane disease resistant, vigorous, yellow or black fruit

Finn et al. 2002; Hall pers. observ.

Finn et al. 2002

Daubeny 1996; Hall pers. observ.

Daubeny 1996; Finn et al. 2002

Daubeny 1996; Langford and Snelling 1997; Weber 2003

References

Resistance to aphids (Amphorophora idaei), bud moth (Heterocrossa rubophaga Dugdale), leaf rollers, cane beetle, two-spotted spider mite, fruit rot; firm fruit; late-ripening floricane fruit, heat and humidity tolerance, resistant to variable winter temperatures, cane disease resistant Low chilling requirement; resistance to drought, high temperature, leaf spot, cane spot, root rot, cane and leaf disease, some tolerance to variable winter temperatures, productive, vigorous, good fruit size, a range of fruit colors, shiny fruit, two spotted mite resistance Resistance to cane beetle, powdery mildew, root rot, insect attack, birds, very sticky plant Resistance to cane blight, cane midge, cane Botrytis, spur blight, fruit rot, root rot; fruit flavor Large tasty fruit; medium-high drupelet number

Traits

151

R. ursinus (Cham. & Schltdl.)

Subgenus Rubus R. trivialis Michx.

Subgenus Chamaemorus R. chamaemorus L.

Subgenus Cylactis R. arcticus L. R. stellatus Sm. R. arcticus ssp stellatus.

R. parviflorus Nutt.

Subgenus Anoplobatus R. deliciosus Torr. R. odoratus L.

Early ripening, resistant to heat and high humidity, variable winter temperatures Outstanding fruit quality, productive, excellent fruit size, easy to cross due to dioecy, bridge parent production, limited value for raspberries

High ascorbic acid content winter hardiness, flavor, growth characteristics, spinelessness

Early-ripening primocane fruit; good flavor; aroma; winter hardiness Aroma; winter hardiness

‘‘Tree’’ growth habit; self-supporting canes; drought adapted, cold hardy Early primocane ripening; self-supporting canes; resistance to raspberry midge, cane blight Large, well formed raspberry-like fruit, genetic diversity

Finn et al. 2002

Finn et al. 2002

Daubeny 1996

Finn et al. 2002 Daubeny 1996

Daubeny 1996

Daubeny 1996 Finn et al. 2002

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In theory, it may be most advantageous to begin backcrossing to the cultivated types from F1, selections but this practice may be outperformed by selfing the F1 selections or collecting open-pollinated seed and growing an F2 generation, as practiced by Keep (1961) and Jennings (1963a) in early breeding populations grown at EMR and SCRI respectively and by Danek in Poland (Briggs et. al. 1982). In the F2 generation, full fertility may be restored in some seedlings, and it is also frequently possible to select plants showing good expression of the desired trait being introgressed from the wild species (C.E. Finn, pers. comm.; H.K. Hall, pers. observ.). When a fertile selection from F2 progenies is backcrossed to the red raspberry, fertility is frequently higher than in BC1 populations, and in some cases full fertility among BC populations is not restored even in the BC3 generation. Use of species in generating new diversity and for introgression of desirable traits has frequently been observed to result in new, unexpected outcomes. It is worthwhile to carry out this sort of germplasm enhancement with the use of new species even if it is only for broadening the germplasm base among the breeding material. For example, the use of a non–primocane-fruiting clone of R. spectabilis in breeding at EMR resulted in the selection of earlier primocane-fruiting selections. In New Zealand, use of a very-latefruiting clone of R. niveus (Fig. 23) resulted in the F2 of the earliest selection among all raspberry populations grown (H.K. Hall, pers. observ.; Keep 1984b). Use of that selection for further breeding resulted in shifting production farther forward by 1 week into the springtime. Species hybrids frequently exhibit considerable hybrid vigor, with F1 hybrids of R. niveus, R. parvifolius, and R. occidentalis with red raspberry being considerably more vigorous than either parent. Use of these F1 hybrids in further breeding generally results in restoration of vigor similar to the parental clones, although sometimes increased vigor is imparted to the progenies. F2 progenies may also show inbreeding depression, but use of lower-vigor selections in further breeding usually results in restoration of normal vigor if outcrossing is used. E. Inheritance Patterns A wide range of traits have been investigated in red raspberry and the inheritance of many of these have been analyzed, particularly in the work of Jennings at SCRI and Keep at EMR (Ourecky 1975a). Simply inherited traits have been recognized and given symbols to associate

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Fig. 23. Leaves and fruit Rubus niveus. (photo by H.K. Hall).

with them (Table 4). There are also rare cases where a single gene, such as gene L1 , affects multiple traits (Jennings 1979). Many other traits are quantitatively inherited and are not associated with any major genes. For example, genetic control of yield components, color of both plant and fruit, quality, flavor, aroma, and vigor are under multigenic control. These traits have been listed in Table 5. Further traits are associated with wild Rubus species and are promising for use in breeding new cultivars of raspberries (Table 6).

V. BREEDING FOR SPECIFIC CHARACTERS A. Adaptation The natural range of Rubus idaeus in Asia through to Europe and Rubus strigosus in North America is considerably less than the range of commercial cultivation of red raspberries around the northern hemisphere. In addition, commercial cultivation of raspberries has spread

154

Dominant gene for expression of leaf spot virus angular lesion symptoms

Ls

gr H

Sturdy dwarf Crumpled dwarf Frilly dwarf Associated genes controlling sex: FM hermaphrodite, Fmm female plant, ffM male plant, ffmm neuter flower Grotesque flower structure Hairy or pubescent cane confers Botrytis and Didymella avoidance/resistance; associated with susceptibility to cane spot, yellow rust, and powdery mildew

Pink flowers/white flowers Sterility (linked with mildew resistance) Waxy cane/lack of bloom on cane; Elsinoe avoidance Accessory buds Branched canes Pigmented growth Normal/pale green leaf

Gene effect

d1 d2 ðdwÞ d3 d4 d5 (fr) F, M

Plant Characters An/an ax4 B/b Bd1 , Bd2 Br1 Br2 C Ch1 =ch1 ðG=gÞZ

Gene symbol

Table 4. Genes identified in Rubus.

idaeus

idaeus idaeus

idaeus idaeus idaeus idaeus

idaeus idaeus coreanus, idaeus idaeus coreanus idaeus idaeus

Rubus species

Keep 1972 Crane and Lawrence 1931; Haskell 1960a Keep 1968c, 1972; Keep et al. 1977a, 1977b, 1979; 1980b; Knight 1962; Knight and Keep 1966; Jennings 1982a, 1982d; Jennings and Brydon 1989a, 1989b; Jennings and McGregor 1988; Jennings and Williamson 1982; Williamson and Jennings 1992 Jones and Jennings 1980

Daubeny 1996 Keep et al. 1980b Jennings 1962; Keep 1964, 1968c Jennings 1979; Keep 1968b, 1969a Keep et al. 1977b, 1977a, 1980b Crane and Lawrence 1931 Haskell 1960a; Keep 1968c; Lewis 1939, 1940 Jennings 1967a; Keep 1969b Keep 1969b Knight et al. 1959 Crane and Lawrence 1931

References

155

idaeus idaeus idaeus idaeus idaeus idaeus idaeus idaeus idaeus idaeus idaeus idaeus occidentalis

Dominant spine-free cane, eglandular cotyledons

Suckering When homozygous epistatic to Sk1sk1 Normal/simple leaf Incompatibility Self-fertility (no pollen reaction) Self-compatibility Female sterile, obtuse foliage Male sterile, normal leaf Sepaloid Sterility Enables synthesis of sophorose Tip rooting

Pollen tube inhibitor Lethal affecting H:h segregation Whorled receptacle Lethal affecting S:s segregation Lethal affecting T:t segregation Green/red hypotocotyl Enables synthesis of sambubioside

SfW

sk1 sk2 ska Sl/sl S1 S2 ðS1 S2 Þ Sf ðSf Þ Sfert ðSf ðSf ÞÞ sx1 ðf Þ sx2 ðmÞ sx3 ðdÞ sx4 So Tr

wðS5 Þ wh Wr ws wt X/x Xy

idaeus idaeus idaeus idaeus idaeus idaeus idaeus

idaeus

Spiny, glandular cotyledons/spineless, eglandular cotyledons, confers reduced Botrytis, cane blight, and spur blight in ‘Glen Moy’, ‘Glen Prosen’

(continued )

Rietsema 1939 Barritt and Torre 1975; Jennings and Carmichael 1980 Haskell 1960a; Jennings 1962, 1971c, 1983a, 1995; Keep 1968c, 1972; Keep et al. 1977b, 1979; Knight and Keep 1964 Jennings 1993; Jennings and Brydon 1990 Knight and Keep 1960 Knight and Keep 1960 Jennings 1967b Keep 1968a Keep 1968a, 1972 Keep 1985; Keep et al. 1984 Crane and Lawrence 1931 Crane and Lawrence 1931 Haskell 1960a; Keep 1964, 1972 Daubeny 1996 Jennings and Carmichael 1980 Crane and Lawrence 1931; Knight and Keep 1960 Øydvin 1968b Jennings 1967b Jennings 1977 Jennings 1967b Jennings 1967b Haskell 1960a; Lewis 1939 Jennings and Carmichael 1980

idaeus idaeus

S/s

no R

Jones and Jennings 1980

idaeus

Dominant gene for expression of leaf mottle virus angular lesion symptoms Dwarf, probably ¼ d1d2 Enables synthesis of rutinoside

Lm

156 idaeus

idaeus

Resistance to A. rubi strain 2

Y Ys Ycor AB

A2

A1

pptt fruit yellow, spines green, Ptt fruit apricot, spines green Yellow fruit Suppresses gene Y Yellow fruit AB resistance to Amphorophora rubi: probably identical to AK4a Resistance to A. rubi strains 1 and 3

t

phoenicolasius phoenicolasius coreanus idaeus

idaeus

idaeus idaeus

Miniature fruit PT fruit red, spines dark to base, ppT fruit red, spines tinged

l2 P

Rubus species

R. occidentalis R. occidentalis R. occidentalis idaeus idaeus idaeus idaeus

Gene effect

Fruit color black Fruit color apricot Fruit color purple Crumbly fruit (semi-fertility) Spine color intensifier/apricot colored fruit Yellow fruit (pleiotropic effects on vegetative traits) Large fruit and calyx as in ‘Glen Garry’, confers resistance to Botrytis, is unstable

Fruit Characters BlBlT BlBltt BlblT cr I i L1

Gene symbol

Table 4. (Continued ).

Keep and Parker 1977; Keep 1984a, 1989; Keep et al. 1981; Knight et al. 1960; Knight and Keep 1963; Jennings 1983a Keep 1984b, 1989; Keep and Parker 1977; Keep et al. 1981; Knight et al. 1960; Knight and Keep 1963; Jennings 1983d;

Britton et al. 1959 Britton et al. 1959 Britton et al. 1959 Jennings 1967b Keep 1984c Keep 1984c Jennings 1966a, 1979, 1986b, 1991; Jennings and Carmichael 1975b; Jennings et al. 1991 Jennings 1966b Crane and Lawrence 1931; Haskell 1960a; Jennings and Carmichael 1980; Øydvin 1968b; Britton et al. 1959; Crane and Lawrence 1931; Jennings 1963a, 1967a Jennings and Carmichael 1975a Jennings and Carmichael 1975a Jennings and Carmichael 1980 Baumeister 1961

References

157

Ourecky 1975b Keep 1989

idaeus

idaeus idaeus idaeus idaeus idaeus idaeus idaeus

Resistance to the common strain of RBDV

Immunity to Arabis mosaic rirus Immunity to raspberry ringspot virus Immunity to tomato black ring virus Resistance to Pucciniastrum americanum Resistance to powdery mildew: Sphaerotheca macularis Resistance to powdery mildew Resistance to yellow rust, Phragmidium rubi-idaei

Bu

Iam Irr Itb Pa Sp1Sp2

Z

Original symbol or other symbol used for this trait in brackets.

sp3 Yr

Keep 1989; Keep et al. 1980b Keep 1989; Keep et al. 1980b Daubeny 1966; Daubeny and Stary 1982; Jennings et al. 1991; Keep 1989 Jennings 1980, 1987; Jennings and Jones 1989; Jennings et al. 1991; Jones et al. 1982, 1988; Keep 1989; Jennings 1964 Jennings 1964 Jennings 1964 Jamieson and Nickerson 1999 Keep 1968c; Keep et al. 1977b

Keep 1989; Keep et al. 1980b, 1984

Keep 1989; Knight et al. 1960 Keep 1989; Knight et al. 1960 Keep 1989; Knight et al. 1960 Keep 1989; Knight et al. 1960 Keep 1989; Knight et al. 1960 Keep 1989; Knight 1962 Keep 1989; Knight 1962 Keep and Parker 1977; Keep et al. 1980b, 1981, 1982; Knight et al. 1972 Daubeny 1996; Knight et al. 1972

coreanus coreanus idaeus

idaeus

occidentalis

idaeus idaeus idaeus idaeus idaeus idaeus idaeus occidentalis

Disease and Pest Resistance Resistance to A. rubi strains 1, 2, 3, 4 Acor1 Resistance to A. rubi strain 2 Acor2 Resistance to Amphorophora agathonica Ag1  Ag3

AK4a ðAB?Þ

Resistance to A. rubi strains 1, 2, 3, 4 possibly identical to A10 Resistance to A. rubi strains 1, 2, 3, 4

AL503

A. rubi strain 1 A. rubi strain 2 A. rubi strain 1 A. rubi strain 1 A. rubi strain 1 A. rubi strains 1, 2, 3, 4 A. rubi strains 1, 2, 3, 4 A. rubi strains 1, 2, 3, 4

Resistance to Resistance to Resistance to Resistance to Resistance to Resistance to Resistance to Resistance to

A1 A3 A 3 ; A4 A5 A6 A7 A8 A9 A10

158

Light soils

Subtropical and tropical conditions Tunnel production

Hot, humid environments

Mild temperate conditions and warmer winters

Variable winter temperatures

Adaptation Hardiness for coldest regions

Characteristic

Chilliwack, Glen Ample, Glen Lyon, Isabel, Tulameen Cuthbert, Puyallup, Skeena, Tadmor

Summit

Bonanza, Chilliwack, Driscoll cultivars (including Gloria and Isabel), Marcy, Motueka, Moutere, Qualicum, Tadmor, Waiau Citadel, Dormanred, Dorsett, Mandarin, Sonoma, Southland, Van Fleet

Arbat, Aborigen, Birjusinka, Boyne, Chief, Festival, Geyser, Gordost Rossii, Izobilnaya, Jenkka, Killarney, Kirzhach, Latham, Lazarevskaya, Madawaska, Malakovka, Maroseika, Meteor, Muskoka, Newburgh, Nordic, Nova, OAC Regency, Ottawa, Patricia, Pequot, Peresvet, Redbrook, Skromnitsa, Souris, Stolicnaya, Tarusa, Trent, Ville. Cherokee, Citadel, Pocahontas, Reveille, Sentry, Scepter

Cultivar

Species

R. idaeus

R. hirsutus, R. innominatus, R. niveus, R. occidentalis, R. parvifolius, R. pileatus, R. sumatranus, R. trivialis R. ellipticus, R. hawaiensis, R. illecebrosus, R. rosifolius, R. sumatranus

R. hirsutus, R. innominatus, R. parvifolius, R. strigosus, R. trifidus, R. trivialis R. parvifolius, R. pileatus

R. coreanus, R. crataegifolius, R. deliciosus, R. sachalinensis, R. strigosus

Table 5. Idaeobatus cultivars and species with identifiable characteristics.

Hall pers. observ.; Ourecky 1975a;

Hall pers. observ.

Finn et al. 2002; Hall pers. observ.

Brooks and Olmo 1944, 1951, 1957; Finn et al. 2002; Hall pers. observ.; Ourecky 1975a;

Brooks and Olmo 1950; Finn et al. 2002; Hall pers. observ.

Finn et al. 2002; Hall pers. observ.; Ourecky 1975b

Brooks and Olmo 1951; Daubeny 1994, 1995a; Finn et al. 2002; Hall pers. observ.; Jamieson 2004; Kichina 2004; Luby et al. 1991; Ourecky 1975a; Palonen and Buszard 1997; Palonen 1999b; Zatylny et al. 1996;

References

159

Primocane fruiting

Many fruits per lateral

Abrikosovaya, Aezusmuna, Alice, Alkoopina, Amity, AnnaMarie, Anne, Ariadne, Augustred, Augusta, Autumn Bliss, Autumn Britten, Autumn Byrd, Autumn Cascade, Autumn Cygnet, Avgustina, Avgustovskoe Chudo, Babe Leto, Babe Leto2, Brianskaya Yubileinaya, Bogong, Boheme, Bountiful Giant, Brice, Brilliantovaya, Carmen, Caroline, Chinook, Comtesse, Deborah, Dinkum, Driscoll cultivars, Durham, Elegantnaya, Esenna Pozlata, Esther, Evraziya, Fall Gold, Fallbrook, Fallred, Favorite, Galante, Gerakl, Gloria, Godiva, Heritage, Himbotop, Hollins, Holyoke, Indian Summer, Isabel, Jaclyn, Joan Irene, Joan J, Joan Squire, Joe Mello, Johnson Everbearing, Josephine, Kalashnik, Krupna Dvorodna, Lawrence, Lloyd George, Lyulin, Marcy, Nadeznaya, Nedosyagamaya, Nordic, Oranzhevoe

Canby, Chilliwack, Durham, Esquimalt, Fertodi Karmin, Fertodi Venus, Heritage, Skeena, Viking Glen Clova, Malling Augusta, Malling Joy, Malling Leo

Latham, Marcy

Drought resistance

Growth Habit Erect cane

Cascade Bounty, Cascade Delight, Fairview, Malling Enterprise, Malling Exploit, Newburgh, Sumner,

Heavy soils

R. arcticus, R. idaeus, R. illecebrosus, R. niveus, R. odoratus, R. stellatus, R. strigosus

R. cockburnianus, R. innominatus

R. cockburnianus, R. crataegifolius

R. strigosus

R. idaeus, R. parviflorus, R. spectabilis, R. odoratus

(continued )

Daubeny 1994; Finn et al. 2002; Hall pers. observ; Keep and Parker 1977; Keep et al. 1981; Ourecky 1975a Bojcheva and Domozetova 2004; Brooks and Olmo 1944, 1946, 1947, 1949, 1951, 1954, 1956, 1964, 1968, 1972, 1974; 1978, 1982; Daubeny 1991, 1994, 1997a, 1999, 2000, 2004, 2006a; Kazakov 2006; Ourecky 1975a

Daubeny 2004; Hall pers. observ.; Ourecky 1975a

Brooks and Olmo 1956, 1962; Finn et al. 2002; Hall pers. observ.; Moore 2004, 2006a, 2007; Ourecky 1975a Ourecky 1975a

160

Heterozygous spiny/spineless (Ss)

Spinelessness Homozygous spinelessness (ss)

Accessory buds

Characteristic

Table 5. (Continued).

Autumn Cygnet, Benefis, Brice, Esquimalt, Georgia, Glen Ample, Glen Coe, Glen Doll, Glen Fyne, Glen Garry, Glen Lyon, Glen Moy, Glen Prosen, Glen Rosa, Glen Shee, Glen Yarra, Joan Irene, Joan J, Joan Squire, Kaituna, Malling Minerva, Marcela, Motueka, Poranna Rosa, Stolicnaya, Waimea Aspiring, Beskid, Chilliwack, Clutha, Comox, Dinkum, Esther, Fertodi Venus, Glen Clova, Glen Esk, Glen Isla, Glen Magna, Josephine, Kohatu, Malling Delight, Malling Leo, Malling Orion, Moutere, Octavia, Okawa,

Chudo, Pokusa, Polana, Polesie, Polka, Poranna Rose, Pathfinder, Perron’s Red, Prelude, Princess, PS-1049, PS-1703, Purple Autumn, Red River, Redwing, Romy, Rossana, Rubinovoe Ozherele, Ruby, Scepter, Sensation, Sentyabriskaya, September, Shapka Monomaha, Snegirek, Sonoma, Southland, Stonehurst, Summit, Sweetbriar, Tennessee Autumn, Terri Louise, Tola, Trailblazer, Wilhelm, Willamette, Yantarnaya, Zarya Vecheriyaya, Zeva Herbsternte, Zolotaya Osen, Zolotje Kupola, Zuravlik Glen Clova, Lloyd George

Cultivar

R. idaeus Burnetholm

R. idaeus

R. idaeus

Species

Daubeny 2004, 2006a; Hall pers. observ.; Jennings 1988

Daubeny 1995a, 1997a, 2004, 2006a; Haskell 1960a; Jennings 1982b, 1982c, 1988, 1995; Shaddick 1988

Jennings 1988; Keep 1969b

References

161

Cane midge, Resseliella Theobaldi

Mite resistance

Amphorophora agathonica

Insect Resistance Amphorophora idaei (formerly thought to be identical to A. rubi, blackberry specific species)

Spines reduced to cane base

Bearing other genes for spinelessness

Autumn Bliss, Autumn Britton, Autumn Byrd, Autumn Cascade, Autumn Cygnet, Autumn Treasure, Beskid, Canby, Carnival, Creston, Glen Ample, Glen Doll, Glen Fyne, Glen Garry, Glen Lyon, Glen Magna, Glen Rosa, Glen Shee, Julia, Lloyd George, Malling Delight, Malling Gaia, Malling Joy, Malling Juno, Malling Landmark, Malling Leo, Malling Minerva, Malling Orion, Miranda, Mitra, Octavia, Polana, Rideau, Rucami, Rumilo, Rusilva, Rutrago, Trent, Valentina Algonquin, Chemainus, Chilliwack, Clutha, Comox, Cowichan, Esquimalt, Haida, Kitsilano, Liberty, Malahat, Nootka, Qualicum, Royalty, Saanich, Skeena, Tulameen Milton, Newburgh, Preussen, Pyne’s Royal, Viking Norfolk Giant, Malling Landmark, Phoenix, Muskoka

Boheme, Chemainus, Chilliwack, Comox, Cowichan, Creston, Haida, Nootka, Qualicum, Saanich, Skeena, Tulameen

Selwyn, Skeena, Tadmor, Terri Louise, Tulameen, Valentina, Waimac Gold, Wakefield Spineless Willamette, Framita

R. crataegifolius, R. flosculosus, R. odoratus, R. parviflorus, R. phoenicolasius

R. idaeus

R. idaeus

R. coreanus, R. idaeus, R. occidentalis, R. strigosus,

R. parviflorus

(continued )

Keep 1989; McNicol et al. 1983; Williamson and Hargreaves 1976

Ourecky 1975a

Brooks and Olmo 1978; 1983; Daubeny 1973; 1978; 1991, 1994, 1995b, 1997a, 1999, 2002a, 2004, 2006a; Keep 1989

Daubeny 1991, 1994, 1995a, 2000; 2004, 2006a; Keep 1989; Knight 2002b; Ourecky 1975a

Daubeny 1997a; Jennings and Brydon 1990; Jennings and Ingram 1983 Brooks and Olmo 1958; Daubeny 1978, 1987a; Daubeny and Kempler 1995; Kempler et al. 2006

162

Firmness

Small size

Fruit Characters Large size Gene L1

Bud moth, Heterocrossa rubophaga Raspberry beetle: Byturus tomentosus

Characteristic

Aborigen, Anfisa, Arabeska, Arbat, Birusinka, Caroline, Cascade Delight, Chemainus, Deborah, Driscoll Maravilla, Esquimalt, Fertodi Aranyfurt, Fertodi Venus, Fertodi Zenit, Glen Ample, Glen Garry, Glen Magna, Glen Moy, Glen Prosen, Gordost Rossii, Gradina, Hilton, Himbotop, Izobilnaya, Kalashnik, Kirzhach, Krasa Rossii, Krupna Dvorodna, Lauren, Malahat, Malling Delight, Madawaska, Marcy, Maroseika, Mirage, Nedosyagamaya, Newburgh, Patricia, Pokusa, Preussen, Pyne’s Royal, Reveille, Rideau, Royalty, Ruby, St Walfried, Stiora, Sirenevyui Tuman, Stoleshnik, Stolicnaya, Tadmor, Taganka, Tarusa, Terentii, Terri Louise, Titan, Tulameen, Waiau, Zhiolji Gigant Asker (Winkler’s Sa¨mling), Bonanza, Chief, Haida, Latham, Viking Amity, Ariadne, Autumn Cascade, Benefis, Beskid, Bogong, Brice, Carmen, Caroline, Cascade Delight, Chemainus, Chilliwack, R. crataegifolius, R. niveus, R. occidentalis R. crataegifolius, R. idaeus, R. occidentalis, R. pileatus

R. hirsutus, R. idaeus, R. strigosus

R. cockburnianus, R. coreanus, R. kuntzeanus, R. phoenicolasius, R. thibetanus

Beskid

Species R. glaucus, R. occidentalis

Cultivar

Amethyst, Clyde, Columbian, Jewel, Munger, Royalty

Table 5. (Continued).

Leemans and Nannenga 1957; Ourecky 1975a Brooks and Olmo 1955, 1967, 1969, 1983; Daubeny 1991, 1994, 1995a, 1997a, 1999,

Brooks and Olmo 1946, 1967, 1968, 1983; Cormack and Woodward 1977; Daubeny 1994, 1995a; 1997a, 1999, 2002a, 2004; 2006a; Jennings 1995; Leemans and Nannenga 1957; Moore 2004; Ourecky 1975a

Daubeny 1994; Keep 1989

Hall pers. observ.; Wilde et al. 1991b

References

163

Early ripening

Good quality for IQF (Best quality) Good fresh quality

Strong skin strength Good (best) processing quality

Chinook, Coho, Cowichan, Dinkum, Driscoll cultivars, Earlysweet, Emily, Fertodi Rubina, Fertodi Zamatos, Frosta, Georgia, Glen Ample, Glen Garry, Glen Lyon, Glen Prosen, Glen Rosa, Glen Yarra, Glencoe, Gloria, Gradina, Heritage, Himbo Star, Hitra, Isabel, Jatsi, Joan Squire, Josephine, Kaituna, Kitsilano, Krupna Dvorodna, Laska, Lauren, Lewis, Malahat, Malling Augusta, Malling Gaia, Malling Joy, Meeker, New Hampshire, Octavia, PS-1049, PS-1703, Polka, Poranna Rose, Rutrago, Qualicum, Saanich, Star, Stiora, Summit, Tadmor, Tambar, Tulameen Chilcotin, Heritage, Isabel, Joan Irene, Joan Squire, Nootka, Nordic, Sweetbriar Boyne, Cascade Nectar,Z Cuthbert, Fertodi Venus, Glen Ample, Glen Clova, Glen Magna, Gradina, Julia, Madawaska, Malling Gaia, Malling Jewel, Malling Joy, Malling Leo, Mandarin, Marcy, Meeker, Motueka, Skeena, Sumner, Taylor, Thames, Veten, Waimea, Washington, Willamette Chemainus, Coho, Glen Doll, Meeker, Motueka, Ruvi, Tomo Driscoll Cultivars, Glen Ample, Isabel, Octavia, Tadmor, Tulameen Aita, Chief, Cascade Dawn, Early Red, Georgia, Glen Clova, Glen Moy, June, Malahat, Malling Juno, Malling Minerva, Malling Promise, Moutere, Ohau Early, Prelude, Reveille, Sunrise, Trent, Valentina R. idaeus, R. strigosus

R. idaeus, R. strigosus

(continued )

Daubeny 2006a; Kingston et al. 1990; Moore 2006a; Ourecky 1975a; Jennings 1982b;Taylor and Knight 2007

Daubeny 2000, 2002a, 2004, 2006a

Daubeny 1991, 1995a, 2006a; Hall pers. observ. Brooks and Olmo 1944, 1946, 1953, 1956, 1957, 1960, 1967, 1969; Daubeny 1994, 1995a, 2002a, 2004

2000, 2002a, 2004, 2006a; Hall pers. observ.; Ourecky 1975a

164

Apricot fruit Ptt Red heterozygote ppTt

Yellow fruit pptt

High drupelet number

Small drupelets Large drupelets (40 mg or more)

Late ripening

Characteristic

Cultivar

Cuthbert, Latham, Malling Leo, Tadmor, Taylor Heritage, Malling Jewel Boyne, Brandywine, Centennial, Chilcotin, Chilliwack, Comox, Glen Ample, Glen Prosen, Gradina, Lloyd George, Madawaska, Malling Delight, Newburgh, Puyallup, Qualicum, Scepter, Schonemann, Skeena, St Walfried, Tulameen, Willamette Cascade Delight, Centennial, Delmes, Haida, Krupna Dvorodna, Malling Admiral, Malling Delight, Malling Joy, Malling Promise, Meeker, Qualicum, Schonemann, Tulameen, Willamette Alkoopina, Anne, Better Homes and Gardens (Golden Willamette), Citria, Fallgold, Fertodi Aranyfurt, Forever Amber, Godiva, Golden Bliss (Allgold in England), Golden Queen (Golden Mutant of Cuthbert), Goldenwest, Goldie, Helkal, Honeyqueen, Kiwigold, New York Times (Golden Indian Summer), Poranno Rose, Yellow Antwerp Valentina, Varnes Amity, Autumn Bliss, Cayuga, Chilcotin, Cuthbert, Fairview, Glen Garry, Heritage, Honeyking, Indian Summer, June, Lewis, Lloyd George, Malling Delight, Marlboro,

Table 5. (Continued).

R. occidentalis R. phoenicolasius

R. trifidus, R. phoenicolasius

R. hirsutus, R. sumatranus

R. idaeus R. idaeus

R. idaeus

Species

Brooks and Olmo 1953, 1957, 1972, 1973, 1982; Daubeny 1991, 1994, 1997a, 1999, 2000, 2002a, 2004, 2006a; Fear 1999; Jennings and Carmichael 1975a; Kikas et al. 2002; Leemans and Nannenga 1957; Thomas 2000 Daubeny 2002a, 2006a Anthony 1916; Brooks and Olmo 1973; Daubeny 1997a, 2002a, 2006a; Knight and Keep 1958; Leemans and Nannenga 1957;

Hall pers. observ.; Moore 1993b, 1998

Ourecky 1975a Moore 1993b, 1998

Ourecky 1975a

References

165

Rhizopus fruit rot RBDV (common strain)

Disease Resistance Botrytis fruit rot Botrytis cinerea

Glen Isla, Glen Prosen, Meeker, Nootka Amethyst, Avon, Black Hawk, Boyne, Bristol, Burnetholm, Cayuga, Chief, Chilcotin, Citadel, Citria, Clyde, Columbian, Cowichan, Cumberland, Dormanred, Fairview, Getrudis, Glen Clova, Glen Magna, Glen Rosa, Golden Queen, Haida, Hailsham, Herbert, Heritage, Hilton, Jatsi, Jenkka, Killarney, Kiwigold, Korbfuller (Fillbasket), Krupna Dvorodna, La France, Latham, Lord Lamborne, Malling Admiral, Malling Augusta, Malling Delight, Malling Enterprise, Malling Exploit, Malling Gaia, Malling Jewel, Malling Joy, Malling M, Malling Minerva, Malling Orion, Malling Promise, Mandarin, Matsqui, Motueka, Moutere, Nootka, Novost Kuzmina, Octavia, Okawa, Pyne’s Royal, Ruvi, Schonemann, Selwyn, Sentinel, September, Star, Sumner, Tadmor, Valentina, Waiau, Waimea, Willamette

Benefis, Carnival, Chemainus, Chilliwack, Chinook, Cuthbert, Driscoll Cultivars, Glen Isla, Glen Prosen, Haut, Joan Irene, Kitsilano, Malling Jewel, Malling Minerva, Marwe, Matsqui, Meeker, Nootka, Octavia, Skeena, Tadmor, Tulameen, Vene

Meeker, Novost Kuzmina, Orrs Seedling, Red Antwerp, Sumner, Tadmor, Taylor, Viking, Willamette

R. leucodermis

R. crataegifolius, R. occidentalis, R. pileatus

(continued )

Barritt 1971; Barritt and Torre 1980; Brooks and Olmo 1970, 1978; Daubeny 1991, 1994, 1997a, 1999, 2004, 2006a; Daubeny and Pepin 1975b; Keep 1989; Keep and Knight 1986; Ourecky 1975a Daubeny et al. 1980 Daubeny 1994, 1995b, 1999, 2002a, 2004, 2006a; Hall pers. observ.

Swartz et al. 1998; Hall pers. observ.

166

Cane spot or Anthracnose (Elsinoe veneta)

Powdery mildew (Sphaerotheca macularis)

Spur blight (Didymella applanata)

Characteristic

Cultivar

Algonquin, Amber, Bristol, Carnival, Chilliwack, Citria, Dundee, Festival, Glen Lyon, Glen Rosa, Haida, Julia, Marcy, Malahat, Malling Admiral, Malling Gaia, Malling Landmark, Malling Leo, Marion, Nawojka, Newburgh, Ottawa, Preussen, Pyne’s Royal, Qualicum, Ruvi, Saanich, Southland, Star, Titan, Viking Allen, Chief, Chilcotin, Citria, Cumberland, Festival, Gatineau, Lawrence, Lloyd George, Madawaska, Malling Exploit, Malling Landmark, Malling Leo, Malling Orion, Malling Promise, Marcy, Meeker, Newburgh, Nootka, PS-1703, Puyallup, Qualicum, Rideau, Ruby, Southland, Star, Sumner, Taylor, Tulameen, Willamette Aita, Allegany, Alvi, Amethyst, Chief, Chilcotin, Chilliwack, Citria, Clutha, Clyde, Comox, Cuthbert, Esquimalt, Glen Clova, Haida, Heritage, Julia, Kostinbrodskaya, Lowden Purple, Malling Augusta, Malling Exploit, Malling Promise, Marcy, Meeker, Newburgh, Newman, Octavia, Ottawa, Pocahontas, Preussen, Pyne’s Royal, Ralitsa, Ranere, Rannaya Sladkaya, Rode Radboud, Southland, Sparkling Gem, Star, St Walfried, Sunrise, Taylor, Turner, Van Fleet, Viking

Table 5. (Continued).

R. biflorus, R. coreanus, R. glaucus, R. idaeus R. innominatus, R. kuntzeanus, R. niveus, R. phoenicolasius

R. coreanus, R. idaeus

R. idaeus, R. occidentalis

Species

Brooks and Olmo 1947, 1962, 1969, 1972, 1975, 1982; Daubeny 1994, 2002a, 2004, 2006a; Jennings and McGregor 1988; Keep 1989; Ourecky 1975a

Brooks and Olmo 1964, 1969, 1973; Daubeny 1991, 1994, 1995a, 2002a; Keep 1968c; Meland 1986; Ourecky 1975a; Pscheidt 2006

Brooks and Olmo 1973; Daubeny 1991, 1994, 1995a, 1997a, 1999, 2002a; Daubeny and Pepin 1974b, 1975b; Ourecky 1975a; Swait 1980

References

167

Cane Botrytis (Botrytis cinerea) Verticillium wilt (Verticillium albo-atrum) Root rot (Phytophthora species) (highly resistant)

Cane blight (Leptosphaeria coniothyrium) Leaf spot (Sphaerulina rubi)

Glen Rosa, Julia, Malahat, Malling Gaia, Malling Leo, Nawojka, Octavia, Vene Cayuga, Cuthbert, Glencoe, Marlboro, Ohta, Owasco, Seneca, Southland, Superlative, Syracuse, Red Antwerp, Willamette Algonquin, Amity, Anne, Asker (¼Winkler’s Sa¨mling), Augustred, Autumn Bliss, Boyne, Carnival, Caroline, Cascade Delight, Centennial, Chemainus, Cherokee, Chief, Chilliwack, Chinook, Citria, Cuthbert, Durham, Fairview, Frosta, Georgia, Glen Ample, Haida, Himbotop, Hitra, Killarney, Latham, Josephine, Marwe, Matsqui, Meco, Meeker, Newburgh, Nova, Pathfinder, Prelude, Puyallup, Rubaca, Sumner, Stiora, Stonehurst, Summit, Sunrise, Tambar, Taylor, Valentina, Wawi R. glaucus, R. idaeus, R. illecebrosus, R. parvifolius, R. spectabilis, R. strigosus, R. sumatranus

R. parvifolius, R. spectabilis, R. strigosus

(continued )

Daubeny 1994, 1995a, 1997a, 1999, 2004 Fiola and Swartz 1994; Keep 1989; Ourecky 1975a; Zeller 1936 Barritt et al. 1981; Bristow et al. 1988; Brooks and Olmo 1956; Daubeny 1991, 1997a, 2004; Keep 1989; Ourecky 1975b; Pattison and Weber 2005; Roen et al. 2002; Spiegler and Thoss 1993

Brooks and Olmo 1947, 1957, 1968, 1969, 1972, 1982; Daubeny 2002a; Keep 1989

Citadel, Citria, Dixi, Dormanred, Evans, Fertodi Rubina, Iskra, Mandarin, Marlboro, Pocahontas, Potomac, Ranere, Sparkling Gem, Southland, Star, Sunrise, Van Fleet

R. biflorus, R. coreanus, R. incisus, R. innominatus, R. inopertus, R. kuntzeanus, R. mesogaeus, R. morifolius, R. niveus, R. parvifolius, R. phoenicolasius, R. rosaefolius, R. wrightii

Brooks and Olmo 1972; Daubeny 1994, 2006a

Helkal, Julia, Pocahontas, Tomo

168

z

Suitable for liquor.

Soil-borne virus

Leaf spot

Late yellow rust (Pucciniastrum americanum)

Yellow rust (Phragmidium rubi-idaei)

Characteristic

Cultivar

Lloyd George, Malling Landmark

Boyne, Cayuga, Chief, Fillbasket, Glen Prosen, Herbert, Latham, Lewis, Lloyd George, Malling Leo, Malling Promise, Marcy, Meeker, Motueka, Moutere, Newburgh, Newman, Owasco, PS-1703, Puyallup, Ranere, Red Antwerp, Seneca, Sumner, Tadmor, Tahoma, Taylor, Waiau, Waimea, Washington, Willamette Caroline, Chilliwack, Comox, Deborah, Godiva, Josephine, Lawrence, Malling Joy, Malling Orion, Nova, Olympic, Pocahontas, Royalty, Ruby, Trailblazer Citadel, Pyne’s Royal

Table 5. (Continued).

R. biflorus, R. coreanus, R. innominatus, R. kuntzeanus, R. niveus, R. idaeus R. idaeus

R. occidentalis

R. leucodermis, R. occidentalis, R. parvifolius, R. spectabalis

Species

Ourecky 1975a

Daubeny 1991, 1994, 2000, 2002a, 2004; Ellis and Ellett 1981; Jamieson and Nickerson 1999; Luffman 1990 Ourecky 1975a

Brooks and Olmo 1944; Hall pers. observ.; Keep 1989;

References

2. RASPBERRY BREEDING AND GENETICS

169

Table 6. Traits associated with Rubus species suited for use in breeding raspberries. Species

Traits

Subgenus Idaeobatus R. biflorus Low chilling requirement; resistance to drought, high temperature, leaf spot, cane spot R. cockburnianus High yield via high fruit numbers per lateral; ease of harvest (plugging); late-ripening floricane fruit R. coreanus

R. crataegifolius

R. ellipticus

R. eustephanos R. flosculosus

R. hawaiensis

R. hirsutus

R. idaeus R. strigosus

Resistance to aphids (Amphorophora idaei), cane blight, spur blight, cane Botrytis, cane spot, cane beetle, powdery mildew, leaf spot, foliar disease, root rot, fruit rot; extremely early fruiting; high vigor; black, red, apricot, or yellow color; high productivity Firm fruit with a bright, nondarkening red color; early-ripening floricane fruit; resistance to fruit rot, cane and fruit Botrytis, cane midge, cane beetle, root lesion nematode; long shelf life; suitability for transportation; strong laterals, productive, excellent set; suitability for juicing and wine making Extreme vigor; nitrogen fixation; suitable for wine making, juice Very high drupelet numbers per fruit; vigorous High yield via high fruit numbers per lateral; condensed fruit ripening; erect habit; cane disease resistance; strong vigor Very large fruit; high drupelet number per fruit; heat and high humidity tolerance; dark red to purple fruit Large fruit; high drupelet number per fruit; heat and high humidity tolerance; resistance to variable winter temperatures; attractive bright red fruit High vigor; root rot resistance Phytophthora root rot resistance; resistant to aphids; early primocane fruiting, vigor,

References Daubeny 1996; Keep 1984b Daubeny 1996; Finn et al. 2002; Jennings 1983b; Keep et al. 1977b Daubeny 1996; Finn et al. 2002; Hong et al. 1986; Isaikina and Kichina 1988; Keep 1984b

Ansari and Nand 1987; Becking 1979; Finn et al. 2002

Finn et al. 2002

Daubeny 1996; Finn et al. 2002 Morden et al. 2003

Finn et al. 2002; Hall pers. observ.

Finn et al. 2002

Finn et al. 2002 Hall pers. observ.

(continued )

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Table 6. (Continued). Species R. illecebrosus

R. innomatus

R. kuntzeanus

R. lasiocarpus R. lasiostylus

R. leucodermis

R. mesogaeus R. niveus

R. occidentalis

R. parvifolius

Traits Primocane fruiting; heat and humidity tolerance; resistant to variable winter temperatures, leaf, and cane disease; excellent set; large fruit; high drupelet number per fruit Phytophthora root rot resistance; early primocane fruiting; vigor; late ripening; heat and humidity tolerance; resistant to variable winter temperatures; high productivity; excellent set; diversity of colors and flavors; large fruit; erect plant habit Low chilling requirement; resistance to drought, high temperature, leaf spot, cane spot, cane beetle Resistance to cane Botrytis, spur blight Large fruit size; ease of harvest; fruit cohesiveness; high number of drupelets per fruit; disease-free foliage Productive; excellent fruit size; never reported to have RBDV; strong vigor; earlier fruiting; later bud break Resistance to cane Botrytis, cane blight, cane midge Heat and humidity tolerance; resistance to cane and leaf disease, fruit rots; erect growth habit; fruit firmness; good flavor; large number of fruit per lateral; some primocane fruit; black fruit, low chill adaptation Resistance to aphids (Amphorophora idaei), bud moth (Heterocrossa adreptella Walker), leaf rollers, cane beetle, two-spotted spider mite, fruit rot; firm fruit; late-ripening floricane fruit, heat and humidity tolerance; resistant to variable winter temperatures; cane disease resistant Low chilling requirement; resistance to drought, high temperature, leaf spot, cane spot, root rot, cane and leaf disease; some tolerance to variable winter temperatures; productive; vigorous; good fruit size; a range of fruit colors, shiny fruit; two-spotted mite resistance

References Finn et al. 2002

Daubeny 1996

Daubeny 1996

Daubeny 1996; Finn et al. 2002; Keep 1984b Finn et al. 2002, 2003; Ourecky and Slate 1966 Finn et al. 2002

Finn et al. 2002 Daubeny 1996; Weber 2003

Daubeny 1996; Finn et al. 2002

Daubeny 1996; Hall pers. observ.

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Table 6. (Continued). Species R. phoenicolasius

R. pileatus

R. pinafaensis R. pungens Oldhami

R. rosifolius

R. sachalinensis

R. spectabilis

R. sumatranus

R. trifidus

Traits Resistance to cane beetle, powdery mildew, root rot, insect attack, birds; very sticky plant Resistance to cane blight, cane midge, cane Botrytis, spur blight, fruit rot, root rot; excellent fruit flavor Large tasty fruit; medium-high drupelet number Early-ripening floricane fruit; winter hardiness; resistance to spur blight Very high drupelet number per fruit; adapted to high temperatures; upright canes; cane disease resistance 4x, cold hardy, strong vigor; large drupelet size; excellent flavor and color Both early-floricane and earlyprimocane ripening fruit; condensed fruit ripening; fruit with a bright, nondarkening, red color; ease of harvest; resistance to root rot, aphids (Amphorophora agathonica); erect growth Large fruit; very high drupelet number per fruit; Phytophthora resistant; repeat flowering Large fruit; spineless or spiny; leaf and cane disease resistant; vigorous; yellow or black fruit.

Subgenus Anoplobatus R. deliciosus ‘‘Tree’’ growth habit; self-supporting canes; drought adapted, cold hardy R. odoratus Early primocane ripening; selfsupporting canes; resistance to raspberry midge, cane blight R. parviflorus Large, well-formed raspberry-like fruit; genetic diversity Subgenus Cylactis R. arcticus Early-ripening primocane fruit; good flavor; aroma; winter hardiness R. stellatus Aroma; winter hardiness

References Daubeny 1996; Hall pers. observ.; Jennings 1983b Finn et al. 2002

Daubeny 1996; Yeager and Meader 1958; Finn et al. 2002; Hall pers. observ. Finn et al. 2002

Daubeny 1996; Finn et al. 2002 Finn et al. 2002

Finn et al. 2002; Hall pers. observ. Daubeny 1996

Finn et al. 2002

Daubeny 1996

Finn et al. 2002

Daubeny 1996

Daubeny 1996

(continued )

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Table 6. (Continued). Species

Traits

Subgenus Chamaemorus R. chamaemorus High ascorbic acid content; winter hardiness, flavor; growth characteristics, spinelessness Subgenus Rubus R. trivialis Early ripening; resistant to heat and high humidity; variable winter temperatures R. ursinus Outstanding fruit quality, productive, excellent fruit size; easy to cross due to dioecy, bridge parent production; limited value for raspberries

References Finn et al. 2002

Finn et al. 2002

Finn et al. 2002

through temperate to subtropical regions around the southern hemisphere. Key to expanding this adaptive range has been new cultivar development, utilizing a narrow sample of germplasm from European and North American red raspberry germplasm as well as a range of accessions from wild raspberry and other Rubus species (Dale et al. 1993). Cultivar adaptation in very cold northern locations has been based on a few cultivars developed in the northeastern United States and southeastern Canada, and in northern and eastern Europe through to Siberia, northern China, and Korea. 1. Cold-hardiness. In high-latitude countries, cold winter temperatures may be the primary factor that defines where native Rubus spp. are located and where raspberry cultivars are adapted, as has been demonstrated with woody plants (George et al. 1974). Although the ability of plants to withstand cold winter temperatures is a complex trait, within the last decade there have been significant contributions to our understanding of cold tolerance. In addition, molecular genetics research with Arabidopsis has revealed mechanisms that may be similar to those in Rubus. Physiology of Hardiness. The annual growth cycle of raspberry has been thoroughly described by Jennings (1988) and Carew et al. (2000). Primocanes typically show a sigmoidal growth pattern beginning in spring and tapering off during summer (during August in the northern countries). As day-length shortens and temperature declines, plants

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enter a period of endodormancy, which corresponds to the period of flower induction in biennial-fruiting raspberries. In primocane-fruiting genotypes, flowers are induced and initiated earlier and dormancy is entered later. Cool temperatures have a major effect on dormancy induction and subsequently on its release. Although cultivars differ in their depth and duration of endodormancy, in cool northern climates, this period is most intense during October and November and diminishes during December (Carew et al. 2000). In Ithaca, New York, the chilling requirement to complete endodormancy is usually achieved by mid-December (Pritts et al. 1999). Five to 8 weeks of chilling temperatures are required, depending on the cultivar (Dale et al. 2003). Effective chilling temperatures have been assessed as < 7 C but > 0 C (Jennings et al. 1964), or below 8 C (Dale et al. 2003; Dale 2008). Endodormancy does not end abruptly but gradually as the percent bud break increases (White et al. 1998). In addition to the removal of dormancy, chilling advances flowering through vernalization (Carew et al. 2000). Following endodormancy, cold temperatures will prevent the growth of buds, whether on canes or roots, during the winter ecodormancy (Lang et al. 1987). Concurrent with the onset of endodormancy is the process of acclimation (hardening)—the increasing ability of plants to withstand freezing temperatures. As plants acclimate, major physiological changes take place; for example, water content of the canes is reduced and changes occur in content of sugars and starch (Jennings 1988; Jennings et al. 1972). Cultivar differences in hardiness may be correlated to the degree of these changes. Warmund and George (1990) found that bud moisture content of 10 cultivars was not clearly related to hardiness as measured by supercooling capacity or to lowtemperature exotherms. They speculate that due to the small size of flower bud primordia, whole-bud hydration level may be an insensitive measure of primordia supercooling capability. In studies in Finland, a closer relationship between water content and late winter bud hardiness was found in ‘Muskoka’ raspberry (Keina¨nen et al. 2006). Low water content in buds and shoots seemed to be necessary to retain the capacity for buds and shoots to reharden after mild temperatures. The bud base vascular tissue lost its hardening capacity earlier than floral primordia. Measurement of cultivar differences in water content does not appear to hold promise as an effective screening tool. Palonen and Linde´n (1999) hypothesized that late-winter-hardiness differences in cultivars may relate to different temperature requirements for growth. In Finland, winter injury most often occurs in late winter or early spring; in other locations, low

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temperatures in the fall are thought to be injurious (Daubeny 1987a; Linde´n et al. 1999). Carbohydrates, especially sucrose reserves, are important in raspberry winter survival (Linde´n et al. 1999). During acclimation in the fall, starch content declines and soluble sugars increase. Palonen (1999a,b) demonstrated that in winter, high concentrations of sucrose are found in the canes. In the buds, sucrose is present but often exceeded by glucose and fructose. Hardy raspberry cultivars were characterized by high concentration of soluble carbohydrates, sucrose, and a high ratio of sucrose to glucose þ fructose. The Palonen study substantiates the importance of carbohydrate reserves to winter survival in raspberries and provides an explanation for lack of hardiness following poor foliar health or partial defoliation caused by pests. Production practices that improve carbohydrate reserves should increase hardiness. Although hardier cultivars had higher soluble carbohydrate content after cold acclimation both in vitro and in vivo (Palonen et al. 2000), genotype differences may not be sufficient to facilitate seedling screening. In Latvia, winter survival of ‘Norna’ was improved by using tissue-cultured plants over those established from root suckers (Bite and Petrevica 2002). The authors did not give an explanation for this, but it may have related to increased carbohydrate reserves. Cold injury may occur in the fall, winter, or spring, during different physiological states of the plants, which complicates breeding for greater hardiness. Genotypes that acclimate early are less likely to be injured by cold temperatures in early fall. Genotypes that emerge from ecodormancy rapidly may be more likely to be injured after fluctuating winter temperatures or by freezing spring temperatures. A cultivar with a deep and prolonged dormancy is expected to be more winter hardy; ‘Chief’ is such a cultivar (Bailey 1948; Van Adrichem 1970). Daubeny (1996), in his comprehensive review of the brambles, stated that adaptation to low winter temperatures involves: (1) the ability to harden rapidly in the fall; (2) long rest or deep dormancy in order to avoid out-of-season bud activity caused by temperature fluctuations; (3) the ability to reharden if initial cold resistance is lost; and (4) late bud break. In accord with Daubeny’s first factor, Van Adrichem (1970) noted the importance of early cane maturity in cold-hardiness. Sa¨ko¨ and Hiirsalmi (1980) also found a positive correlation between winterhardiness and early growth cessation in the fall, although there were exceptions: genotypes that grew longer in the fall but still were hardy. Zatylny et al. (1996) found that the time of leaf drop and cessation of cane extension growth in the fall were not correlated with field survival. Recent studies, however, have indicated that changes in

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dormancy status have failed to explain differences in cultivar hardiness (Palonen and Linde´n 1999). Maximum hardiness is often attained after endodormancy is completed, and endodormancy and cold-hardiness may be physiologically unconnected (Palonen and Linde´n 1999, 2006). Palonen and Linde´n (1999) considered the retention of coldhardiness once attained and the capacity to reharden after a warm period to be crucial for the winter survival of raspberry. Plants must survive freezing temperatures for up to 4 months following endodormancy. They studied the relationship between dormancy status and deacclimation and the capacity of three cultivars to reacclimate. The cultivars differed in their depth of endodormancy (measured as the time to bud break) and also in the date that dormancy was deepest. Cultivar differences in cold-hardiness occurred January through April, which confirms observations that injury usually occurs in the spring in Finland. After deacclimating canes by exposure to 10 C for 3 days, canes and buds could be reacclimated with exposure to cool temperatures for 3 days; however, the least hardy cultivar, ‘Maurin Makea’, lost the capacity to reharden after January. In this study, maximum cold-hardiness occurred after the endodormancy was broken. The very hardy ‘Ottawa’ showed little response to warm deacclimation temperatures post-endodormancy and thereby retained its hardiness. These studies in Finland indicated that Daubeny’s (1996) third factor—the ability to reharden—is of great importance to winter survival, especially when coupled with a lack of physiologic response to deacclimating temperatures. Daubeny’s fourth factor—late bud break—may be related to a requirement for higher temperatures or a higher growing degree-day accumulation to initiate bud break and growth of laterals. Late-spring frost injury is uncommon, and the authors are unaware of published accounts identifying genotypes with tolerance to frost injury of flowers or shoots. Hardy Germplasm. Numerous studies have identified genotypes with enhanced cold tolerance (Table 7). However, results from one region must be applied to those of another with an understanding that the expression of the trait has a strong interaction with environment. The most comprehensive evaluation of genotypes was undertaken in Oregon by Hummer et al. (1995). They collected cane samples in January, acclimated them for 27 days at 2 C, and then tested their response to freezing temperatures as low as 40 C. In general, raspberries were found to be hardier than blackberries, and lower

176

Honeyking, Chief, Latham Festival Boyne SK Red Mammoth, SK Red Bounty Boyne, Killarney, Latham, Nova, Prelude Algonquin, Nova Latham, Madawaska, Chief, Newburgh Killarney, Latham, Nova, Reveille, Boyne, Canby, Haida Balder, Asker, Malling Leo, Lloyd George, Nootka Balder, Vene Balder, Veten Asker, Chief, Indian Summer, Muskoka, Ottawa Heisa (nectar raspberry) Ville, Muskoka, Ottawa Ville, Ottawa, Muskoka, Boyne Jenkka Jenkka Ottawa, Muskoka Veten, Latham, Canby Norna, Canby Beskid, Norna Samodiva, Shopska Alena

Hardy cultivars

Nestby 1989 Nestby 1992 Sa¨ko¨ and Hiirsalmi 1980

North America Norway Norway Norway Finland Finland Finland Finland Finland Finland Finland Poland Poland Poland Bulgaria

Meeker, Willamette, Newburgh, Nootka

Glen Clova, Glen Isla, Gradina, Malling Joy, Sirius, Spica Chilcotin, Glen Isla, Orion Meeker, Glen Moy, Skeena, Glen Prosen, Malling Joy Cuthbert, Lloyd George, Malling Jewel, Veten

Heija Haida, Festival, Glen Clova, Glen Isla Glen Isla, Glen Clova

Muskoka, Jatsi, Ville Ottawa, Muskoka, Jatsi Maurin Makea Malling Promise Newburgh, Malling Admiral, Malling Jewel

Bulgarski Rubin, Ihtimanska

Redalen 1986

USA Northern regions

Lauren

Hiirsalmi 1985 Hiirsalmi 1989 Dalman 1991 as reported in Palonen and Buszard 1997 Linna et al. 1993 Dalman et al. 1997 Palonen and Linde´n 1999 ´ raly 1978 Z Wieniarska et al. 1982 Danek and Pasiut 1991 Boitcheva and Lazarov 2004

Galletta and Himelrick 1990

Robbins 2005 Ourecky 1975a

Hanson et al. 2005

USA

Tulameen, Malahat, Lauren

Van Adrichem 1970 Buszard 1986 Zatylny et al. 1996 Bors 2006

References

Canada Canada Canada Canada

Location of test

Viking, Comet Latham, Newburgh Chilcotin, Comox Boyne

Less hardy cultivars

Table 7. Cultivars considered hardy in field experiments.

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temperature was required to injure stem tissue than bud tissue. There were some unusual results with individual raspberry cultivars. For example, the lack of bud hardiness of ‘Chief’, ‘Newburgh’, and ‘Haida’ does not reflect their known hardiness. It may be that these cultivars require a different acclimation regime to achieve maximum hardiness. In a previous study using similar techniques, Warmund and George (1990) found similar discrepancies between laboratory freezing tests and field ratings. Their controlled freezing tests indicated that ‘Canby’ and ‘Chilliwack’ were hardier than ‘Festival’, ‘Nordic’, and ‘Latham’— opposite results to field experience. Warmund and George (1990) suggested that this discrepancy may be due to the fact that (1) field observations do not differentiate between cane and bud injury; (2) some genotypes have secondary buds, which may produce a significant crop if the primary buds are injured; or (3) the laboratory freezing protocol. Zatylny et al. (1996) also reported a poor correlation between freezing tests and field hardiness measurements. The cultivars listed as hardy in Table 7 indicate that few ultra-hardy cultivars have been released since the reviews of Jennings (1988, pp. 26–27) and Daubeny (1996, pp. 139–140). ‘Boyne’ and ‘Killarney’ are still leading hardy varieties in the colder raspberry-growing regions of North America along with the slightly less hardy ‘Nova’, which is from ‘Southland’  ‘Boyne’. In Finland, the standard cultivars are ‘Ottawa’ and ‘Muskoka’, introduced in 1950, although the more recent ‘Jenkka’ has improved hardiness (Dalman et al. 1997). ‘Jenkka’ originates from (‘Malling Promise’  ‘Merva’)  ‘Ottawa’. ‘Merva’ has R. arcticus L. in its pedigree. Although improved in hardiness, the fruit size and quality of ‘Jenkka’ is not significantly improved over ‘Muskoka’. The challenge for breeders is to improve fruit size, firmness, and flavor along with winter hardiness. Jennings (1988) has described 20th-century successes with using species in enhancing cold-hardiness. Both R. idaeus and R. strigosus have been major contributors of hardiness. Tolerance of low temperatures has been noted more recently in R. idaeus in Russia near St. Petersburg (Ryabova 2007). Undoubtedly, many Rubus species are a source of hardiness (Table 8), although whether this approach holds any benefit over breeding with known hardy cultivars is debatable. Van Adrichem (1972) evaluated numerous populations of R. strigosus from Canada and concluded that they ‘‘would be of little value in increasing the winter-hardiness of certain cultivars already available.’’ Similarly in Norway, Nestby (1992) found that eight R. idaeus selections were not more freeze tolerant than the adapted cultivars ‘Balder’ and ‘Veten’. Notwithstanding these reports, useful R. idaeus accessions may yet be identified and readily combined with

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Table 8. Rubus species with potential for use in breeding more cold-hardy raspberries. Hardy species

Origin

R. deliciosus Torr. R. hirsutus Thumb.z

Colorado, USA SE China

R. idaeus L.

Norway Finland

R. innominatus S. Moorez R. leucodermis Doug. R. occidentalis L.z R. sachalinensis H. Lev.z R. strigosus z

Location of test

References

Maryland, USA North Carolina, USA Norway Finland

Finn et al. 2001a Finn et al. 2001a

Leningrad region Russia SE, SW China North Carolina, USA Wyoming, USA Oregon North Carolina, North Carolina, USA USA Maryland, USA Canada Canada

Nestby 1992 Sa¨ko¨ and Hiirsalmi 1980 Ryabova 2007 Finn et al. 2001a Hummer et al. 1995 Finn et al. 2001a Finn et al. 2001a Van Adrichem 1972

Resistant to variable winter temperatures.

cultivars. Furthermore, wider crosses incorporating genes from species other than R. idaeus may provide benefits, especially adaptation to regions with fluctuating winter temperatures. This may become critical if significant climate warming occurs and increases temperature variability. Screening for Hardiness. Thomashow (2001), taking a broad look across species of plants, considered freezing tolerance to be a multigenic trait. This is true for Rubus, as illustrated by Nestby (1992), who found a broad sense heritability of 0.27 for freeze resistance among 16 families. Nestby considered it advisable to screen for freeze resistance in midwinter, late winter, and early spring. Where cold-hardiness is a primary breeding objective, it would be useful to eliminate nonhardy seedlings before planting in the field. This may improve the efficiency of the breeding program, especially since winters are variable in their effect on plants and ‘‘test’’ winters might be rare. A seedling test could incorporate several of the important factors listed by Daubeny (1996). The efficacy of such a test would depend on whether seedlings (e.g., 30–40 cm tall) respond the same as adult plants. This is not the case for Rhododendron seedlings, which gain considerable hardiness as they age from 2 to 5 years (Arora 2002). With Malus seedlings, however, evaluating for hardiness has shown considerable promise (Mathers and Stushnoff 2005).

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A hypothetical screening protocol for raspberries might look like this: 1. Germinate seeds and grow seedlings under long days until 30 cm tall. 2. Grow under short days and cooler temperatures for 1 month to initiate endodormancy. 3. When lower leaves begin to abscise, acclimate with cold temperatures as per Palonen and Linde´n (1999). 4. Apply cold ( 25 C) test temperature. 5. Hold plant at 3 C for 8 weeks to complete endodormancy. 6. Deharden at 10 C for 3 days then reharden for 1 day each at 3 C, 5 C, and 10 C. 7. Apply cold ( 25 C) test temperature. 8. Grow until bud break and select the hardiest for planting the field. It is likely that roots would have to be protected from the full test temperature. This protocol would need considerable experimentation to fine-tune the times and temperatures but could become routine if greenhouse space and a large freezing chamber were available. Without exception, the hardy cultivars that we have today were selected in field plots exposed to the ambient environment of their region. For example, ‘SK Red Bounty’ and ‘SK Red Mammoth’ were selected from seedling populations that were set out with growers in Saskatchewan, Canada. These seedlings were grown for several years before the breeder made his decision (B. Bors, pers. comm.). The minimum winter temperatures of the region would commonly be lower than 30 C and occasionally lower than 40 C. If the breeder is located in a milder climate but seeks to provide cultivars adapted to colder regions, the approach of testing selections at a colder site and then generating seedling populations to grow out and select from at that colder site has merit. Molecular Basis of Cold-Hardiness. There have been considerable advances in the last decade in understanding the cold tolerance at the molecular level, which may lead to producing hardier versions of current cultivars. Much of this gene discovery research has been with Arabidopsis. Yuwansiri et al. (2002) categorized the types of genes that have been the subject of cold tolerance engineering as regulatory genes, cold-regulated (COR) genes, antifreeze protein genes, oxidative stress genes, lipid-modifying genes, and osmoprotectant synthesis genes. The osmoprotectants may be of particular utility in raspberries, considering the relationship between low water content and late-winter bud

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hardiness (Keina¨nen et al. 2006). Resistance to ice nucleation in flower primordia may be related to low water and osmotic potential (Quamme and Gusta 1987). In strawberry leaves, for example, an increase in concentration of the osmoprotectant glycine betaine has enhanced cold tolerance (Rajashekar et al. 1999). Molecular markers, such as quantitative trait loci (QTLs), may be difficult to apply to such a complex trait as raspberry hardiness. However, if raspberry families can be identified that clearly segregate for a crucial aspect of winter-hardiness, such as the ability to reharden in late winter, then the approach holds promise. In particular, unique simple sequence repeat marker pairs have been identified in Rubus (Stafne et al. 2005). Some of these may be linked to hardiness. A recent effort to study gene expression at the time of endodormancy release has identified numerous expressed sequence tags related to dormancy and possibly hardiness (Mazzitelli et al. 2007). Screening seedling populations with these markers should be attempted to see if significant hardiness gains can be realized. 2. Cool Conditions. In general, raspberries are well adapted to cool conditions, and with many cultivars, the optimum growing temperatures are between 14 and 20 C. Photosynthesis and growth is often reduced as temperatures increase above 20 C. Adaptation to warmer conditions has commonly been sought from Asiatic raspberry species, as it is widely lacking in R. idaeus and R. strigosus. However, cool conditions may have a significant effect on the growth and productivity of some cultivars through interference with fruit set during flowering. This effect is also shown in blackberries when cultivars selected in hot conditions have been moved to a new, cooler environment. The blackberry cultivar ‘Ebano’, selected under high temperatures in Brazil, is an extreme example of this, showing very poor fruit set, misshapen fruit and uneven ripening when grown under the cool temperatures of New Zealand (H.K. Hall, pers. observ.) To a lesser extent this is also observed also in ‘Navaho’ blackberry, selected in the heat of Clarkesville, Arkansas. These cultivars also set regular fruit when grown in a greenhouse. Poor set under cool conditions has been a major factor when raspberry cultivars have been selected in a warm environment and then taken to cooler locations around the world. Many selections and cultivars from the Pacific Northwest in North America taken to Scotland have exhibited this failing, and most have not shown much outdoor fruiting potential in the new environment (D.L. Jennings, pers. comm.). However, ‘Meeker’ was able to handle the environmental shift

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to Scotland, and it has been used effectively in breeding new cultivars by SCRI. In New Zealand, ‘Marcy’ raspberry sets fruit well in the Nelson climate, but it shows markedly reduced fruit set in cooler Canterbury conditions, where even RBDV-free clones show crumbly fruit and numerous aborted drupelets. When the same plants are grown in a greenhouse with elevated temperatures, fruit set is regular and normal. This weakness is handed on to progenies and showed up in ‘Motueka’, which has ‘Marcy’ as one grandparent, and displayed reduced fruit set and crumbliness when trialed in Washington State, and reduced pollen production and viability in British Columbia (Kempler, pers. comm.). In contrast, selections and cultivars from SCRI and EMR have been very useful for breeding in the United States and Canada, without any issues of poor fruit set. When crosses are done within cool-sensitive and insensitive cultivars of raspberry or blackberry, progenies segregate for this trait. It is relatively easy to select for insensitive types as long as the selection environment puts pressure on the seedlings for this trait. 3. Low-Chill Climates and Hot Conditions. Resistance to leaf and cane disease has been a key to adaptation, plant health, and survival in hotter, more humid climates (Brooks and Olmo 1944; Darrow 1935, 1937, 1967; Drain 1939; Poling 1996; Stanard 2006; Stafne et al. 2000). Resistance to leaf and cane disease has been obtained through the use of species from tropical Asia, which photosynthesize normally at higher temperatures (Stafne 2000; Stafne et al. 2000). Under these conditions, cool-climate cultivars from R. idaeus or R. strigosus origin exhibit a reduction in photosynthesis and gas exchange. Warmtemperate and/or subtropical species from Asia have been used to develop cultivars for the southern and southeastern United States. These include ‘Van Fleet’ (R. kuntzeanus  ‘Cuthbert’ 1924), ‘Dixie’ (R. biflorus  ‘Latham’ 1938), ‘Dorsett’ (‘Van Fleet’ R. parvifolius 1940s), ‘Mandarin’ (R. parvifolius  ‘Taylor’ 1955), ‘Citadel’ (‘Mandarin’  Md S420-5 [‘Sunrise’  < ‘Newburgh’  ‘Lloyd George’> ] 1966), ‘Fallgold’ (NH 56-1 [‘Taylor’  R. pungens Oldhami]  [‘Taylor’  R. pungens Oldhami] 1967), ‘Southland’ (NC237 [JH8 R. parvifoliusUS9< ‘Latham’  ‘Ranere’>  ‘Newburgh’]  Md S420-5 1968), ‘Dormanred’ (R. parvifolius  ‘Dorsett’ 1972) and ‘Prestige’ ([‘Taylor’  R. pungens Oldhami]  S2 1979). These cultivars have addressed several issues that limit the growth and production of red raspberries in the southern and southeastern states of the United States (Swartz et al. 1992), but fruit quality of these cultivars has now been surpassed by more modern cultivars developed in temperate zones. Adaptation is available for tropical locations like Puerto Rico, but

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developments using species and cultivars that are suited to these conditions have not been pursued for many years and no new cultivars have been developed since the Queensland raspberry, R. probus, a hybrid of R. rosifolius and R. ellipticus (Griffith 1925). Adaptation to high-temperature conditions is important and drought resistance is essential in these conditions, especially where gas exchange is reduced and water losses are high (Stafne et al. 1999). Another effect of high temperatures, high light, and/or exposure to high UV light conditions, even at lower humidities, is damage to developing and ripe fruit (McGregor 1993). Exposed fruit may show sunburn with drupelets turning white rather than coloring up red as with normal development (Renquist et al. 1987, 1989). In very-high-temperature conditions, fruit may develop scald, with drupelets or whole fruit turning a dull red color and becoming very soft, even inside the bush where not exposed to direct sunlight (H.K. Hall, pers. observ.). Effects of high temperature and high light can be ameliorated by cloud cover or atmospheric smoke as well as use of plastic tunnels, shading, or fans (H.K. Hall, pers. observ.; Renquist et al. 1987). Breeding in Australia has resulted in a number of selections that have significantly improved heat tolerance and resistance to both sunburn and scald (H.K. Hall, pers. observ.). 4. Greenhouses and Tunnels. Production under glass or plastic has become very important for fresh raspberry production in many parts of the world, protecting the fruit from rainfall and from other environmental challenges, even snow in some locations. Many diseases and pests are significantly limited by the indoor environment, especially when humidity is not too high and temperature variation is not enough to bring the atmosphere to dew point. Under these conditions Botrytis is greatly reduced as are other fruit rots and cane diseases. In modern greenhouse construction, it is also possible to exclude insect pests through the use of insect-proof screens on vents and cooling pads. One pest of particular importance under plastic and glass is twospotted spider mite (Tetranychus urticae Koch.), especially in a warm temperate climate. Two-spotted spider mite resistance is of particular value under these conditions. Considerable variation in susceptibility exists among raspberry germplasm so that some plants carry high populations of this pest and are heavily webbed and covered with mites, while others are almost free of infestation. Powdery mildew fungus (Sphaerotheca macularis) can also be problematic in production under glass or plastic, especially when humidity rises. These conditions can occur under low-light environments often experienced during off-season production. Some cultivars

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that show no significant infection in outdoor production may be highly susceptible under cover. Relatively few cultivars have been tested under these conditions, and relative susceptibility is unknown (D. L. Jennings, pers. comm.; C. Weber, pers. observ.). The under-cover environment is more benign than outdoors at the same location. However, seven factors need to be considered when selecting a cultivar for growing under these conditions: 1. The indoor environment is warmer than outdoors and plants gain significantly less chill than outdoors at the same location if kept in those conditions year round. 2. Temperatures at flowering time are higher than outdoors. At moderate locations, this will increase fruit set over the same cultivar outdoors, and at very warm locations, high temperatures will reduce fruit set compared to outdoors. 3. Indoor conditions are significantly different from outdoors, and selection of new cultivars ideally should be done in the same environment. 4. Fruit set will generally be better than outdoors, especially in cool locations, making it possible to grow cultivars not at all adapted to outdoor conditions at that location. 5. Selection in this environment may lead to choice of clones well adapted to those conditions but less adapted to conditions in propagation fields, where pests and diseases may arise that do not show under tunnels or glass. 6. Selection for genetic spinelessness will be valuable for cultivars grown under these conditions, making it possible to keep rows closer together without scratching pickers. 7. Fruiting laterals should be short and productive to enable close spacing in these conditions. 5. Other Adverse Environmental Conditions. Raspberry cultivars often show considerable damage from exposure to high wind conditions, and continuous daily wind exposure significantly limits plant growth. Commercially this is addressed by erection of shelter belts or windbreaks, limiting damage from high winds and eliminating growth restriction from daily wind patterns during the growing season. However, eliminating air movement also increases likelihood of damage from frost and increases fruit rot during the harvest season. No efforts have been made to select raspberries for resistance to damage from strong winds or to the effects of diurnal winds, but variation in germplasm offers scope for selecting for adaptation to windy conditions.

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The majority of raspberry cultivars have been developed largely from R. idaeus and R. strigosus, and they are well adapted to deep, welldrained soils. Nevertheless, recent cultivars almost all contain genetic contributions from R. occidentalis and in some cases up to four additional species. These have in many cases given extended adaptation to new environments and poorer soil types. In most raspberry production regions around the world, the best soil types are limited. Pressure to increase production has led to attempts to produce a crop on heavier, less well-drained soils. Adaptation to these conditions varies among raspberries with some cultivars showing considerable sensitivity to heavier soils or to the presence of water lying in the planting for any longer than a minimal period. Modern management and production methods can exacerbate soil problems with the use of tractors, other heavy machinery, and the practice of clear cultivation, causing breakdown of soil structure and the formation of compaction pans in the soil profile. Loss of organic matter and the use of spray chemicals that kill resident populations of earthworms also cause significant degradation of soil conditions and limit the productive growth of raspberry plantations. These issues are often compounded by disease, especially Phytophthora root rots, which are adapted to anaerobic conditions with significant liquid water around the roots of the raspberries. Problems with drainage can be reduced by use of deep cultivation, ridging, growing of cover crops, use of soil modifying agents, addition of organic matter, and the use of a no-cultivation regime with a grassed swathe between rows. However, there are a number of species of raspberries and accessions of R. strigosus that have resistance to waterlogging and to Phytophthora root rots (Kempler and Daubeny 2008). These have been and are being used in breeding to develop new cultivars that can withstand disease pressure and poor soil conditions. Particular progress is being made in the breeding programs in Washington State (WSU), British Columbia (PARC-BC), Scotland (SCRI), Norway, and New York State (Cornell University, Geneva). B. Diseases and Pests Raspberry is a high-value crop with a long establishment period that incurs high capital costs. To protect this investment and assure highquality fruit production, historically most growers have relied on the use of insecticides to manage pests (Gordon et al. 2002). As a minor crop worldwide, raspberries do not have consideration by agrochemical companies developing new active ingredients and formulations because

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the market is too small. Only when chemicals for major crops have a proven track record will companies begin to consider their use on minor crops, but because the cost of registration of new chemicals is high, even effective chemicals often do not become formally approved for use. In addition, older chemicals are under continuous review, and many have been withdrawn for commercial reasons or on toxicological grounds. With fewer chemicals available for use, decisions about how best to protect minor crops are increasingly difficult to make. (Williamson 2003). Supermarket and consumer demands to lower pesticide residues have led to the introduction of maximum residue levels (MRLs) to protect the consumer and the environment from excessive application of chemicals. This has had a major impact on the approaches made by retail outlets toward fruit producers. The multiple retailers may dictate which cultivars to be grown for their outlet with little regard for the relative pathogen susceptibility of that cultivar, resulting in cultivar choice based primarily on fruit size and appearance rather than pest and disease tolerance. While the concept of ‘‘traceability to source’’ for each fruit consignment offered for sale now should ensure that consumers are protected from excessive spray applications, it does present challenges to the grower for producing the perfect product required retailers and consumers. The increase of protected cropping systems in the United Kingdom has caused a shift in pest and disease pressures. While covering the crop can reduce some fungal diseases, such as gray mold (Botrytis cinerea), spur blight (Didymella applanata), and cane spot (Elsinoe veneta), it has increased the importance of raspberry yellow rust (Phragmidium rubiidaei) and powdery mildew (Sphaerotheca macularis) due to increased temperature, relative humidity, and inadequate ventilation (Williamson 2003). Pest species are also affected by this change in the cropping environment. Two-spotted spider mite (Tetranychus urticae) is now a pest under tunnels in Scotland and other growing regions and requires biological control during the picking season. Virus levels are also predicted to increase since populations of aphids are present on the crop for extended periods beyond the traditional growing season. Integrated pest management (IPM) is a control strategy to reduce the use of chemical inputs by using complementary methods such as cultural practices, crop monitoring, natural and introduced predators, resistant cultivars, and strategic use of chemicals. In the 1990s in Europe, the ‘Reduced Application of Chemicals in European Raspberry (RACER) production project brought together commercial and scientific partners from seven European countries with the goal of developing suitable monitoring and/or forecasting methods to detect a range of

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arthropod pests of raspberry and a standardized system to detect fruit rots. This multicentered approach with specific objectives set by industry can be seen as a blueprint for future research on sustainable raspberry production in Europe by bringing together the experts to tackle problems in the diverse geographical zones in Europe. The RACER project investigated integrated control of raspberry beetle (Byturus tomentosus), two-spot spider mite (Tetranychus urticae), Otiorhynchid weevils, cane midge (Resseliella theobaldi), and a detection system for postharvest fungal rots (Gordon et al. 2002, 2005, 2006). Another project was initiated in Washington State to assist the industry in the adoption of an IPM approach to solving pest problems by knowledge transfer among scientists, agronomists, and growers, since communication within the industry is essential if IPM is to be accepted. This successfully led to increased grower awareness about pest species and a better understanding of crop scouting or monitoring and ultimately to a positive change in grower attitude and practices toward IPM (MacConnell et al. 2002). One cultural practice utilizing IPM strategies is biennial cropping, which provides an opportunity to break the cycle of many pathogens. It is considered to provide a significant level of control of several pests and diseases as well as potentially reducing labor costs and offering adequate returns. Propagation stock has been blamed for the distribution and spread of many pathogens for many years. Planting new areas of raspberry with disease-free propagation stock is essential. The importance of certification schemes has increased, providing propagators and growers with planting material derived from high-health mother stock, limiting the spread of harmful pests and diseases. Ultimately, the source of effective control comes from cultivars with robust resistance. Resistance breeding is crucial for the development of cultivars suitable for production using IPM. C. Resistance to Fungal Diseases The attack of fungal diseases is a key issue that affects the growing and economic production of raspberries in almost all production regions around the world. Fungal diseases attack every plant part: root, canes, leaves, and fruit. Among these are diseases that limit or preclude growth and/or production under environmental conditions that favor the disease. Fungal diseases attacking roots include Phytophthora fragariae var. rubi (Duncan and Cooke 2002; Wilcox et al. 1993), Verticillium dahliae, Armillaria root rot and white root rot Vararia sp. (Ellis et al. 1991).

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Fungal diseases attacking canes and leaves of raspberries include anthracnose or cane spot, Elsinoe veneta (Burkholder) Jenk.; cane blight, Leptosphaeria coniothyrium (Fuckel) Sacc. ¼ Coniothyrium fuckelii Sacc.); spur blight, Didymella applanata (Niessl.) Sacc.; cane Botrytis, Botrytis cinerea, pers.; Fusarium wilt, Fusarium avenaceum (Corda ex Fries) Sacc.; ascospora dieback, Clethridium corticola (Fuckel) Shoemaker & E. Mu¨ller; rosette ¼ double blossom, Cercosporella rubi (G. Wint.) Plakidas.; downy mildew, Peronospora sparsa Berk.; powdery mildew, Sphaerotheca macularis (Wallr.: Fr.) Lind.’ raspberry leaf spot, Sphaerulina rubi Demaree & M.S. Wilcox; Sydowiella and Gnomonia cane cankers, Sydowiella depressula (P. Karst.) Barr ¼ Gnomonia depressula P. Karst.; nectria canker, Nectria mammoidea W. Phillips & Plowr. var. rubi (Osterw.); Weese ¼ Cylindrocarpon ianthothele var. ianthothele Wollenw; and silver leaf, Chondrostereum purpureum (Pers.: Fr.) Pouzar ¼ Stereum purpureum, pers.: Fr. (Ellis et al. 1991; Weber and Entrop 2007). Fungal diseases attacking flowers and fruit of raspberries include Botrytis blossom blight and Botrytis fruit rot; gray mold ¼ Botrytis cinerea, pers.: Fr.; postharvest soft rot caused by Rhizopus and Mucor species; minor fruit rots including Alternaria spp., Cladorsporium spp., Penicillium spp., and Colletotrichum gloeosporoides (Penz) Penz. & Sacc. In Penz.; and stamen blight, Haplosphaeria deformans (Syd.) Syd. (Ellis et al. 1991). Rust diseases on raspberries include orange rust, Arthuriomyces peckianus (E. Howe) Cummins & Y. Hirasuka, the long-cycled form and Gymnoconia nitens (Schwein.) F. Kern & H.W. Thurston, the short-cycled form, which only affects blackberries and black raspberries with red raspberries being immune; cane and leaf rust, Kuehneola uredinis (Link) Arth., which is rare on red and black raspberries; yellow rust, Phragmidium rubi-idaei (DC.) P. Karst; and late leaf rust, Pucciniastrum americanum (Farl.) Arth. Minor rust diseases are also reported in the Arctic: Pucciniastrum arcticum Tranzschel, which affects R. arcticus; R. saxatalis L., R. pubescens Raf., and R. triflorus Richardson and Phragmidium arcticum Lagerh. on R. arcticus and related fruits. Minor rusts in the subtropics include Hamaspora longissima (Thu¨m.) Ko¨rn., which has not been reported to attack raspberries (Ellis et al. 1991). D. Fungal Diseases Attacking Roots 1. Phytophthora Root Rot. Phytophthora fragariae var. rubi is a devastating disease of red raspberry in nearly all temperate growing

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Fig. 24. A raspberry field with an area of severe infection of Phytophthora fragariae var. rubi resulting in plant death. (photo by SCRI).

regions of the world, and it significantly limits production capacity in the absence of control (Fig. 24). Affected plants usually are found grouped in areas with saturated soil. These are generated in areas where runoff collects, excessive irrigation or rainfall has ponded, or simply where soil is compacted, is heavy, or where water does not drain off or move through the soil profile. Often disease will appear in low-lying areas and spread through water uphill from the infected site when liquid water is available. When water drains off an infected field and comes into contact with other plantings, then disease spread is also via liquid water from field to field. All parts of the plant below or at ground level can become infected, including roots, root buds before emergence, crowns, and the bases of primocanes or floricanes. Typical disease symptoms include reduced frequency of primocane emergence and collapsing floricanes. Foliar symptoms include chlorosis, interveinal and perimeter necrosis, and scorching. In the advanced disease stages, the pathogen destroys most or all of the root system and colonizes the crown and lower stem region, producing a characteristic water-soaked lesion that advances acropetally (Wilcox 1989). Diseased stools yield little or no fruit and often die. With large areas affected, producers can suffer considerable financial loss (Duncan and Cooke 2002). Once introduced, the pathogen can remain in the soil for several years in the absence of a host (Heiberg 1999). Several different species of Phytophthora were isolated from infected plants when the disease was first found, and naming of the species

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isolated varied from place to place (Duncan et al. 1987; Duncan and Kennedy 1989; Ellis et al. 1991; Washington 1988;). However, in the early 1990s, the predominant species infecting raspberry plantations in numerous sites around the world was recognized to be Phytophthora fragariae var. rubi (Pfr) (Duncan and Cooke 2002; Wilcox and Latorre 2002; Wilcox et al. 1993). While a number of different species of Phytophthora have been observed in raspberries around the world, isolates of Pfr are the most virulent and do the most damage to raspberries. Problems with root rot in raspberries leapt to international significance in the 1980s when serious outbreaks were documented on red raspberry in central and eastern North America, the United Kingdom, and continental Europe (Ellis et al. 1991; Gordon et al. 2005; Lovelidge 1989). Since the 1980s, raspberry root rot has spread rapidly to affect most northern European countries, the Americas, and as far as Australia in 1994 (McGregor and Franz 2002). Recognition and characterization of the disease, as well as improved detection techniques, showed the widespread importance of Pfr at that time. It was suggested that one cause of the rapid spread was through the propagation chain and distribution of infected planting stock by the nursery industry (Duncan and Cooke 2002; Wilcox and Latorre 2002). This was compounded by the advent of virulent isolates and through periods of weather especially favorable for the disease. Spread of Pfr to some locations also may have been on machinery used in the fields or even on the shoes of visitors to a plantation, especially during wet conditions. Spread of Pfr within a field and through sales of plants has also been accelerated through widespread use of susceptible cultivars; for example, the highly susceptible cultivars ‘Glen Moy’ and ‘Veten’ were widely planted in the 1980s in Scotland and Norway respectively. The known magnitude of Pfr spread also has been extended through the improved ability of pathologists to detect and characterize the disease. Growers have been encouraged to adopt integrated control methods in an attempt to limit the spread of the disease, including:  Planting on raised beds, or ridges, to improve drainage and aeration and in some soils improves plant growth and fruit yields (Heiberg 1995; Maloney et al. 1993). This is becoming standard practice worldwide (McGregor and Franz 2002).  Gypsum application also improves soil structure and assists raspberries to overcome Phytophthora infection (Gordon et al. 2005).  Infected plantings may be given a new lease of life or spread of infection may be slowed by deep ripping and through drainage

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works getting rid of excessive water in the field (Harrison et al. 1999b; Lovelidge 1996; Maloney et al. 1993; McGregor and Franz 2002).  The use of bedding polythene mulches combined with trickle irrigation systems to control soil moisture during the growing season (Heiberg 1999).  Purchasing of plants derived from high-health, disease-tested stock and to avoid infected sites and those with poor drainage.  Application of the fungicides metalaxyl or oxadixyl, in conjunction with the practices above has been effective in controlling the disease in some areas (Bristow 1980; Heiberg 1995). However, fungicides are expensive and have to be applied at least twice annually. In the United Kingdom, as chemicals are withdrawn, new chemicals have to be tested by the industry since the minor importance of the raspberry crop means that no fungicide would be developed by the agrochemical industry on the basis of its potential to control raspberry root rot. Several studies have been undertaken to develop integrated control of Pfr, but results invariably show that host resistance provides the most effective control (Duncan and Cooke 2002; Heiberg 1995; Maloney et al. 1993; Wilcox et al. 1999;). There is a great need for Pfr-resistant cultivars possessing superior agronomic characteristics. Breeding for resistance to Pfr started in the late 1970s and early 1980s (Barritt et al. 1979a; Lovelidge 1994). Breeding for Pfr resistance was a priority in programs in Australia, Germany, and Oregon until the programs ceased; it continues in the WSU, PARC-BC, Cornell University, SCRI, EMR, and Norwegian programs. Resistance effective against Pfr appears to be effective against most, if not all, other Phytophthora species that affect raspberry. Sources of strong resistance include ‘Latham’, ‘Asker’ (¼’Winkler’s Sa¨mling’), ‘Newburgh’, ‘Durham’, ‘Chief’, some local resistant clones in Scotland, R. strigosus and the species R. coreanus, R. crataegifolius, R. illecebrosus, R. lasiostylus, R. occidentalis, R. odoratus, R. parviflorus, R. parvifolius, R. phoenicolasius, R. pileatus, R. spectabilis, and R. sumatranus (Barritt et al. 1979a, 1981; Bristow et al. 1988; Daubeny 1996; Finn et al. 2002; Heiberg et al. 1999; S.N. Jennings, pers. observ.; Jennings et al. 2008; Knight and Ferna´ndez Ferna´ndez 2008b). Screening and selection of cultivars of red and other raspberries and wild Rubus species began soon after it became apparent that root rot was a major problem. Breeding populations are traditionally screened for Pfr resistance in infested field plots, where progenies are grown up from seed and planted directly into a plot previously infected with the

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disease. Susceptible genotypes are planted alongside as controls, and selections can be made once the controls become infected and die. Field screening has the advantage of mimicking the conditions of commercial production. However, this method can add several years to a breeding program; field infestation can become patchy, and variability in disease development can occur. This has led to glasshouse or pot screening (Pattison et al. 2004). Duncan and Kennedy (1991) developed a method of glasshouse screening for root rot that has been used and modified over the years. In the glasshouse, potted plants typically are grown in soil that has been inoculated with the pathogen and kept in conditions optimum for the growth of the pathogen: excessively wet with frequent irrigation or flooded to provide periods of standing water with temperature 10 to 15 C. Glasshouse screening allows genotypes to be screened quickly versus field screening; however, there have been some problems associated with glasshouse screening. Space and resources are a limiting factor when screening thousands of seedlings in a breeding program. Seasonality is a constraint since the pathogen prefers cool temperatures; therefore, screening cannot be carried out during the summer. Results frequently have been found to be too aggressive, reducing apparent resistance from some genotypes by removing those with intermediate resistance and allowing only the most resistant genotypes to survive (Harrison et al. 1999b; Wilcox et al. 1999). Pattison et al. (2004) described a new method, using a hydroponic system that reduces environmental variability potential with the glasshouse screening method, allows large numbers of seedlings to be screened at one time, and, crucially, identifies intermediate types. In Australia, resistance was obtained from ‘Chilliwack’ and ‘Haida’ derivatives but thus far no new resistant cultivars have been released. In Germany, ‘Autumn Bliss’, ‘Latham’, and ‘Winkler’s Sa¨mling’ were used as sources of resistance. Percentages of resistant progeny from the populations grown averaged 14.2% from the ‘Latham’ and ‘Winkler’s Sa¨mling’ crosses, but only 3.5% of the ‘Autumn Bliss’ seedlings were resistant (Spiegler and Thoss 1993). From these crosses the cultivar ‘Rubaca’ (‘Niniane’) was ultimately released (Daubeny 1997a). In Oregon, the early efforts in breeding raspberries in the 1930s incorporated genes for resistance to root rot by using the resistant cultivars ‘Chief’, ‘Latham’, and ‘Newburgh’ and later root rot resistant selections of R. strigosus from Mt. Mitchell were used for breeding. However, no floricane-fruiting cultivars with the level of Pfr resistance of ‘Cascade Delight’ have been released from the Oregon program over the last 30 years.

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In the WSU program, screening for Pfr resistance has been carried out since the 1970s. Germplasm, seedlings, and selections have been screened in plots at Vancouver, Washington, and at Puyallup and in glasshouse trials with very high root rot pressure (Barritt et al. 1979a, 1981; Bristow et al. 1988). A range of sources of resistance have been evaluated in this program, and the highly resistant cultivars ‘Cascade Delight’ (Plate 2H), ‘Cascade Dawn’, and ‘Cascade Bounty’ have been released within the last five years (P.P. Moore 2004, 2005a, 2006a,b,c, 2007). Sources of resistance for these cultivars are ‘Latham’ via ‘Chief’ or ‘Sumner’ and ‘Chilliwack’, ‘Cuthbert’ via ‘Meeker’ or ‘Sumner’, and ‘Chilliwack’, ‘Newburgh’ via ‘Malling Promise’, ‘Haida’, and WSU 608. New cultivars released from the Norwegian program using ‘Asker’ as a source of resistance are ‘Hitra’, ‘Stiora’, and ‘Tambar’, each showing some field resistance. ‘Chilliwack’ shows good field tolerance in Norway (Heiberg 1995) and has been used as a parent of ‘Frosta’ (Daubeny 2002a; Roen et al. 2002). More recent cultivars released from the PARC-BC program reported levels of tolerance to root rot and good agronomic traits. ‘Chemainus’ (Plates 5B and D) and ‘Cowichan’ (Plate 5F) have good agronomic traits and are reported to have good field tolerance to root rot (Kempler et al. 2006). In the PARC-BC program, three new sources of resistance from R. strigosus have been identified and incorporated into the breeding program (Kempler and Daubeny 2008). After two generations of crossing with cultivated types, there remained very good resistance to Pfr. In the second backcross to red raspberry there are selections that are highly resistant to Pfr and suitable for commercial introduction. In New York State, the Cornell program continues to screen populations in the fields where Pfr was originally isolated as well using the hydroponic system developed by Pattison et al. (2004). The cultivar ‘Prelude’ shows very good field resistance as well as excellent resistance in hydroponic screening (Plate 3A) (Pattison et al. 2004). The older varieties ‘Heritage’ and ‘Taylor’ show good field resistance and intermediate resistance in artificial screening. Sources of resistance in the program include ‘Latham’ and ‘Chief’ and accessions of R. occidentalis and R. strigosus. At EMR, breeding for resistance to Pfr showed that ‘Autumn Bliss’, ‘Grushovka Leningradskaya’, and ‘Valentina’ were highly resistant, as well as the ‘Latham’ control plants. ‘Meeker’, ‘Chief’, and ‘Rubaca’ had moderate resistance (Knight and Ferna´ndez Ferna´ndez 2008b). Five resistant species, R. crataegifolius, R. lasiostylus, R. odoratus, R. spectabalis, and R. strigosus, also were used for breeding, but only one of the selections from progenies showed resistance and other

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selections showed intermediate resistance, moderate susceptibility, or susceptibility. Molecular research at the Scottish Crop Research Institute developed a PCR-based diagnostic to detect Phytophthora species. The test was developed principally for detecting red stele (Phytophthora fragariae var. fragariae) in strawberry. With this detection method, it is possible to detect infection in propagation stocks and help eliminate new root rot outbreaks on land that has never before grown raspberries (Duncan and Cooke 2002; Gordon et al. 2005). The use of molecular techniques in breeding for root rot resistance is examined in more detail in the Molecular Techniques section (Section 111.J, page 126). 2. Other Phytophthora Species. Although P. fragariae var. rubi is considered to be the most widespread and virulent causal agent (Wilcox et al. 1999), several other Phytophthora species have been reported to cause significant damage in diverse regions, including: P. citricola in eastern Europe (Ilieva et al. 1995), Chile (Wilcox and Latorre 1995), and the United States (Wilcox 1989); P. citrophthora in Bulgaria (Ilieva et al. 1995) and Chile (Wilcox and Latorre 1995); P. cryptogea in Australia (Washington 1988), Chile (Wilcox and Latorre 1995), and the United States (Wilcox 1989); and P. megasperma in Chile (Wilcox and Latorre 1995) and the United States (Wilcox 1989). In Scotland, P. idaei was detected in 50% of commercial plantations (Cooke and Duncan 2004). A study is under way to determine how pathogenic this species is to raspberry, in particular with respect to new production methods, protected cropping systems, and long cane production. The hybrid ‘Tayberry’ is well known for its resistance, and black raspberry cultivars ‘Bristol’ and ‘Jewel’ (Plate 3E) have shown good resistance to Pfr (Wilcox et al. 1999), but both these cultivars and ‘Latham’ (Plate 3F) suffered root rot when exposed to P. citricola and P. megasperma in a glasshouse screen (Wilcox et al. 1999). 3. Verticillium Wilt. Verticillium wilt is a minor, sporadic disease of red raspberries in Europe, although it is locally severe on black raspberries and some blackberry and hybridberry cultivars in North America (Ellis et al. 1991; Finn 2008; Keep 1989). Plant reaction of raspberries to the fungi Verticillium albo-atrum Reinke and Berthier and V. dahliae Kleb. (Fiola and Swartz 1994) varies from:  No symptoms with resistant cultivars  Slight leaf and/or stem lesion marginal necrosis

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 More extensive necrosis, chlorosis and death of leaves, with some stem lesions or bluing  Extensive marginal necrosis with one-half of the leaves dead, and/ or blue cane or stem lesions  Some or all canes dead Symptoms first appear on new canes in late summer, with the lower leaves of canes turning yellow and dropping prematurely, or they may develop tiger striping through interveinal chlorosis (Keep 1989). The entire plant is stunted and bluish lesions of infected tissue extend up the canes from the ground, matched by a brown discolored sector in the wood beneath (Keep 1989; Zeller 1936). Canes often die over winter. Fruiting laterals on diseased canes usually develop poorly and may die before the fruit ripens (Keep 1989). Verticillium wilt cannot be effectively controlled through chemical or cultural methods on susceptible cultivars. The most effective means for control of this disease is through genetic resistance (Fiola and Swartz 1994). Black raspberries (R. occidentalis) and purple raspberries, the F1 hybrid with red raspberries, are highly susceptible; even when the percentage of black raspberry is lower, the susceptibility to attack by this fungus is increased over clones with only red raspberry ancestry (Fiola and Swartz 1994). Some resistance or tolerance occurs within red raspberries, both R. idaeus and R. strigosus, although reactions may vary with pathogen biotypes and locations (Fiola and Swartz 1994). The fungus enters the roots and hyphae invade and block the xylem vessels. Conidia also move through the plant in the transpiration stream. The fungus returns to the soil in plant debris and can persist for many years in the absence of a known host (Keep 1989). In the 1930s ‘Cuthbert’ was found to be very resistant but ‘Ranere’, ‘Chief’, ‘Herbert’, ‘Red Antwerp’, ‘Latham’, and ‘Lloyd George’ were also found to show considerable infection (Zeller 1936). Other research at that time also suggested that ‘Antwerp’, ‘Cayuga’, ‘Marlboro’, ‘Ohta’, ‘Owasco’, ‘Seneca’, ‘Superlative’, and ‘Syracuse’ were resistant (Darrow 1937). ‘Willamette’ was also reported to be susceptible, as were ‘Viking’ and ‘Cuthbert’ (Keep 1989). Variable response of ‘Cuthbert’ and ‘Latham’ in the eastern and western parts of North America reported by some researchers is thought to be indicative of different races of the fungus (Converse 1966). Few programs in the last 30 years have taken much interest in breeding for resistance to Verticillium wilt, although the resistant purple raspberry ‘Glencoe’ was released from the SCRI program (Daubeny 1994). Seedlings were screened for resistance in the eastern

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United States (Fiola and Swartz 1989, 1994), and advanced selections were routinely screened for susceptibility in a major Californian program in the mid-1980s (H.K. Hall, pers. observ.). This disease remains a sleeping giant in North America and is still a major problem in black and purple raspberries planted on infected soils. In Europe and internationally, there has been considerable use of black raspberries as sources of firm fruit, fruit rot resistance, and resistance to pests including aphids and raspberry bud moth. Black raspberries are in the background of a high percentage of new cultivars in the last 20 years, and this could lead to increased Verticillium wilt susceptibility and new outbreaks with some cultivars planted on infected land (Keep 1989). 4. Other Root Diseases. Other fungi also attack the roots of raspberries, including Armillaria and white root rot, Vararia sp. (Ellis et al. 1991). Armillaria frequently causes cane dieback and wilting, and infected roots often have a whitish to cream-colored mycelia just under the bark. Mycelia are fan-shaped and about as thick as a piece of paper, and they have a characteristic mushroom odor. While not common, attacks in commercial Rubus plantings have been recorded in North America, Europe, Australia, and New Zealand. When present, this disease may cause serious losses. The disease kills infected plants; it cannot be treated and can only be controlled by removing plants surrounding the infected areas. Besides inhabiting the roots of affected plants, it can persist for decades as wood-decaying fungi in tree stumps and other woody debris in the ground. Armillaria spreads locally by extending white rhizomorphs with a black or red skin through the soil. It also can produce clusters of small yellowish brown mushrooms around the base of an infected plant for dispersal of spores (Ellis et al. 1991; Perry et al. 2003). Spores often germinate and grow on dead tree stumps or other wood waste to create another localized infection from that point. Infection of raspberries usually causes plant death and a steadily increasing circle absent of plants in a field. When infestations are severe, losses can be significant. There is no known resistance. An infected site must be treated by cultivation, removal of buried wood fragments, fumigation, and/or leaving the ground fallow before another raspberry crop can be grown. White root rot (Vararia sp.) is a sporadic disease of raspberry that has only been reported from Australia. In some plantings, white root rot has almost completely destroyed entire plantings over 3 to 4 years but in most cases only a few plants were infected and died annually. White root rot causes yellowing, wilting, and dieback of canes, which is most rapid in young plants. Roots and crowns rot and are covered with a

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dense, white mycelial mat (Ellis et al. 1991). No resistance is known, and the usual response to infestation includes removal of plants, cultivation, and allowing the infected area to remain fallow for a period of years until all infected plant material has rotted away. E. Fruit Rots Several fungi cause fruit rot in raspberry, but gray mold (Botrytis cinerea, Pers.: Fr.) is the most serious worldwide for outdoor production of raspberries, especially in areas with humid or rainy climates. Other species causing fruit rots include Cladosporium, Rhizopus, Alternaria, Mucor, Penicillium, and Colletotrichum (Keep 1989). 1. Botrytis Fruit Rot. This disease causes considerable losses in raspberry production worldwide and is the most important factor limiting the sale of fresh fruit to distant markets, rapidly reducing the shelf life of harvested fruit. However, the problem of fruit rots from Botrytis infection for fresh-market production has been significantly reduced by the popular use of plastic tunnels or greenhouses for indoor culture. Other diseases are likely to assume this place of primary importance, as powdery mildew has in the United Kingdom (D.L. Jennings, pers. comm.). Nevertheless, Botrytis fruit rots appear likely to continue to be a significant challenge for outdoor production of raspberries for processing. The fungus can infect fruit in the field before harvest (preharvest rot) (Fig. 25a), particularly after persistent rain during flowering and in warmer climates when there are heavy dews or rainfall at the time of fruit ripening, but in many locations the main concern is the loss of picked fruits after harvest (postharvest rot) (Fig. 25b). The fungus may attack any part of the fruit but commonly affects drupelets in the fruit collar. Symptoms of the rot include the development of a grayish-brown dusty mass of hyphae and conidia, usually on ripe or ripening fruit. Botrytis fruit rot on green fruit is rare as fruit are normally resistant to active growth and sporulation of this fungus until fruit begins to ripen (Ramanathan et al. 1997; Williamson and McNicol 1986). Early studies suggested that the fungus may attack open flowers and form a symptomless infection (Mason and Dennis 1978). Subsequent evaluations, in conjunction with spray trials at the Scottish Crop Research Institute, confirmed these early findings (Dashwood and Fox 1988). This led to the introduction of the commercial spraying practice of four to six fungicide applications per production season used today in Scotland. Further research demonstrated that conidia of B. cinerea germinate in the stigmatic fluid in newly opened flowers, grow through

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Fig. 25. Gray mold of raspberry caused by Botrytis cinerea: (A) Preharvest infection; (B) Postharvest losses. (photos by H.K. Hall).

the styles, and enter the carpel and form a mycelium. The fungus persists in senescing style and the stamen also becomes colonized, providing a further source of infection for ripe fruit (McNicol et al. 1985; Williamson et al. 1987). While postharvest rot is a major problem for the fresh market, preharvest rot assumes greater importance for machine-harvesting plantations and the processing market, where fruit often must reach a more advanced stage of ripening before being able to be harvested (Barritt 1971). This is due to the slow development of the abscission zone not allowing fruit to shake off by machine until more mature than fruit picked by hand. Poor machine design and inefficient training and trellising of canes can also cause some ripe fruit to miss being harvested when the machine passes. Fully ripe fruit remaining behind rapidly

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develop gray mold promoting the spread to other ripening fruit. By the subsequent harvest, fruit is often badly contaminated and requires considerable sorting to remove contamination from the product (Barritt and Torre 1980; Daubeny and Pepin 1981;Knight 1980b; Williamson and McNicol 1986). Plant architecture also influences preharvest rot. Cultivars that are leafy, have drooping laterals and/or clustering of fruit on the lateral show higher incidence of preharvest rot than those with an open bush, upright laterals, and more widely spaced fruit (Daubeny and Pepin 1981; Celetti 2000; Pritts 2000; H.K. Hall, pers. observ.). Raspberries grown in cool moist conditions are sprayed with fungicide routinely for control of gray mold from the flowering period onward to reduce losses to rot during and after harvest. However, production of raspberries under tunnels or outdoors in drier conditions is possible without any use of fungicides. Where fungicides are regularly used, loss of effectiveness through the fungus developing resistance to the active chemical has been a recurring problem (Jorg et al. 2003; Williamson and Jennings 1992; Williamson and McNicol 1986). Resistance, together with increasing demand from consumers, multiple retailers, and processors for a reduction in chemical use is restricting growers’ ability to control Botrytis and other fungal diseases. Growers have been encouraged to use integrated control methods, such as good weed control and thinning canes to maintain airflow in the plantation and reduce humidity; splitting or reduction of nitrogen inputs (Jorg et al. 2003); and removal of fruiting canes immediately after harvest to reduce the inoculum of Botrytis and other diseases (Williamson et al. 1987). Gordon et al. (2005) describes the investigations of microbial antagonists in an attempt to reduce the number of infections and airborne inoculum for the biological control of B. cinerea, with the idea that the microorganism, once applied, multiplies in the canopy to compete with the fungus for surface nutrients. The antagonist Clonostachys rosea (formerly Gliocladium roseum) completely suppressed sporulation of B. cinerea in leaves and stamens that were inoculated with a high density of the pathogen at 12 to 96 hr after the antagonist was applied (Yu and Sutton 1998). Timing of treatments was shown to be important. Another organism, Trichoderma harzianum (formulated as Trichodex) (O’Neill et al. 1996), uses the secretion of endochitinases, glucanases, and amino acid permeases, reducing the likelihood of the pathogen developing resistance. Another antagonist, Ulocladium atrum, competes for nutrients on plant surfaces and shows promise for gray mold control within an integrated control system (Kohl et al. 1998). Many of these biological control agents have potential for gray mold control, but cool spring temperatures in temperate climates may be a limiting factor.

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Early work on differences of fruit rot susceptibility is well reported (Daubeny and Pepin 1976; Daubeny et al. 1974; Jennings and Carmichael 1975b). Several sources of resistance to B. cinerea have been found including ‘Cuthbert’ red raspberry, R. pileatus Focke (Jennings and Williamson 1982), R. occidentalis L. (Jennings and Williamson 1982; Knight 1980a), R. crataegifolius Bunge (Jennings and Williamson 1982), and R. coreanus Mig. (Keep et al. 1977b). Several different types of resistance to Botrytis have been observed. Resistance from ‘Cuthbert’ is innate, being expressed in progenies, regardless of fruit firmness. ‘Carnival’, also descendant from ‘Cuthbert’, shows resistance to stylar infection, reducing infection in stored fruit. Botrytis resistance is also associated with fruit firmness in derivatives of the black raspberry, R. occidentalis. Methods to screen germplasm for reduced susceptibility to postharvest rots or increased shelf life are well established in many breeding programs. Knight (1980a) describes a method that has been adopted or modified by other programs. Ripe fruits of each genotype were picked and individually spaced onto a plastic tray or punnet that was lined with a damp paper towel then covered with polyethylene. The trays were stored at ambient temperature and rots recorded after 48 and 72 hr. Samples were picked and scored at regular intervals during the season. Rot was found to be influenced by factors such as ripeness, moisture content, microclimates around the fruit, and weather conditions, but the method was found to be useful in determining susceptibility to postharvest rot (Knight 1980a; Stephens et al. 2002). The fungus B. cinerea also infects primocanes and causes the disease cane Botrytis. Associations between cane infection and fruit rot have been suggested, but variable results suggest that susceptibility to cane Botrytis is not a reliable guide to fruit rot susceptibility (Daubeny and Pepin 1981; Knight 1980a, 1980b) Jennings and Carmichael (1975b) found firmness and Botrytis fruit rot resistance to be highly correlated, although later studies found exceptions (Daubeny and Pepin 1981). Resistance was correlated with firmness that had been introgressed from R. occidentalis into firm cultivars such as ‘Glen Prosen’ (Barritt and Torre 1980). The raspberry cultivar ‘Cuthbert’ was resistant to fruit Botrytis, and its derivatives ‘Meeker’, ‘Carnival’, ‘Ottawa’, and ‘Matsqui’ have also shown good resistance (Daubeny and Pepin 1975b, 1976). At EMR, ‘Nootka’ and ‘Glen Isla’ were additional cultivars with low susceptibility (Knight 1980a,b) Research in Russia and at EMR also found that R. crataegifolius showed considerable resistance to Botrytis fruit rot (Isaikina and

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Kichina 1988; Keep 1984b). Introgression of this resistance into advanced Russian breeding lines significantly increased longevity of fruit. Botrytis fruit rot resistance is also reported in R. coreanus and R. niveus, two black raspberry species from Asia (Finn et al. 2002). Studies in New Zealand looked at susceptibility of germplasm with varying proportions of Rubus spp. in the background and found that combining genotypes with both R. pileatus and R. occidentalis may be effective when breeding for postharvest rot resistance (Stephens et al. 2002). Some selections from this material were able to withstand considerable Botrytis inoculum pressure with little or no fruit rots. In earlier populations, segregation occurred with some plants showing no rot immediately alongside plants with all fruit completely mummified with gray mold. In primocane-fruiting types, fruit was able to hang on the plant for an extended period before starting to decompose, but throughout this period no Botrytis infection was observed. In Germany, Jorg et al. (2003) found that ‘Meeker’, ‘Glen Ample’, and ‘Himbo Top’ had low susceptibility to fruit rot. ‘Autumn Bliss’, ‘Tulameen’, and ‘Malling Exploit’ were the most susceptible of the cultivars grown. Research at SCRI has found that infestation of raspberries with the raspberry beetle (Byturus tomentosus) exacerbates gray mold damage (Woodford et al. 2002). Larvae hatch from eggs laid in open flowers and feed on the receptacle and drupelets, causing wounds for B. cinerea to infect, demonstrating one of the many difficulties of low-input production. While almost all raspberry breeding programs have increased resistance to Botrytis as a part of the program, nothing has been published about a program specifically targeted at developing Botrytis-free cultivars for a high pressure environment. An effective strategy for developing raspberries highly resistant to fruit Botrytis would be: 1. Assemble a range of cultivated red raspberry cultivars and Botrytis-resistant clones from a range of wild raspberry species. 2. Intercross them with each other. 3. Screen all seedlings for fruit rot resistance. 4. Self-pollinate and intercross the most resistant clones from each resistant interspecific hybrid. 5. Grow an F2 population and screen all seedlings for resistance. 6. Two to four cycles of interbreeding targeting fruit rot resistance will be expected to yield new selections with significantly improved resistance to fruit Botrytis.

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7. Once Botrytis-resistant clones have been developed, breeding and selection for agronomic characters and fruit quality could be pursued with greater vigor.

2. Minor Fruit Rots. The most recent studies on fruit rot generally focus on gray mold, but there are several other pathogens that cause fruit rots in raspberry. Postharvest fruit rot or leak disease is caused by infection of Rhizopus and Mucor spp. Damaged or mature fruit are infected directly, and symptoms usually occur in postharvest samples late in the season. Symptoms may include water soaking but more obvious is the development of white mycelial growth on the fruit surface, which becomes covered with black pinhead sporangia. As it spreads, the infection causes maceration of the fruit, which causes juice to leak into harvest containers. Frequency of Rhizopus infection appears to be related to environmental conditions, especially temperature. Rhizopus was the predominating fruit rot when temperatures equaled or exceeded 21 C. Botrytis dominated when temperatures were at 16 C and when conditions were wet or humid (Barritt and Torre 1980; Keep 1989; Pepin and MacPherson 1980). Two types of resistance to Rhizopus have been reported: intrinsic resistance from ‘Cuthbert’ and resistance associated with fruit firmness (Daubeny et al. 1980). Resistant cultivars include: ‘Matsqui’, ‘Ottawa’, ‘Meeker’, and ‘Nootka’ with intrinsic resistance and ‘Glen Prosen’ with resistance associated with fruit firmness (Daubeny and Pepin 1974b; Daubeny et al. 1980). Other fungi that cause postharvest fruit rot include species of Cladosporium, Alternaria, Penicillium, and Colletotrichum and are generally associated with late season, overripe, or damaged fruit and occur after rainstorms. Cladosporium rot produces an olive-green mold, usually on the inside of the fruit. Blue mold is caused by Penicillium spp. where, during storage, the infection appears as a powdery fungal growth, initially white and then blue-green. Alternaria rot is caused by Alternaria spp., which produces a dark gray mycelium and is most common on black raspberry in the United States. Knight (1980a) found that resistance to Botrytis fruit rot was positively correlated with resistance to Cladosporium and Alternaria rots (i.e., genotypes that were susceptible to Botrytis tended to be susceptible to Cladosporium and Alternaria). Similarly, genotypes with low levels of Botrytis had low total rots. Resistance to Cladosporium and Alternaria was also associated with fruit firmness (Knight 1980b).

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F. Cane and Leaf Diseases 1. Spur Blight. Didymella applanata affects raspberries worldwide but is particularly prevalent in the Pacific Northwest and Europe (Ellis et al. 1991; Jennings 1988). The disease can cause serious yield losses in red raspberry by reducing the number and vigor of fruiting laterals developing from infected nodes (Keep 1989). Infections on mature leaves of young primocanes are initiated at the leaf margin and advance inward toward the midvein. This results in a brown V-shaped lesion with broad yellow margins. Infection spreads from the leaf through the petiole and into the node. Infected leaves are usually shed prematurely, and a dark chestnut brown spreading lesion (or purple on cultivars with a heavy wax bloom) develops on the cane below the node and around the axillary buds (Fig. 26). During the

Fig. 26. Symptoms of spur blight of raspberry on a dormant cane caused by Didymella applanata. (photo by SCRI).

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autumn, the lesions become indistinct as the primocanes senesce but, during the winter, silver-gray lesions appear and tiny black pseudothecia and later pycnidia develop on them. The buds are rarely killed because they are not invaded by the fungus and remain viable, but are retarded in growth compared to those at noninfected nodes. Yield losses result from reduction in number and vigor of fruiting laterals developing from infected nodes and, in some areas, from increased winter injury (Ellis et al. 1991; Williamson and Hargreaves 1981). Spur blight and cane Botrytis, although taxonomically unrelated, occupy the same ecological niche (Gordon et al. 2005; Williamson and Jennings 1986). Both fungi infect nodal areas of young canes after invading senescent leaves, neither pathogen can penetrate the mature polyderm, and both have similar effects on the axillary buds and the emergence of fruiting laterals. In some breeding material, resistance to spur blight is significantly correlated with resistance to cane Botrytis (Jennings 1980; Knight 1980a). Therefore, it is possible that screening for one disease will lead to a correlated response to the other (Jennings and Williamson 1982). Jennings (1983b) suggested there may be a major gene or genes responsible for resistance to both spur blight and cane Botrytis. This resistance mechanism operates against both pathogens (Williamson and Jennings 1986). Cultivars differ widely in resistance to spur blight and cane Botrytis, and morphology has a considerable effect on resistance (Jennings 1982a). Pubescent or hairy canes tend to be less affected, especially if they are also spine free (Jennings 1988). Canes with a dense waxy bloom also appeared less affected (Jennings 1988). Jennings (1962) speculated a possibility for this was that the presence of hairs aided escape from the pathogen by promoting water run-off but later found this not to be the case since genotypes with pubescent canes were also more resistant to mycelial inoculation of wounds (Jennings 1982a). The characteristic of cane pubescence or hairiness is determined by gene H (genotype HH or Hh), the recessive allele of which gives glabrous canes (genotype hh), but gene H is rarely homozygous (HH) because it is linked with a lethal recessive gene (Jennings 1967a). Jennings and Brydon (1989a) concluded that gene H had a considerable influence on resistance to cane diseases, and selections for resistance could be made by selecting pubescent canes. Jennings (1982a), Williamson and Jennings (1986), and Jennings and McGregor (1988) all agree that although gene H could be used as a source of resistance to spur blight and cane Botrytis, it was generally accepted that the gene also confers susceptibility to cane spot (Elsinoe veneta), yellow rust

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(Phragmidium rubi-idaei), and powdery mildew (Sphaerotheca macularis) and is therefore not a desirable resistance in areas where these diseases are more prevalent. However, Graham et al. (2006) used molecular mapping techniques to identify map regions associated with resistance to cane Botrytis, spur blight, cane spot, and yellow rust and to explore the relationship between gene H and resistance to these diseases. The mapping population used in the experiment was an established population of a cross between ‘Glen Moy’  ‘Latham’, initially generated for developing molecular markers for Phytophthora root rot resistance. ‘Glen Moy’ has pubescent canes and is resistant to spur blight and cane Botrytis. ‘Latham’ has glabrous canes and is resistant to cane spot and yellow rust. The progeny segregated for cane morphology and disease resistance, and map locations associated with resistance were identified for all four diseases. The map location for gene H was determined on linkage group 2 and confirmed the association of this gene with resistance to spur blight and cane Botrytis. However, although cane spot was also determined on linkage group 2, there was no significant association was found between gene H and cane spot or yellow rust resistance (determined on linkage group 4), nor was there evidence of any relationship between resistance to rust and resistance to cane spot. Several Rubus species used in breeding are resistant to spur blight. These include: R. coreanus, R. flosculosus, R. mesogaeus, R. occidentalis, R. odoratus, R. phoenicolasius, and R. pileatus (Jennings 1982b,d; Keep et al. 1977b). Generally blackberries and black and purple raspberries are not affected by spur blight. Using mycelial inoculations, Jennings (1983b) showed that resistance to spur blight was highly correlated with resistance to cane Botrytis in progenies derived from resistant red raspberry, R. coreanus and R. pileatus. Screening germplasm for resistance can be done by systematically inoculating canes in the field (Williamson and Jennings 1986) or by scoring the severity of natural infections in winter when lesions are easily identified. In Canada, ‘Haida’ and ‘Carnival’ provided the best resistance (Daubeny and Pepin 1975a). Other cultivars with some resistance include ‘Chief’, ‘Cuthbert’, ‘Latham’, ‘Lloyd George’, ‘Malling Admiral’, ‘Malling Landmark’, ‘Malling Leo’, ‘Marcy’, ‘Marlboro’, ‘Muskoka’, ‘Newman’, ‘Preussen’, ‘Ralitsa’, ‘Southland’, ‘Turner’, ‘Viking’, and ‘Washington’ (Keep 1989). Some cultivars had variable responses at different locations, including ‘Cuthbert’, ‘Latham’, ‘Malling Admiral’, and ‘Newburgh’, probably due to differences in pathogenicity of

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isolates (Keep 1989). Susceptible clones include ‘Glen Clova’, ‘Glen Prosen’, ‘Malling Delight’, ‘Malling Promise’, ‘Rubin’, and ‘Willamette’. 2. Cane Blight. Leptosphaeria coniothyrium occurs in raspberry in close association with wounds showing few external symptoms on primocanes. If the epidermis of infected canes is scraped off to expose the vascular tissues during late autumn, a brown stripe lesion can be seen spreading from the wound. By spring a lesion may extend through multiple internodes on one side of the cane, causing death of axillary buds or wilt of laterals as it spreads. Lesions can girdle vascular tissues during winter, causing cane death. When this occurs in late spring or summer, the entire cane above the infected wound may wilt and die suddenly (Ellis et al. 1991) but, unlike Phytophthora root rot, healthy primocanes emerge from the base of infected plants. A serious cause of wounds leading to outbreaks of this disease is through the use of harvesting machines with spring-loaded catching plates (fishplates), which produce considerable damage of new primocanes (Williamson and Hargreaves 1978). Disease outbreaks are considerably promoted by rainfall during the growing season so that in Scotland the disease is a major problem, but in the Pacific Northwest it is of much lower importance. This disease is also associated with attacks by the raspberry cane midge Resseliella theobaldi, which may inhabit wounds or cause wounds where feeding occurs in splits of the cane bark, causing midge blight (Gordon et al. 2005). Cane midge also provides openings for attack by other cane fungi that form the disease complex of midge blight. Control of cane blight is affected by keeping the bush open, reducing cane wounding from harvesting machines and other equipment, and cane burning to remove the basal leaves and laterals as well as retard the new cane growth (Ellis et al. 1991; Williamson and Ramsay 1985). Protected cropping systems may promote wounding; when covers are removed after cropping, soft growing tissue is exposed to wind and abrasion on the support trellises, creating wounds and infection sites high on the cane. This, in addition to weather conditions, contributed to an outbreak of cane blight in England in 2003, where the disease was previously of little importance (Allen 2003). Plant resistance is found in ‘Latham’ red raspberry (in Europe only), ‘Chief’, ‘Preussen’, ‘Ralitsa’, ‘Rubin’, ‘Van Fleet’, ‘Columbian’ purple raspberry, in R. coreanus and R. pileatus (Ellis et al. 1991; Jennings and Brydon 1989b; Keep 1989). ‘Cuthbert’, ‘Cumberland’, ‘Lloyd George’, ‘Malling Enterprise’, ‘Pyne’s Royal’, ‘Glen Clova’, and ‘Glen Moy’ are particularly susceptible (Keep 1989).

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3. Fusarium Wilt. In 2006 the cultivars ‘Tulameen’ and ‘Glen Ample’ suffered a rapid spread of extensive damage to floricanes from a cane disease in northern Germany (Weber and Entrop 2007). On investigation, this cane disease proved to be a virulent strain of the fungus Fusarium avenaceum, which occupied a similar ecological niche to the cane blight disease, Leptosphaeria coniothyrium. Both of these diseases are also implicated in the insect pest-fungus association known as midge blight, which is considered in the insect pest section (Section V:H2, page 228). Fusarium avenaceum has also been registered by patent in the United States as a biological control agent for control of R. strigosus and R. parviflorus (Shamoun and Oleskevich 1999). This fungus has previously been isolated from raspberries and was reported under the name of raspberry lateral wilt (Jarvis and Hargreaves 1971), but it has not been widely associated with raspberry cane disease in the intervening period. No detailed studies have been made of the susceptibility of host plants to this disease or seeking any resistance from red raspberry cultivars or other Idaeobatus species. Nevertheless, the widespread effects of this disease in northern Germany, and its association with the cane midge points to the need for studies and action to be taken to limit losses associated with this problem. Fusarium wilt also may be responsible for increased susceptibility to winter damage, as the presence of this organism causes ice nucleation activity (Pouleur et al. 1992). In raspberries this can cause increased ice formation in canes and buds and a higher threshold for cold damage in the plant. 4. Anthracnose or Cane Spot. Elsinoe veneta is a serious disease of black raspberry and susceptible cultivars of red raspberry. On young canes, the disease appears in the spring as small, scattered, circular purple spots but later the lesions develop shrunken gray centers with red or purple margins (Fig. 27) (Richardson 1967). If the infestation becomes severe, lesions may coalesce to form large irregular areas that may extend right around the cane, resulting in defoliation, wilting of fruiting laterals, death of fruiting canes, and damage to flowers, making fruit unmarketable (Ellis et al. 1991). In severe cases, buds on infected canes fail to develop fruiting laterals the following season and yields are reduced (Richardson 1967). Fruit are also attacked, causing depressed spots, especially on some cultivars, such as ‘Canby’. Control is relatively easy using broad-spectrum fungicides or by using lime sulfur and/or copper for organic production (Langford 1995; Partridge 1997). Infection is increased through late summer and autumn rains (McGrath 1999). Cane spot was a serious disease in Scotland until the introduction of

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Fig. 27. Anthracnose or cane spot (Elsinoe veneta) symptoms on a raspberry primocane. (photo by SCRI).

broad-spectrum systemic and contact fungicides for control of Botrytis in the early 1970s, at which time it became rare (Munro et al. 1988). Strong resistance or only slight infection has been found in ‘Autumn Bliss’ ‘Bath’s Perfection’, ‘Chief’, ‘Chilcotin’, ‘Cuthbert’, ‘Espe’, ‘Helkal’, ‘Heritage’, ‘Kostinbrodskaya’, ‘Malling Exploit’, ‘Malling Promise’, ‘Marcy’, ‘Meeker’, ‘Newburgh’, ‘Newman’, ‘Nootka’, ‘Ottawa’, ‘Preussen’, ‘Pyne’s Royal’, ‘Radboud’, ‘Ralitsa’, ‘Ranere’, ‘Rannaya Sladkaya’, ‘Siveli’, ‘Southland’, ‘St. Walfried’, ‘Taylor’, ‘Turner’, ‘Tomo’, ‘Van Fleet’, ‘Viking’, and ‘Willamette’ (Ellis et al. 1991; Keep 1989; Kikas et al. 2002) and the species R. biflorus, R. cockburnianus, R. coreanus, R. crataegifolius, R. glaucus, R. strigosus, R. innominatus, R. kuntzeanus, R. lambertianus, R. morifolius, R. niveus, R. odoratus, R. parvifoliu,s and R. tephroides (Keep 1984b, 1989). Susceptible cultivars of red raspberry include ‘Canby’, ‘Fairview’, ‘Glen Clova’, ‘Glen Moy’, ‘Lloyd George’, ‘Malling Jewel’, ‘Malling Leo’, ‘Norfolk Giant’, ‘Skeena’, and ‘Washington’ (Keep 1989).

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Greater susceptibility tends to be associated with gene H, which confers cane pubescence and resistance to spur blight and cane Botrytis (Jennings and McGregor 1988; Williamson and Jennings 1986). This was contradicted by Graham et al. (2006), who confirmed the association between cane Botrytis and spur blight but found no association between gene H and cane spot when using molecular mapping techniques to explore relationships between these diseases. Breeding for cane spot resistance using a diallel of seven cultivars showed strong cane spot resistance in seedlings from crosses between ‘Viking’ (‘Cuthbert’  ‘Marlboro’), ‘Willamette’ (‘Newburgh’  ‘Lloyd George’), and ‘Early Red’ (‘Lloyd George’  ‘Cuthbert’) (Aalders and Craig 1961). 5. Cane Botrytis. This disease is caused by Botrytis cinerea, the same fungus that causes gray mold on fruit. Cane Botrytis has many features in common with spur blight, and the two diseases are often found in the same plantation or on the same canes and are often confused. Like spur blight, cane Botrytis can cause serious yield losses through bud failure, although cane Botrytis is considered to be the more damaging of the two diseases. Cane Botrytis infects mature or senescing leaves of primocanes in a similar way to spur blight, although the subsequent spread can be much more extensive (Fig. 28). The fungus spreads through the petioles to the nodes and forms a tan-colored lesion, which spreads rapidly around the cane. Botrytis lesions often show a characteristic banding pattern or watermark caused by changing growth rates or the fluctuating environmental conditions. The lesions become white during the winter and develop black blisterlike sclerotia that release spores the following spring and are considered the principal initial sources of inoculum for infection of flowers and fruit (Ellis et al. 1991). Lesions of cane Botrytis can be distinguished from spur blight by their lighter tan color and watermarks, when they are present. Lesions of B. cinerea are generally longer than those of D. applanata and often inhibit growth of laterals shoots several nodes from the point of infection or artificial inoculation. As is the case with spur blight, infected tissue causes a delay in bud development and the buds themselves are smaller at the end of the season than uninfected buds, but with B. cinerea, bud dwarfing is more severe and, during the following spring, the smaller buds at infected nodes tend to be suppressed by healthy, fast-growing buds (Gordon et al. 2005; Williamson and Jennings 1986). B. cinerea is a ubiquitous fungus that survives in dead and dying plant tissues of all plants. It can therefore be imported from neighboring

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Fig. 28. Cane Botrytis symptoms showing lighter-colored cane and watermarks. (photo by SCRI).

plantations and crops. The fungus is unusual in that it can be dispersed by dry air, by splash dispersal, and by insect dispersal (Williamson 2003). Current control of cane Botrytis in commercial plantations in Europe is accomplished by spray programs used for control of Botrytis fruit rots. However, growers are encouraged to adopt integrated methods of production to limit inoculum levels, since fungal inoculum increases with plantation age, and to reduce chemical applications, which are becoming increasingly undesirable (Williamson. 2003). These methods, useful for assisting control of many fungal pathogens. include: planting disease-free stock to avoid introduction of pathogens; removal of inoculum and opening the canopy by removing

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old fruiting canes immediately after harvest; adequate ventilation of protected cropping systems; good weed control; moderate nitrogen application; and crop ‘‘scouting’’ to identify early pathogen outbreaks in a plantation. Biennial cropping that involves complete removal of primocane growth in one year and total removal of fruiting canes the following year is effective in breaking life cycles and reducing the impact of persistent pathogens and can reduce production costs (Anthony et al. 1987). Considerable resources have also been invested in research on the use of natural microbial antagonists of Botrytis. Some of these have potential for effective control of the disease. They include Clonostachys rosea, Trichoderma harzianum, and Ulocladium atrum (Gordon et al. 2005). Cane Botrytis resistance is correlated with spur blight resistance, cane pubescence, and gene H. This is discussed in more detail in the section on spur blight (Section V:F2, page 202). Very strong resistance to cane infection with B. cinerea was identified in R. pileatus, R. occidentalis and R. crataegifolius and was transferable to derivatives of crosses between these species and red raspberry to the third generation (Jennings and Williamson 1982; Jennings and Brydon 1989a). The cultivar ‘Chief’ has also proven to be a good parent for resistance, passing on strong resistance for several generations (Jennings 1983a). 6. Raspberry Leaf Spot. Raspberry leaf spot, Sphaerulina rubi Dem. & Wilc., is a seriously damaging pathogen of raspberries in the east and south of the United States, from Maryland to Illinois and Texas to Florida, damaging canes and leaves and resulting in plant death in warmer humid locations, particularly at the southern limits of the raspberry-growing range (Jennings 1988; Keep 1989). It is also found in southeastern Europe and has been a particular problem in warm, lowlying regions in Bulgaria (Tsonkovski and Paneva 1980). Raspberry leaf spot produces inconspicuous lesions on canes and small, tan to brown lesions on the lowest leaves, which spread up the plant (Bost and Hale 2006). Infection of young expanding leaves causes greenish-black spots containing pycnidia. As leaves mature lesions enlarge to 1 to 2 mm, sometimes up to 4 to 6 mm in diameter, become gray or silver, then become whitish and drop out, producing a shothole effect (Ellis et al. 1991). Heavily infected leaves turn yellow, become necrotic, and fall from the plant. By late summer complete defoliation may result, making the plants more liable to winter injury. The fungus overwinters primarily on dead leaves. Most red raspberry cultivars are susceptible to this disease, and it is the key limiting factor for their survival in warmer, more humid regions

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where leaves are shed in late summer and growth is markedly reduced (Drain 1939). An exception to the general susceptibility of red raspberries to leaf spot is ‘Ranere’. This cultivar handed its resistance on to ‘Sunrise’ (‘Latham’  ‘Ranere’), ‘Antietam’ (‘Marcy’  ‘Sunrise’) and ‘Pocahontas’ (‘Hilton’  [‘Taylor’  ‘Ranere’]). In addition, ‘Potomac’ (‘Plum Farmer’ [black raspberry]  ‘Newman’) and ‘Evans’ (black raspberry) were found to be resistant. Further resistance was found in the Asiatic raspberries R. biflorus, R. coreanus, R. microphyllus (R. incisus), R. inorpertus, R. innominatus (R. kuntzeanus), R. mesogaeus, R. morifolius (R. crataegifolius), R. niveus (R albescens), R. parvifolius, R. phoenicolasius, R. rosaefolius, R. veitchii, and R. wrightii (Keep 1989). These species were very useful as a source of resistance in breeding for leaf spot resistance, giving rise to ‘Van Fleet’ (R. innominatus  ‘Cuthbert’) in California, released in 1924, and ‘Dixie’ (R. biflorus  ‘Latham’) from North Carolina in 1938. Breeding using the justmentioned Asiatic species in crosses with red raspberry in North Carolina produced F1 and BC1 selections with high resistance to leafspot (Williams 1950). However, there were considerable numbers of sterile or partially sterile seedlings among these populations. ‘Chief’, ‘Newburgh’, and ‘Taylor’ were better parents than ‘Cuthbert’, ‘Lloyd George’, and ‘Latham’. This is not surprising as the better parents had undergone more generations of breeding improvement. This has also been the experience in New Zealand, with crosses between raspberry cultivars and Asiatic species producing better progenies depending on the degree of improvement of the red raspberry parent. Leaf spot–resistant cultivars released from this program include ‘Mandarin’ ([R. parvifolius  ‘Taylor’]  ‘Newburgh’) in 1945, ‘Citadel’ (‘Mandarin’  Md S420-5 [‘Sunrise’  ‘Oregon 420’ (‘Newburgh’  ‘Lloyd George’)]) in 1966, and ‘Southland’ (NC 237 [JH8 (R. parvifolius  US9 jLatham  Ranerej)  Newburgh]  Md S420-5) in 1968 (Brooks and Olmo 1957, 1968, 1969; J. Ballington and G. Fernandez, pers. comm.). When breeding for leaf spot resistance was carried out in Mississippi, a range of germplasm that was adapted in North Carolina was obtained for use in breeding (Overcash 1972). The cultivar ‘Dorsett’ (‘Van Fleet’  R. parvifolius) was backcrossed to R. parvifolius resulting in the release of the cultivar ‘Dormanred’, which has good heat tolerance and leaf spot resistance (Brooks and Olmo 1972). Modern breeding of cultivars utilizing these resistant sources has not acknowledged whether the cultivars are resistant or not. 7. Powdery Mildew. Sphaerotheca macularis (Fr.) Jacewski ¼ S. humili (DC.) Burr. is widespread on red, purple, and black raspberries around

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the northern hemisphere but is largely or completely absent from the southern hemisphere. In the United Kingdom and North America, it is a minor problem in commercial plantings of raspberries, and on some cultivars it is rarely seen. This is likely because the current cultivars have been selected for resistance, possibly unknowingly, and because of some protection from the use of fungicides for control of other diseases. However, powdery mildew tends to be prevalent in breeders’ plots where there is no chemical control and a full range of resistant through susceptible genotypes can be seen (Keep 1968c). Highly susceptible segregates can be discarded at an early stage. Some cultivars of red raspberry can be affected by powdery mildew under conditions of high humidity and moderate to high temperature. However, this disease is often severe under warm dry conditions, favoring airborne dispersal of the large conidia that infect plants in the absence of water droplets. For this reason, the disease is likely to be more severe in warmer, drier climates or crops produced under protection. Breeding for resistance to this disease for tunnel or greenhouse production of raspberries has become more important with the increase in infestation under these conditions. Selection must be done on populations grown under protection to select the resistance required for these conditions (D.L. Jennings, pers. comm.). Infection of young foliage leads to the development of light green blotches on the upper leaf surface and a white powdery fungal growth matching on the underside. These leaves remain small and tend to curl upward at the margins. Severely infected shoot tips can become long and spindly with the white fungal growth on all leaf surfaces. Flowers and fruit can also become infected. The pathogen survives the winter as mycelium in axillary buds. Cycles of infection of newly expanded leaves occur throughout the growing season as conidia are spread within the crop. Raspberry genotypes that are highly susceptible may suffer severe stunting and yield loss, while infected developing green fruits become unsalable (Ellis et al. 1991). The inheritance of resistance to powdery mildew was reviewed by Keep (1968c), who studied both naturally infected and inoculated plants. The range of resistant material includes wild R. coreanus and R. idaeus, black raspberries, and a range of red raspberry cultivars (Table 5). Most black and purple raspberries are resistant, with the exception of ‘Black Hawk’, ‘Dundee’ and ‘Munger’ black raspberries, and ‘Cardinal’ purple raspberry. Selection for gene H and ss spinelessness for the associated resistances to spur blight and cane Botrytis in the United Kingdom resulted in very high levels of powdery mildew infection (Keep 1989). This resulted in studies being done to assess the inheritance of powdery

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mildew. ‘Lloyd George’, ‘Burnetholm’, and probably ‘Malling Promise’ were heterozygous for three genes that conferred resistance, two dominant and one recessive. Different responses of genotypes screened for resistance suggested that there was no correlation between leaf and fruit infection (Jennings et al. 1969; Keep 1989) and that resistance in the fruit was associated with a shiny skin appearance (Keep 1989). 8. Ascospora Dieback. The ascomycete Clethridium corticola (Fuckel) Shoemaker has resulted in occasional outbreaks of dieback in North America and Europe on both raspberries and blackberries, as well as affecting a wide range of woody hosts and other plants (Ellis et al. 1991). Ascospora dieback appears to require host susceptibility and appears to infect only after low-temperature injury. Ashen-white lesions 7 to 20 cm long appear in late summer or early autumn on primocanes of red raspberries; on black raspberries, they are bluish with a silvery bloom. In early spring or autumn, the lesions become dotted with reddish brown acervuli. After conidia have discharged, the bark surrounding the lesion becomes sooty black. Lesions develop mostly at nodes, suggesting that the infection develops through petioles or leaf scars. Symptoms were reproduced at SCRI by inoculating wounded internodes, but no vascular damage occurred. This disease is at present minor and does not warrant the investment to breed for resistance. 9. Sydowiella and Gnomonia Cane Cankers. Sydowiella depressula or Gnomonia depressula has been found in Scotland on canes of ‘Malling Jewel’ red raspberry growing in temporarily waterlogged soils in winter or in low-lying areas susceptible to frost injury (Ellis et al. 1991; Williamson 1980). Inoculation has not established the pathogenicity of the fungus on red raspberries. In 1979 an outbreak produced a silver coloration of the lower parts of overwintered canes, with numerous black perithecial giving the cane a wartlike appearance. Water-soaked, black-brown vascular lesions circled the canes, killing the vascular tissues and/or the phloem, some wilting before harvest and others ripening the developing fruit. The majority of canes produced laterals only in the uppermost parts. The fungus has also been recorded on R. parvifolius in British Columbia and on dead branches of Rubus spp. in Europe. It does not appear that this disease is of serious risk to commercial raspberry cultivation. 10. Nectria Canker. This disease is caused by the fungus Nectria mammoidea W. Phillips & Plowr. var. rubi (Osterw.) Weese and occurs

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after wind damage, followed by waterlogging (Ellis et al. 1991). This disease is likely a secondary pathogen that comes in after gales, soil compaction, and damage around cane bases. Overwintering canes die before buds sprout or fruiting laterals wilt later in the spring. Primocane production is reduced or absent in some plants, and dark brownpurplish lesions at the crowns cause death of canes and poor primocane growth. Subsequently the plantation returned to full health. This disease is not considered of importance for consideration in breeding new cultivars, but a robust cane attachment to the crown should give some resistance. In New Zealand, a related species, Neonectria discophora var. discophora, also has been reported on raspberry causing similar effects (Gadgil 2005). 11. Silver Leaf. Stereum purpureum (Pers.: Fr.) (syn. Chondrostereum purpureum (Pers.: Fr.) Pouzar) has occasionally been reported to affect raspberries, first being reported in New Zealand in 1939. Other outbreaks have occurred in the United Kingdom and Norway. Disease symptoms include silvering of foliage, poor growth, and death of canes. On dead wood the fungus produces resupinate basidiocarps 2- to 8-cm long, which are white and hairy (tomentose) on the upper surface. The spore-bearing underside of the basidiocarps is smooth and dark purple or brown to violet and fades with age. Silver leaf symptoms on ‘Lloyd George’ were severe. When this cultivar was replaced with ‘Marcy’ (‘Newman’  ‘Lloyd George’), the same disease problems were experienced. Cane death was common, as were gaps in rows and death of individual hills. Wherever ‘Marcy’ was planted in humid or wet climatic conditions, the disease was significant. Other cultivars did not display the same susceptibility, and the disease has not been a problem on new cultivars released in New Zealand (H.K. Hall, pers. observ.; Jenner and Parminter 1980). It appears that silver leaf could be countered by breeding for resistance if it becomes a significant problem in future. 12. Rosette or Double Blossom. Cercosporella rubi (G. Wint.) Plakidas is a severe pathogen of blackberries in southern and eastern states of the United States, where it affects most upright blackberry cultivars derived from ‘Darrow’, ‘Brazos’, and the species R. allegheniensis and R. argutus (Smith and Fox 1991). This fungal disease is a major limitation to the cultivation of blackberries in the southeastern United States (Buckley et al. 1995; Plakidas 1934). In New Zealand, this disease also has become established on ‘Boysenberry’ and other hybridberries, where it has eliminated these fruits from commercial production in

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many parts of the North Island. In these locations, the close proximity of rosette-infected ‘Boysenberry’ has led to infection of raspberries, and considerable debilitation of the plant, making it uneconomic to crop. However, rosette has not become a problem of raspberries in the absence of high infection pressure from nearby blackberries or ‘Boysenberry’ (Ellis et al. 1999; Sauls et al. 1997). Raspberries appear to show more resistance to rosette than hybridberries or upright blackberries and could be considered, along with the semi-upright blackberries, as a source of resistance to this disease (Ellis et al. 1999). Control of rosette in blackberries by the use of fungicides is possible and should be effective if a raspberry block becomes infected. 13. Downy Mildew. Peronospora sparsa Berk. is a pathogen that has increased in importance in Rubus over the last 25 years, becoming a major problem in commercial production of ‘Boysenberry’ in New Zealand, in R. arcticus production in Finland, and also in nursery production of blackberries and hybridberries (Breese et al. 1994; Koponen et al. 2000). Like rosette, downy mildew is uncommon in raspberries, but it has been reported as a problem in raspberry propagation in California (Williamson et al. 1991). In hybridberries, a significant raspberry component in its genetic complement gives increased resistance, as in ‘Loganberry’. Nevertheless, downy mildew is capable of causing significant fruit and leaf damage in raspberries (Williamson et al. 1991). Symptoms of leaf infection in mature leaves of ‘Boysenberry’ are angular lesions, bounded by leaf veins and midribs. In young leaves of tissue-cultured ‘Boysenberry’ or hybridberry seedlings, entire leaves become infected. They quickly are covered with a gray downy mass of sporangia, which can kill a small plant very quickly. In fruit, early infection of ‘Boysenberry’ leads to the condition called dryberry, where fruit are shriveled and dried up, even if they continue to color up and ripen. This symptom is also often accompanied by the splitting of receptacles and drying up to produce a ‘‘trouser-berry’’ effect. When infected at a later stage of maturity, individual drupelets can dry up or shrivel, independently from its neighbors. In raspberry, the ‘‘trouserberry’’ symptom is also found, especially in cultivars like ‘Autumn Britten’ in New Zealand with many berries having split receptacles. Dried and shriveled fruit are also common, as shown in the SCRI annual report for 1990, published in 1991 (Williamson et al. 1991). Effective treatments to limit infection and spread of this fungus include the use of Ridomil, Euparen, Mancozeb, or phosphoric acid.

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When mature ‘Boysenberry’ leaves become infected in the shade, well removed from direct sunlight, they still form angular lesions but there is no pigmentation. This symptom is very similar to that seen in raspberries, often becoming more visible when the leaf is held up to the light. While young seedlings of hybridberries become systemically infected very quickly, raspberries do not appear to become infected in the same way. In spite of the close proximity of infected hybridberry seedlings, seedlings of raspberries have showed no infection (H.K. Hall, pers. observ.). Resistance of raspberries has broken down, allowing downy mildew infection when humidity is very high, especially with the susceptible cultivar ‘Malling Leo’ (Breese et al. 1994; Wallis 1989). Previously thought to be a different Peronospora species, downy mildew of rose has been shown to be able to infect Rubus, and Rubus downy mildew can affect roses (Breese et al. 1994). Thus a disease outbreak in roses produces risk of infection for raspberries cultivated nearby, especially if conditions are cool and wet. If high temperatures and dry conditions are encountered, downy mildew is severely restricted. When power failure resulted in glasshouse ventilation being compromised, a short period of temperatures up to 40 C resulted in eradication of the disease from plants in a glasshouse disease trial (H.K. Hall, pers. observ.). 14. Yellow Rust. Phragmidium rubi-idaei is a relatively minor pathogen of raspberry, except in warm humid climates, where susceptible cultivars may be almost completely defoliated in the autumn. There may also be significant infection on leaves in the springtime as well as infection on the fruits (Jennings 1988; Keep 1989). Anthony et al. (1985b) described the five stages of the life cycle. Only young leaves on laterals and primocanes are affected. The first symptoms are the bright yellow aecia formed on the upper surface of primocane leaves in early spring followed a month later by orangeyellow uredinia on the lower leaf surface in summer. The latter pustules release copious urediniospores that represent the main cyclic phase of infection in raspberries. Toward autumn, the yellow uredinia turn black as teliospores are produced, which is the winter survival stage of the rust. These stick to canes and support trellises before releasing spores the following spring. Premature defoliation can occur if the infection is early and severe, and the consequent reduction in winter-hardiness can result in lost yield. This foliar disease was rarely noted in Scotland before the 1970s, but as new vigorous, high-yielding cultivars, were introduced the disease

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became prevalent, especially in humid and wet seasons on susceptible cultivars such as ‘Glen Clova’, ‘Malling Delight’, and ‘Malling Joy’ (Anthony and Shattock 1983; Anthony et al. 1985a). In Oregon, this disease has long been recognized for its effect on susceptible hosts, especially on ‘Cuthbert’ and ‘Marlboro’ (Zeller and Lund 1933). In this location it has been reported that deeply penetrating rust lesions on young canes predispose them to cane blight infection (Ellis et al. 1991). Two types of resistance are known: strong resistance, conferred by the major gene Yr in ‘Latham’, ‘Chief’, and ‘Boyne’. A second form of incomplete resistance is polygenic and known as the ‘‘slow-rusting’’ type, of which ‘Meeker’ is a good source (Anthony et al. 1986). Rust resistance is also present in ‘Cayuga’, ‘Cumberland’, ‘Fairview’, ‘Herbert’, ‘Lloyd George’, ‘Malling Leo’, ‘Malling Promise’, ‘Marcy’, ‘Motueka’, ‘Moutere’, ‘Newburgh’, ‘Owasco’, ‘Puyallup’, ‘Ranere’, ‘Red Antwerp’, ‘Seneca’, ‘Sumner’, ‘Tadmor’, ‘Tahoma’, ‘Taylor’, and ‘Willamette’ (H.K. Hall, pers. observ.; Keep 1989; Zeller and Lund 1933). In some germplasm, yellow rust resistance was found to be correlated with resistance to cane spot, but Graham et al. (2006) found no association between the two pathogens. 15. Late Leaf Rust. Pucciniastrum americanum (Farl.) Arth. (late autumn rust, late raspberry rust, late yellow rust, or American spruceraspberry rust) is a rust pathogen causing premature defoliation, increasing susceptibility to winter injury, and infecting fruit, making it unfit for fresh-market sales. It occurs in the northern parts of central and eastern North America as well as in California, British Columbia, and Chile, and it was identified in Mexico in 2001. This disease was considered of minor importance, but serious outbreaks in California and on the East Coast of the United States have given the disease greater prominence. Usually it is of minor importance for floricane fruiters, but in one outbreak 70% of fruit was infected in ‘Festival’ in Nova Scotia (Ellis et al. 1991). Primocane-fruiting types are also affected. In one outbreak in Ohio, 30% of the fruit from ‘Heritage’ were rendered unfit for sale. Late leaf rust is not systemic. On mature leaves, small yellow spots develop and turn brown before leaf drop. Small uredinia are formed on the underside of infected leaves, and these shed powdery yellow spores. Badly affected leaves drop prematurely, and canes of highly susceptible cultivars may be denuded by early autumn, also becoming increasingly susceptible to winter injury (Ellis and Erincik 2003). Flowers, calyces, petioles, fruit, and occasionally canes are attacked, and on fruit, uredinia develop on individual drupelets, producing yellow masses of urediniospores, making the berries unfit for fresh-market sales.

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The life cycle of this rust passes through infection on white spruce (Picea glauca), and severe outbreaks on raspberries often occur in association with a high level of infection on spruce earlier in the season. However, outbreaks may also occur on floricane or primocane cultivars far from the alternate host (Ellis et al. 1991). Control of this disease through resistant cultivars is the key to production in areas with high pressure for this disease, especially when the susceptible cultivars ‘Festival’ and ‘Heritage’ are nearby. ‘Carnival’, ‘Caroline’, ‘Jaclyn’, ‘Latham’, ‘Pathfinder’, and ‘Viking’ also are susceptible (Daubeny 2006a; Ellis and Ellett 1981; Elmhirst 2007; Luffman and Buszard 1988). ‘Chilliwack’, ‘Comox’, ‘Esta’, ‘Hollins’, ‘K81-6’, ‘Lawrence’, ‘Malling Joy’, ‘Malling Orion’, ‘Nova’ (‘Southland’ ‘Boyne’), ‘Olympic’, ‘Pocahontas’, ‘Ruby’, ‘Tola’, and ‘Trailblazer’ are highly resistant to late leaf rust in the field, and black raspberries are immune (Ellis and Erincik 2003; Ellis et al. 1991; Fear and Meyer 1999; Jamieson 1989; Jamieson and Nickerson 1999;Luffman 1990; Swartz et al. 2003; Weber 2006; Wilhelm 1991a, 1992). ‘Boyne’ and ‘Royalty’ (NY 253 [‘Cumberland’  ‘Newburgh’]  NY 17861 [‘Newburgh’  ‘Indian Summer’]) also have partial resistance to the rust (Luffman and Buszard 1988, 1989). However, most purple raspberries are susceptible. 16. Orange Rust. Arthuriomyces peckianus (E. Howe) Cummins & Y. Hiratsuka (the long-cycled form) is an important pathogen in black raspberries in northeastern North America, but red raspberry is immune. Gymnoconia nitens (Schwein.) F. Kern & H.W. Thurston (the short-cycled form) predominates on blackberries and dewberries (Ellis et al. 1991). This disease has also been recorded in Europe, Asia, and Australia. Symptoms are visible as growth appears in spring, with young shoots spindly and clustered and new leaves stunted, misshapen, and pale green to yellowish. Spermagonia develop on the upper surface of the leaf even before leaves unfold, and some 3 weeks later the lower leaf surface becomes covered with waxy, blisterlike aecia. As they rupture and shed aeciospores, they turn powdery and bright orange. In black raspberries, rusted leaves start to wither and drop in late spring to early summer. Orange rust is characterized by the proliferation of weak, spindly, and spineless shoots from infected roots, and floricanes produce no flowers. Orange rust does not kill plants, but its systemic infection causes considerable reduction in fruit production and vegetative growth. Plants rarely recover, and the disease cannot be controlled by fungicides so some degree of control is affected by removing

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plants. Attempts to introgress resistance from red raspberry into black raspberries may be warranted for areas where this disease is a problem. 17. Cane and Leaf Rust. Kuehneola uredinis (Link) Arth. is a pathogen of blackberries that occasionally affects red and black raspberries during wet spring conditions. It is important in blackberries in the southeastern United States and in the Pacific Northwest, and it is also found in New Zealand. This disease is first seen in late spring on infected floricanes, which develop large yellow uredinia that split the bark. In summer, they also are found on the underside of leaves, sometimes causing early leaf drop when infection is severe. Infection of fruit also may occur but is uncommon. Infected plants may also be prone to winter damage in colder climates (Ellis et al. 1991). This disease is not considered of sufficient importance in raspberries for considering screening or breeding for resistance. Minor rust diseases are also reported in the Arctic: Pucciniastrum arcticum Tranzschel, which affects R. arcticus, R. saxatalis L., and R. pubescens Raf.; R. triflorus Richardson and Phragmidium arcticum Lagerh., which affects R. arcticus and related fruits; in the subtropics, Hamaspora longissima (Thu¨m.) Ko¨rn., which has not been reported to attack raspberries (Ellis et al. 1991). G. Resistance to Bacterial Diseases Three bacterial diseases have been recognized to have economic significance in raspberries: crown gall (Agrobacterium tumefaciens [E.F. Smith & Townsend] Conn); fire blight (Erwinia amylovora [Burr.] Winslow et al.); and Pseudomonas blight (Pseudomonas syringae van Hall) (Finn 2008). 1. Crown Gall. This disease is common throughout the world in raspberries. It is most important as a disease in propagation from where it can be spread into commercial plantings. Once crown gall infestation occurs in soils, it may remain present for an extended length of time and can infest new plantings. In a commercial nursery where the same soil is repeatedly used, there can be considerable buildup of infestation. In British Columbia, there is a zero tolerance for crown gall at the foundation and certified level in commercial nurseries, where inspection is done at digging or when plants are being prepared for sale (Buonassisi et al. 1989).

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Crown gall is often routinely combated by dipping seedlings and healthy plants into a suspension of Agrobacterium radiobacter, a close relative of A. tumefaciens, sold in New Zealand as Dygall (Parker 1978). However, some authors have reported that this is not effective with raspberries (Burr et al. 1993). Raspberry cultivars have shown variable response to this disease (Keep 1989; Swait 1980). In the United Kingdom, ‘Malling Jewel’ and ‘Malling Orion’ showed a low level of infection while ‘Malling Delight’ and ‘Glen Clova’ showed considerable infestation (Swait 1980). In North America, ‘Willamette’ was highly resistant while ‘Skeena’ showed a high level in infestation (Daubeny 1986). ‘Meeker’, ‘Chilcotin’, ‘Haida’, and ‘Algonquin’ also were susceptible in a pot study, but they gave no problems either with propagators or in the field. ‘Skeena’ derivatives ‘Chilliwack’ and ‘Comox’ also have shown a high degree of susceptibility in New Zealand (H.K. Hall, pers. observ.). In New York State, galls have been observed on the black raspberry cultivar ‘Mac Black’ (C. Weber, pers. observ.). 2. Fire Blight. This bacterial disease is uncommon in raspberries, but it has been reported from Alberta, Illinois, Maine, New Brunswick, North Carolina, Nova Scotia, and Wisconsin (Braun et al. 1999). This disease has not been a major problem in Canada, but at times it has caused considerable damage and crop loss. In Nova Scotia and New Brunswick in the 1990s, this disease became a significant problem to growers, most often where it severely affected plantings of the selection K81-6, which was released in 1991, but it did not attack ‘Nova’ or ‘Festival’, sometimes prompting removal of K81-6 from commercial plantings (Braun et al. 1999; Jamieson 2000). Incidences of fire blight on K81-6 have also been observed in New York State (C. Weber, pers. observ.). In Alberta, this disease was associated with ‘Boyne’, completely wiping out a crop, but it did not affect neighboring plants of ‘Honey Queen’ (Evans 1996). Selection for fire blight resistance among raspberry showed that several clones were highly resistant (Braun et al. 1999). A subsequent study showed continuous variation of raspberry cultivars from the resistant ‘Royalty’ and ‘Nova’ to the highly susceptible ‘Prelude’, ‘K81-6’, ‘Encore’, and ‘Glen Magna’. Increased resistance appears to be associated with reduced succulent growth at cane and lateral tips and with the propensity to produce reduced amounts of exudates, reducing the spread in conditions favoring the disease. In northeastern North America, it appears that screening for resistance to this disease will prove valuable to reduce the chance of crop losses through fire blight.

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3. Pseudomonas Blight. This is a minor disease of raspberry, caused by infection with Pseudomonas syringae, a gram-negative, non–sporeforming, rod-shaped bacterium. This disease occurs in western Oregon, Washington State, and the southwest corner of British Columbia in the west of North America and in the Edmonton area of Alberta. A similar disease has been reported in Yugoslavia on cultivated and wild red raspberries (Ellis et al. 1991). Symptoms appear in spring as brown, water-soaked spots on young growth. Spots enlarge and blacken, and brown streaks extend from the blackened tips into vascular tissues. Laterals often blacken and die, and new growth maybe be killed to ground level by a virulent strain of the pathogen. Some control is possible by using application of copper sprays and by refraining from using excessive nitrogen fertilizer. There is a high level of resistance in ‘Chilcotin’, ‘Newburgh’ ‘Nova’, and ‘Viking’. ‘Nootka’ is highly susceptible, and ‘Skeena’ and ‘Chilliwack’ have moderate susceptibility. ‘Sumner’, ‘Matsqui’, and ‘Fairview’ showed some resistance; ‘Meeker’, ‘Willamette’, ‘Comox’, ‘Haida’, and ‘Centennial’ had moderate resistance (Ellis et al. 1991). No active work is being carried out to incorporate resistance for this disease into new raspberry cultivars. 4. Other Bacterial Diseases. Another gram-negative bacterium has also been implicated in plant death during the weaning-off phase of tissue culture propagation of raspberries. No information is available on possible resistance or the identity of the pathogen (H.K. Hall, pers. observ.). H. Resistance to Pests Many pest species attack raspberries, including insects, mites, and nematodes. Like fungal diseases, these attack all areas of the plant and are damaging at various stages of their development. Pests attacking roots include several weevils: black vine weevil, Otiorhynchus sulcatus (F.); clay colored weevil, O. singularis (L.); strawberry root weevil, O. ovatus (L.); rough strawberry root weevil O. rugosostriatus (Goeze) (Tanigoshi and Bergen 2002); O. armadillo, O. apenninus (Gordon et al. 2003); obscure root weevil, Sciopithes obscurus (Horn); raspberry brown beetle, Sericoides viridis (Solier) (Devotto and Gerding 2005); Fuller rose beetle or weevil, Asynonychus cervinus (Boheman) (Gerding et al. 2008); root lesion nematodes, Pratylenchus penetrans (Cobb), P. vulnus (Allen and Jensen), and P. crenatus (Loof); dagger nematodes, Xiphinema americanum (Cobb),

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X. diversicaudatum, and X. bakeri (Williams); needle nematodes, Longidorus elongatus (de Man), L. macrosoma (Hooper), L. attenuatus (Hooper), and L. diadecturus (Eveleigh and Allen). Pests attacking crowns include the raspberry crown borer, Pennisetia marginata (Harris), and strawberry crown moth, Synanthedon bibionipennis (Boisduval). Pests that attack fruit and flowers include the Japanese beetle, Popillia japonica (Newman); green June beetle, Cotinis nitida (L.); rose chafer, Macrodactylus subspinosus (F.); tarnished plant bug, Lygus lineolaris (Palisot de Beauvois); common green capsid, Lycocorus pabulinus (L.); raspberry bud moth or raspberry moth, Lampronia rubiella (Bjerkander); New Zealand raspberry bud moth, Heterocrossa rubophaga Dugdale; picnic beetles, Glischrochilus quadrisignatus (Say) and G. fasciatus (Oliver); European raspberry beetle, Byturus tomentosus (De Geer) and American raspberry fruitworm, B. unicolor (Say) (Ellis et al. 1991); strawberry bud weevil or clipper, Anthomonus signatus (Say) and A. rubi (Herbst) (Gordon et al. 1997). Pests that attack foliage include two-spotted spider mite, Tetranychus urticae (Koch); raspberry leaf and bud mite, also known as dryberry mite in North America or raspberry mite in Europe, Phyllocoptes gracilis (Nalepa) (Ellis et al. 1991); redberry mite, Acalitus essigi (Hassan); orange tortrix moth, Argyrotaenia citrana (Fernald); oblique banded leaf roller, Choristoneura rosaceana (Harris); spotted cutworm, Xestia (L.) spp.; variegated cutworm, Peridroma saucia (Hubner); double dart moth, Graphiphora augur (F.); western winter moth, Operophtera occidentalis (Hulst) and other winter moth species O. danbyi (Hulst), O. bruceata (Hulst), and O. brumata (L.) (Ellis et al. 1991); raspberry sawfly, Monophadnoides geniculatus (Hartig); small raspberry sawfly, Priophorus morio (Lepeletier); and raspberry leafmining sawfly, Metallus pumilus (Klug). Several aphid species attack raspberries. In North America these include the American large raspberry aphid, Amphorophora agathonica (Hottes), A. sensoriata (Mason), and small raspberry aphid, Aphis rubicola (Oestland). In Europe the species include the European large raspberry aphid, Amphorophora idaei (Borner) and the small raspberry aphid, Aphis idaei (van der Goot) (Ellis et al. 1991). Pests that damage canes include: the rednecked cane borer, Agrilus ruficollis (Fabricus); raspberry cane maggot, also known as the raspberry maggot or the loganberry cane fly, Pegomya rubivora (Coquillett); raspberry cane midge, Resseliella theobaldi (Barnes); raspberry cane borer, Oberea bimaculata (Olivier); blackhorned tree cricket, Oecanthus nigricornis (Walker); rose scale, Aulacaspis rosae

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(Bouche); and stalk borer, Papaipema nebris (Guenee). Pests that contaminate machine-harvested fruit include cutworms, Noctuidae; several species of weevils, Curculionidae; stinkbugs, Pentatomidae; leafrollers, Tortricidae earwigs, Forficulidae; and spiders (Menzies and MacConnell 1998). 1. Aphids. Amphorophora idaei (Fig. 29) and Amphorophora agathonica are significant aphid vectors of important viruses that infect raspberry in Europe and North America. The most important aphid species found on raspberry in the United Kingdom and northern Europe is the large raspberry aphid, Amphorophora idaei (Bo¨rner), a vector of raspberry leaf spot virus (RLSV), raspberry leaf mottle virus (RLMV), black raspberry necrosis virus (BRNV), and Rubus yellow net virus (RYNV) (Jones et al. 2001a). The North American large raspberry aphid, A. agathonica Hottes, is principal vector of the raspberry mosaic virus complex (RMV), which is caused by a complex of two to four of the above viruses. Breeding efforts have concentrated on resistance to the vector rather than the diseases themselves, and aphid resistance has become a major objective in breeding programs in both Europe and North America (Keep 1989). Eggs are laid near the base of primocanes and hatch in the spring. Several generations are produced by parthenogenesis during the summer, and some migrate to new feeding sites. The number of asexual generations has been greatly increased by growing raspberries in tunnels, providing a suitable environment for the pest for 10 to 11

Fig. 29. European large raspberry aphid (Amphorophora idaei). (photo by SCRI).

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months per year, instead of 5 to 6 months under field conditions. In summer-fruiting raspberries, peak numbers are usually found on primocanes close to harvest time. Winged males and sexual females are produced in late summer, and mate and lay eggs on the primocanes. Large populations can cause direct feeding damage to susceptible cultivars, but the aphids are of particular importance as vectors of at least four viruses that cause serious decline in plant vigor, productivity, and quality (Birch and Jones 1988; Jones 1986). Pesticides control aphid numbers but are ineffective in preventing the spread of viruses (Jones 1976). The introduction of raspberry cultivars containing genes for resistance has been very successful in plantations in controlling both aphids and the viruses they transmit (Jones 1976, 1979). In the United Kingdom, breeding for resistance to Amphorophora idaei using single major genes or polygenic minor genes has proven effective at controlling the vector since the 1960s (Birch et al. 2002). There are currently five biotypes of A. idaei in the United Kingdom. Briggs (1965) previously identified four biotypes of A. idaei, and several genes were identified that differ in their effectiveness against these biotypes. A further fifth resistance-breaking biotype was detected in the south of England in the late 1990s (Birch et al. 1997). The strongest forms of resistance, possibly immunity, to both A. idaei and A. agathonica are controlled by single dominant genes, enabling rapid and accurate selection of resistant progeny to be made. However, lower levels of resistance are under more complex genetic control, probably involving several genes, making selection difficult (Jennings 1963b). In the United Kingdom, sources of resistance to A. idaei (A1 , A10 ) have been derived mainly from North American red or black raspberry cultivars. In North America, the source of resistance to the endemic raspberry aphid species, A. agathonica, is from European red raspberry. This suggests that long-term coevolutionary battles between raspberry aphids and resistance genes in native species have occurred and that novel (nonendemic) resistance genes are more effective in plant breeding programs for pest resistance (Birch et al. 2002). Screening germplasm for aphid resistance is successful, providing the environmental conditions are suitable and control plants are included (Birch et al. 2002). Plants can be assessed in the field or in the glasshouse. To carry out the latter, small plants 8 to 10 cm tall are grown in an aphid-proof glasshouse during the growing season at 18 to 25 C and loaded with two or three adult apterous aphids. Plants are assessed 7 to 10 days later, reloading after 24 hr where aphids were deficient. Plants found free of aphid colonies are considered resistant and all others are considered susceptible (Jones et al. 2000).

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Raspberry cultivars containing genes for resistance to the large raspberry aphid have been in commercial use in the United Kingdom since the 1960s. Briggs (1965) demonstrated the genetic basis of resistance to the large raspberry aphid by showing that the virulence to the gene A1 (derived from R. idaeus) was a result of the inheritance of a single dominant allele. Gene A1 confers resistance to two biotypes and was bred into many cultivars, including ‘Malling Delight’ and Malling Landmark’ from EMR and ‘Glen Moy’, Glen Prosen’, ‘Glen Lyon’, and ‘Glen Ample’ from SCRI. By the early 1990s, Birch et al. (1994) showed that more than 75% of the aphid population had virulence genes that could overcome A1 -based resistance. The A10 gene, derived from R. occidentalis, confers resistance to biotypes 1 to 4 of A. idaei and was bred into many EMR cultivars, including ‘Malling Leo’, ‘Malling Joy’, ‘Autumn Bliss’, and ‘Gaia’, then from SCRI ‘Glen Rosa’ and more recently ‘Glen Doll’ and ‘Glen Fyne’ (SCRI 9062E-1) (Jennings et al. 2008). In the 1990s, aphids were found in southern England on genotypes with A10 , suggesting there was a fifth resistance-breaking biotype of A. idaei. This prompted a search for a new source of resistance. The East Malling cultivar ‘Octavia’, released in 2002, combines genes A10 and AK4a , from Germany, with the intention of conferring a more robust resistance (Knight and Ferna´ndez Ferna´ndez 2008a,b). Birch and Jones (1988) and Jones et al. (2000) established that cultivars with the same resistance gene appear to differ in their response in the field and in glasshouse-based tests. Cultivars with A1 from SCRI, ‘Glen Moy’ and ‘Glen Prosen’, were less resistant than those bred at EMR, ‘Malling Delight’ and ‘Malling Landmark’. This suggested that the genetics for resistance/susceptibility to aphids is more complex than previously assumed and that the effects of single dominant genes are modified by diverse ‘‘background’’ genes and by the plant’s environment during growth. This may explain the long durability of some single major genes and the shorter durability of the same gene in other cultivars or other resistance genes. ‘Glen Clova’, which confers only minor gene resistance to A. idaei, has remained durable for several years, and it reduces spread of RVCV significantly (Jones and McGavin 2004a) The mechanism of resistance in ‘Glen Clova’ is different from that conferred by genes A1 and A10 , since the former (minor gene resistance) involves mainly antibiosis (reduced fecundity) while the latter (A1 and A10 based) involves both antixenosis (reduced settling during host acceptance) and antibiosis (Birch and Jones 1988). A study carried out by Jones and McGavin (1998) to investigate infectibility of U.K. cultivars harboring A1 or A10 with several viruses

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found that none of the genotypes was immune to the viruses transmitted by A. idaei. In Canada, Stace-Smith (1980) showed that A. agathonica acquires virus more readily from A. agathonica– susceptible cultivars than from resistant ones. Therefore, control of these viruses continues to be dependent on effective resistance to the aphid vector. Elsewhere in Europe, German-bred cultivars ‘Rucami’, ‘Rumiloba’, ‘Rusilva’, and ‘Rutrago’ were shown to inherit resistance from ‘Klon 4a’ (gene AK4a ) (Bauer 1980; Daubeny 1994). ‘Rubaca’ (‘Rutrago’  ‘Latham’) also may carry resistance through this gene. With the breakdown in natural resistance and the threat of virus infection, there is now a great urgency to identify and incorporate new aphid resistance genes into the U.K. breeding programs. The last major resistance gene A10 has been overcome in England and at least one isolated and sporadic case in Scotland. Cultivars with more than one source or mechanism of resistance will be less likely to show genetic breakdown with the appearance of virulent aphid biotypes (Birch et al. 2002; Daubeny 1980). A more robust source of resistance may come from combining existing genes—for example, major gene(s)  minor gene resistance (Birch et al. 2002)— particularly with the support of molecular markers under development at East Malling Research (Sargent et al. 2007). Natural predators of parasitoids can keep numbers low, but this is an unreliable control method. In addition, contamination from parasitized aphid mummies on the ripe fruit or from predators dislodged from leaves of primocanes during harvest can cause significant economic losses. A breakdown of natural plant resistance against aphids means that pesticide applications are required to prevent spread of virus and direct damage due to aphid feeding, honeydew production, and fruit contamination. Resistance to A. agathonica in North America was based on a single dominant gene, Ag1 , from the European red raspberry cultivar ‘Lloyd George’ (Daubeny and Stary 1982) and was incorporated into many North American cultivars. This source of resistance has been effective for more than 50 years as a means of controlling aphid populations and the spread of viruses they transmit. It was concluded that diverse and virulent biotypes of the aphid have either not become established or occurred at all (Daubeny 1980); however, at PARC-BC, R. strigosus was incorporated into the breeding program in anticipation of possible resistance-breaking biotypes (Daubeny 1986). A new biotype, able to reproduce on cultivars with Ag1, was first observed in the 1990s, but it has not emerged as a major component of the raspberry aphid populations in the area (Martin 2002b). Many aphid-resistant cultivars

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have been released from the program; ‘Haida’ (Plate 5L), ‘Nootka’ (Plate 5K), and ‘Skeena’ (Plate 5L) are immune. ‘Chilcotin’ (Plate 5L) is susceptible to the aphid but appears resistant to the RMV virus, also ‘Willamette’ (Plate 5L) is susceptible to the aphid but remains free of the virus in Pacific Northwest plantations (Martin 2002b). More recently ‘Chemainus’ (Plates 5B and D), ‘Esquimalt’ (Plate 5J), ‘Nanoose’ (Plate 5A), and ‘Saanich’ (Plates 5C and E) have been released with aphid resistance and improved agronomic traits (H.A. Daubeny pers. comm.; Kempler et al. 2005a, 2006, 2007). Small Raspberry Aphids. The European small raspberry aphid, Aphis idaei, is widely distributed in southern and central Europe and is responsible for the spread of raspberry vein chlorosis virus (RVCV) (Jones and McGavin 1998). Some genotypes have a high level of resistance to this species, but it has not been possible to transfer this resistance reliably into new resistant cultivars (Jones and McGavin 2004a). Spread of RVCV may be avoided by selecting genotypes with immunity to the virus, which may be derived from the North American red raspberry cultivars ‘Canby’, ‘Cuthbert’, ‘Latham’, ‘Newburgh’, and ‘Viking’ and black raspberry cultivars ‘Cumberland’, ‘Munger’, and ‘Plum Farmer’ (Jennings and Jones 1986). This aphid is becoming more prevalent farther north in cooler climates where production has turned to protected cropping systems (Jones and McGavin 2004b). Partial resistance has been recorded to A. idaei in Germany, where the cultivars ‘Ontario’ and ‘Rubin’ showed strong resistance (Baumeister 1961). A. idaei and RVCV were both introduced to Canada through propagation stock (Jones 1986). The American small raspberry aphid, Aphis rubicola, is responsible for the transmission of raspberry leaf curl virus (RLCV) and is found only in North America, primarily east of the Rocky Mountains (Martin 2002b). Little resistance-breeding has been done for Aphis vectors, partially because they are difficult to handle and culture (Jennings 1988). A better approach for breeding to escape problems with the viruses transmitted by these aphids is likely to be through breeding for virus resistance. Other Aphids. Amphorophora sensoriata, a very pale slightly bluish green aphid, is common on black raspberry in the eastern United States. The cultivars ‘Canby’, ‘Titan’ (Plate 3D), ‘Lloyd George’, and ‘Royalty’ (Plate 3C) are resistant to feeding by this pest, and resistance could be bred into the black raspberry from these sources (Ellis et al. 1999).

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2. Cane Midge. Feeding damage caused by raspberry cane midge (Resseliella theobaldi) larvae predisposes raspberry canes to the disease known as midge blight, which is responsible for major losses in raspberry in many parts of Europe (Woodford and Gordon 1978), now extending into Siberian Russia (Shternshis et al. 2002). In most of Europe, midge larvae only colonize splits in the bark of primocanes, but in Scandinavia, larvae have been reported from splits in fruiting canes of the cultivars ‘Veten’ (Ellis et al. 1991) and ‘Ottawa’ (Dalman 1986). Similar damage has been reported in ‘Meeker’ and ‘Willamette’ grown in Serbia (Gordon et al. 2005). Larvae overwinter in cocoons in the soil at the base of the canes, where they pupate before emerging in the spring as adults, reddish brown midges 1.4 to 2.1 mm long (Ellis et al. 1991). Mated females lay eggs in splits and wounds in the bark at the base of the primocanes. The larvae hatch and feed in the outer cortical tissue protected by the covering of bark and, when fully fed, drop to the soil and pupate. Second and subsequent generations follow during the summer and early autumn. The number of generations varies between two and four, depending on the season and location. If the first generation finds adequate feeding sites and develops successfully, the second generation can be very large. The direct damage caused by midge larvae feeding is superficial, but the feeding sites become infected by a range of fungi (including Leptosphaeria coniothyrium, Didymella applanata, Phoma, and Fusarium spp.) (Williamson and Hargreaves 1979), resulting in the disease complex midge blight. In Germany, Fusarium avenaceum is involved with midge blight, causing significant damage as well as cane blight (Weber and Entrop 2007). The first-generation feeding sites may develop cankers, which leave the primocanes weakened and prone to damage by pickers, machinery, or strong winds. Damage from subsequent generations can be more serious because large populations are produced and fungi that colonize the sites penetrate and damage the cork layer. In mature plantations with a high inoculum of cane blight (L. coniothyrium), the characteristic patch lesions may be masked by spreading stripe lesions. Williamson (1984) confirmed that cane blight can be one of the fungi involved in the midge blight disease complex, but not in every outbreak. Therefore, the patch lesions are the most reliable indicator of the damage caused by cane midge. Affected canes continue to grow normally for the duration of the season without showing any visible symptoms. If patch lesions are extensive and girdling is common, a large proportion of the canes fail to produce flowering laterals the following spring, or they wilt and die

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before harvest, but unlike Phytophthora root rot symptoms, new primocane growth is unaffected. Although fungi are involved in this complex, fungicides have never controlled midge blight successfully. Instead, effective control relies on reducing numbers of first-generation midges to avoid the risk of secondgeneration larval feeding when the most economic damage occurs. This can be achieved by accurate timing of insecticides or by cultural methods to eliminate oviposition sites. The current control strategy in the United Kingdom and other European countries is to apply highvolume sprays of organophosphate insecticides, targeted to the basal 20 to 40 cm of the canes, when the midge begins to lay eggs in the spring (Woodford and Gordon 1986, 1988) although, with the reevaluation of pesticides in the United Kingdom and Europe, organophosphate-based insecticides are likely to be withdrawn in the near future and suitable alternatives must be sought (Gordon et al. 2005). Recent research in Serbia has shown that midge blight may be controlled with the use of Bacillus thuringiensis (Bt) var. israeliensis, either on its own or in combination with other biological preparations (Shternshis et al. 2002). As part of the RACER project (Reduced Application of Chemicals in European Raspberry production), a predictive model was tested that uses the relationships between the historical dates of emergence of overwintered cane midge and local meteorological data to give accurate forecasts of cane midge emergence in localized areas. This model, developed in the United Kingdom and tested at geographically distinct locations in Europe, now allows growers in the United Kingdom and northern Italy to obtain forecasts to time chemical application based on local meteorological information and is currently undergoing finetuning for use in other European countries (Gordon et al. 1989, 2002; Birch et al. 2003). Cane midge can also be controlled by cultural methods to eliminate egg-laying sites. The use of desiccant herbicides in the spring removes the first flush of primocanes of vigorous cultivars. This treatment stimulates the production of replacement canes that remain free of splits during the first-generation oviposition period. If no alternative oviposition sites are present, the population declines rapidly (Williamson et al. 1979). However, cultivars differ markedly in their ability to produce replacement canes, and serious yield losses may result despite the reduced pest attack. In Finland, primocane control in the cultivar ‘Ottawa’ resulted in control of cane midge and midge blight. Removal of the second flush of primocanes further decreased midge numbers, but there was significant reduction in subsequent cane growth (Dalman 1991). Alternatives to cane vigor

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control as means of control of midge and midge blight were examined by Woodford and Gordon (1988), including the addition of mulches and mechanical flailing devices to reduce midge damage. Some cultivars show more cane splits than others, and selection of genotypes that show little tendency for bark splitting has potential to be an effective means of resistance. However, breeding for resistance is difficult as the extent and timing of splitting in a genotype can vary from year to year, as can midge populations and infestation. ‘Glen Prosen’ and the hybridberries ‘Tayberry’ and ‘Loganberry’ do not readily split their rinds in the spring and are rarely infected by midge blight because females are unable to find suitable oviposition sites unless they are caused by mechanical means. Observations in Siberia have shown that ‘Vera’ escapes attack by cane midge, and similarly ‘Rumiloba’ has been found to be resistant in Northern Italy, but as yet the mechanism of avoidance is unknown (Gordon et al. 2005, H.K. Hall, pers. observ.). Other cultivars with few natural splits include ‘Norfolk Giant’, ‘Malling Landmark’, ‘Phoenix’, and ‘Muskoka’ (Keep 1989). Kichina (1977) reported resistance to cane midge from four wild species, R. anatolicus, R. caucasicus, both blackberries, R. odoratus, and R. crataegifolius the latter regarded as a potential donor of resistance. McNicol et al. (1983) noted that R. parviflorus, a close relative of R. odoratus, may also be a potential donor. Hybrid populations of red raspberry with R. crataegifolius and R. parviflorus were produced for evaluation. Hybrids of R. crataegifolius  R. idaeus were found to be resistant when exposed to raspberry cane midge. Histological examination of midge-infested wounds revealed that, in resistant genotypes, natural splits are repaired rapidly by a wound periderm that heals over the split, often enveloping developing midge larvae. 3. Raspberry Beetle and Raspberry Fruitworm. Raspberry beetle, Byturus tomentosus De Geer, is a major pest of cultivated raspberry and hybridberries in the many countries of Europe and frequently found in fruits of wild raspberry and blackberry (Gordon 1983; Keep 1989). The beetles overwinter in the soil at the base of the host plant and emerge in the spring, usually before the flower buds have opened. Adults are oval, golden brown, and 3.5 to 4.5 mm in length and feed extensively on the leaves as they expand, leaving longitudinal holes in the foliage (Jennings 1988; Taylor and Gordon 1975). In warmer locations, before raspberry flower buds open, adults fly to other Rosaceous plants such as apple (Malus domestica), plum (Prunus domestica), cherry (Prunus spp.), and hawthorn (Crataegus spp.) to feed on open flowers before returning to raspberry to breed on open flowers.

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Adults can damage the buds and flowers by feeding in the spring and early summer, but the greatest damage is caused by the larvae, which hatch from eggs laid on styles or anthers and browse on the surface of drupelets then burrow into the receptacle to feed on the developing fruit. Fruit is contaminated by the presence of larvae, leading to rejection or downgrading of the crop for both fresh and processing markets. In addition, damaged fruit can become infected by Botrytis gray mold, further increasing postharvest losses (Woodford et al. 2002). In commercial plantations, control usually involves application of pesticides just before the first flowers open to kill adult beetles before oviposition, followed by a second spray between green and pink fruit to coincide with the second flight of the pest. The use of insecticides close to fruit harvest is becoming increasingly unacceptable because of the risk of residues in the fruit. Strategies have been developed to target chemical application based on adult beetle activity in the crop (Woodford et al. 2000). One approach advocated to reduce spraying is the use of trapping to establish the level of pest infestation, followed by a decision on whether to spray according to an established threshold (Lovelidge 2001; McGrath 2000). Studies of insect behavior and plant chemistry have shown that adult beetles are strongly attracted to raspberry flower volatiles (Birch et al. 1996; McGrath 2000; Woodford et al. 1992, 2003). This information has been used in ongoing research to develop traps in combination with volatile floral attractant lures to monitor numbers so routine chemical applications can be replaced by more targeted spraying and possibly lead to mass trapping of beetle populations as a form of integrated control (Birch et al. 1996; Gordon et al. 1997; McGrath 2000; S.C. Gordon, pers. comm.). Little is known about the mechanisms of resistance to raspberry beetle, although it is known that flower volatiles are involved in host attraction and acceptance (Birch et al. 1996). As yet, no red raspberry cultivars with resistance are available. Strong resistance in R. phoenicolasius and R. kuntzeanus (R. innominatus var. kuntzeanus) was found to be transmitted to F1 hybrids in crosses with red raspberry (Keep 1989; Rietsema 1936). Laboratory tests at SCRI showed that flower buds of R. coreanus, R. cockburnianus, R. phoenicolasius, and R. thibetanus showed resistance but the adults fed to various degrees on the young leaves (Gordon and Jennings 1972). Jennings et al. (1977) found the leaves of the black raspberry ‘Munger’ are highly resistant to raspberry beetle. Briggs et al. (1982) established that the strongest source of resistance can be found in R. phoenicolasius, and derivatives of R. coreanus and R. crataegifolius showed low levels of damage.

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The American (B. unicolor) and European (B. tomentosus) raspberry beetle species share similar life histories and habitats, although taxonomically the American fruitworm is closer to the Asian species, B. affinis than to the European beetle (Malloch and Fenton 2003). In North America four regional isolates of raspberry fruitworm with similar appearance and life cycle, causing similar damage, were originally given separate taxonomic status as B. backeri, the western fruitworm, B. rubi, the eastern fruitworm, B. sordidus and B. unicolor. However, Springer and Goodrich (1983) reexamined specimens and concluded that the four species represented color phases of a variable species and placed them all in a single species as Byturus unicolor Say (Malloch et al. 2001). However, phylogenetic studies on Byturidae presented evidence that specimens of B. unicolor from Washington, Illinois, and Ohio are distinct from one another and possibly represent different species (Malloch and Fenton 2003). The raspberry fruitworm is a key contaminant of machine-harvested raspberries in Washington State, where strict contaminant tolerances exist depending on the berry grade that is harvested. WSU has developed a monitoring technique using sticky traps that will help growers assess when to spray, based on spraying thresholds for different processing grades (MacConnell 2005). In extensive evaluations of susceptibility, Schaefers et al. (1978) concluded that ‘Cuthbert’ was less susceptible to attack and relatively low bud damage was found in ‘Taylor’, ‘Viking’, and ‘Royalty’. However, fruit of each of these cultivars was susceptible, and the lowest percentage of fruit damage in 1975 was still more than 10%. Black raspberries may have some resistance as it is reported that the pest prefers purple and red raspberries (Funt et al. 2007). Further assessment of black raspberries as a source of resistance to both the European and North American species is recommended. 4. Cantharid Beetle. Cantharus obscura L. is a sporadic, localized pest of raspberry in eastern Scotland, which, when present, causes widespread damage to a plantation. Adults cause extensive feeding damage to expanding laterals early in the growing season by tunneling from the apical end on the bud, exposing the pith. Laboratory studies show that damage was confined to cultivated raspberry and, to a lesser extent black raspberry. Several cultivated blackberries, wild blackberry and wild R. idaeus were not damaged (Gordon and Woodford 1994). Little is known about the biology or why it has become a pest. Growers obtain adequate control of this insect with organophosphorus insecticide (Gordon et al. 1997).

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5. Weevils. Many weevils can be found on Rubus and can cause damage to roots and foliage and also act as a contaminant in machineharvested fruit. The life cycles of wingless weevils are similar. Most species consist solely of parthenogenic females, which feed nocturnally and shelter in the soil or foliage during the day. Adults emerge in spring or early summer, when there is a period of intense feeding followed by egg-laying. The larvae feed on plant roots until the following spring, when they pupate before emerging as adults. A single weevil may lay several hundred eggs in a lifetime, and there is often overlap between generations (Tanigoshi and Bergen 2002). Clay-colored Weevil. Otiorhynchus singularis L. (Fig. 30) is commonly found in raspberry plantations in North America, Europe, and the United Kingdom but is a particular problem in plantations in eastern Scotland (Gordon and Woodford 1986) and in Washington State (Tanigoshi and Bergen 2002). In Scotland, DDT controlled clay-colored weevil effectively, but it has become a problem in commercial plantations since the withdrawal of the chemical in the 1970s. Damage is most obvious in the spring and summer, when adults feed on the young buds and fruiting laterals. A high proportion of the laterals may be damaged and fruit yields reduced in heavily infested plantations (Gordon and Woodford 1986). Synthetic pyrethroid insecticides are now used to control this pest (Gordon et al. 2005). Black Vine Weevil. O. sulcatus F. (Fig. 31) causes damage in many small fruit and ornamental crop species, mainly by larvae feeding on the roots. Characteristic notching around the outside of leaflets is an

Fig. 30. Clay-colored weevil, Otiorhynchus singularis. (photo by SCRI).

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Fig. 31. Black vine weevil (Otiorhynchus sulcatus [F.]). (photo by SCRI).

indication of vine weevil in a plantation. Vine weevil larvae damage rootlets and cambium tissue of larger roots near the soil surface from autumn through to early spring. Although raspberry can tolerate higher levels of black vine weevil larvae feeding on roots than other species (Booth et al. 2002), this foraging activity may cause stunting and reduced yield. Observations in the United Kingdom suggest that vine weevils reduce vigor in raspberries growing adjacent to heavily infested strawberry plots and in protected plots (Gordon et al. 1997). In North America, machine harvesting causes adult weevils, among other arthropods, to fall off with ripe berries and become a serious contaminant of the harvested fruit. Monitoring systems have been developed to assess weevil activity in commercial plantations to facilitate control (Gordon et al. 2002). Entomopathogenic nematodes are used as biological control in Europe and North America, although efficacy is limited by cool soil temperatures in cooler climates (Booth et al. 2002; Haukeland 2006). Other integrated control strategies include the use of poultry and game birds (pheasant and partridge) to feed on adults in a plantation (Gordon et al. 1997), but this is not recommended due to food safety issues. Breeding for resistance to weevils is also a possibility (Cram and Daubeny 1982). Black raspberry and blackberry almost never suffer visible damage from root feeding larvae (Ellis et al. 1991). Cram and Daubeny (1982) found that the cultivars ‘Malling Leo’ and ‘Glen

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Prosen’, both derivatives of black raspberry, have an effect on the reproduction cycle of weevil, and suggested these as a possible source of resistance. For the long-term future of raspberry production in some areas, investment in breeding for resistance to weevils is essential to reliably control these pests, especially if organic production is desired. Strawberry Bud Weevil. Anthonomus signatus Say or ‘‘clipper’’ is a weevil native to eastern North America that attacks Rubus. Females lay a single egg inside the bud and then girdle the pedicel so that the severed bud hangs or drops to the ground, at times causing considerable losses in production (Ellis et al. 1991). The strawberry blossom weevil (A. rubi Herbst) causes similar damage in Europe and some regions of the former USSR (Gordon et al. 1997). Studies in Switzerland show this pest reduces raspberry yield in that country (Carlen et al. 2004). Other weevils affecting raspberry in North America include strawberry root weevil (O. ovatus L.), the rough strawberry root weevil (O. rugosostriatus Goeze), and the obscure root weevil (Sciopithes obscurus L.). In Europe, O. armadillo and O. apenninus are also considered damaging to raspberry (Gordon et al. 2003). 6. Nematodes. Plant-parasitic nematodes of various species are found in raspberry plantings but only a few are associated with economic damage (Jennings 1988). For those species, damage to roots is proportional to the population density in the soil. Damage caused by extensive feeding produces stunting and deficiency symptoms from restriction of nutrient and water uptake. Roots are also damaged, shortened, and may show swelling or galls and necrotic lesions if nematodes enter the roots. Newly planted raspberries are particularly sensitive to nematode attack, and a heavy infestation often results in poor establishment. Nematodes have been recognized as a problem in Europe for over 100 years. Even by 1905 the effects of nematodes and nematode transmitted viruses were well documented there (Ellis et al. 1991). Since that time it has been established that there are four nematode-transmitted viruses in Europe and three in North America that can cause serious diseases in Rubus species (Martin 2002b). Pratylenchus species, associated with declining red raspberries in Canada, were reported in the mid-1930s (Ellis et al. 1991). In the 1950s, several incidents of nematodes restricting raspberry growth in the United States and Canada were reported (Ellis et al. 1991; Goheen 1954). Threshold densities and management protocols have been established with some species of

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nematodes, but the importance of other species and their pathogenic and virus vector capabilities need still to be established. Root Lesion Nematode. Pratylenchus penetrans (Cobb) Sher & Allen is a pest that feeds on the root cortex of raspberries in Europe, North America, and Scotland, resulting in cell death, root lesions, and death of small and medium-size roots (Keep 1989). It is widely distributed in commercial plantings of raspberries in the Pacific Northwest and Scotland, often associated with areas of poor growth, root necrosis, and dying canes. It has also been associated with poor plant establishment and replant problems. Sterilization before planting or applications of nematocides before or after planting have greatly improved growth (McElroy 1977; Trudgill 1983). Control of nematode-borne viruses was considerably improved with the introduction of soil fumigants to reduce nematode populations before planting. However, the use of fumigation to reduce nematode levels may soon be difficult as chemicals are being removed from the market for environmental reasons. Research by the team at PARC-BC showed that nematode-resistant cover crops could reduce the levels of nematode infestation between the rows, but this did not alter the levels among the plants (Vrain et al. 1996). Use of these crops between plantings of raspberries does assist with the reduction of nematode levels for the establishment of a new crop, but this takes longer and is less effective than use of fumigation. Greenhouse tests with artificial inoculation with nematodes produced differential responses in at WSU, with resistant cultivars (‘Canby’, ‘Chilcotin’, ‘Cuthbert’, ‘Haida’, ‘Meeker’, ‘Newburgh’, ‘Nootka’, ‘Puyallup’, ‘Skeena’, and ‘Willamette’) showing no loss in weight, and susceptible cultivars (‘Latham’, ‘Glen Isla’, and ‘Matsqui’) showing significant loss of fresh weight (Bristow et al. 1980). Similar tests in the PARC-BC program showed ‘Nootka’ to be the most resistant and ‘Glen Clova’ and ‘Chilcotin’ the most susceptible (Vrain and Daubeny 1986). In a subsequent study of inheritance of nematode resistance, ‘Chilliwack’ was found to give rise to progenies tolerating higher levels of nematode infestation. In contrast, derivatives of the more resistant ‘Nootka’ and ‘Dalhousie Lake’ supported lower levels of nematodes, but showed greater growth reduction than the ‘Chilliwack’ derivatives (Vrain et al. 1994). There has been limited use of resistant clones in breeding new cultivars and a general reliance on fumigation to control nematodes (Martin 2002b). For the long term it will be necessary both to breed for increased nematode resistance and to use natural fumigation

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from use of cover crops to drop nematode levels in the soil before planting for sustained raspberry production in areas where nematodes are endemic. Dagger Nematodes. Xiphinema bakeri Williams, X. diversicaudatum (Micol.) Thorne, and X. americanum Cobb are other important nematode pests on raspberries. They are relatively large ectoparasitic nematodes up to 5-mm long for adults of X. diversicaudatum and 2-mm long for the other species. Long feeding stylets allow feeding deep in the tips of young roots and give rise to the name dagger nematode. Saliva from nematodes injected into roots stops growth and causes small galls to form (Jennings 1988). X. bakeri is widespread in British Columbia and has the greatest impact on root growth by root destruction and reduction in cane growth, even in relatively low numbers of 200 nematodes per liter of soil. X. americanum also occurs in North America but causes little direct feeding damage. X. diversicaudatum can cause damage through feeding on roots. It is widespread in Europe and Southern and Central Britain, with localized areas of infestation in Scotland, and is rare in North America. These two species do most damage as virus vectors for tomato ringspot virus (TomRSV) and for Arabis mosaic/ strawberry latent ringspot nepovirus (AMV/SLRV), respectively. Virus particles are selectively retained in the esophageal region of the vector nematodes during feeding on virus-infected plants, and the nematodes may remain infective for a year or more. However, the virus is not passed on to eggs or retained after molting but in feeding the virus is released into plant cells, initiating virus infection. 7. Mites. Tetranychid Mites. Several species of tetranychid mites (Family Tetranychidae) have been reported to damage raspberries worldwide (Ellis et al. 1991). Spider mites are arthropods with eight legs that resemble tiny spiders and are approximately 0.5 mm long when mature. They vary in color from straw to green or red with two darker spots on the upper surface of their body. The most common is the two-spotted spider mite, Tetranychus urticae Koch, which is able to feed on hundreds of cultivated and wild plants. Mites colonize raspberries in the early spring as leaves form. Eggs are laid, and they usually feed on the underside of raspberry leaves and reproduce to colonize new foliage as it appears. They produce very large numbers when the plants are grown in a warm, dry, or dusty environment, especially on susceptible genotypes when plants are

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under stress or under protection (H.K. Hall, pers. observ.). Feeding removes sap from the leaves causing them to turn yellow, silver, or bronze. Webbing is usually present on the lower surface of leaves, it can cover the plant when infestations are extreme. Infestations, when heavy, stunt canes and leaves; when severe, cause leaves to bronze and/ or drop leaves early. When this occurs, the plants are also more susceptible to winter damage. Yield and fruit quality also can be reduced. Primocane feeding can stunt new cane growth and cause yield reductions in the following year. Early application of insecticides, especially synthetic pyrethroids and carbamates, can kill beneficial insects and mite predators and perhaps stimulate mites to increase their reproduction, promoting a population explosion later in the season. Two-spotted mite is rare as a problem in cool areas such as Scotland but is increasing in importance as protected culture increases (Gordon et al. 2005). Control has largely relied on repeated application of a range of acaricides, but withdrawal of products and development of acaricideresistant mites has made effective chemical control difficult (Gordon et al. 2005; Linder and Planche 2006). Studies in Poland have shown fungicide programs used to control Botrytis cinerea in strawberry can reduce populations of mites (Labanowska and Meszka 2003). Biological control has been explored in several countries with varying degrees of success depending on the location, production system, and predator identified for control (Linder et al. 2003; Meesters et al. 1998; Tuovinen et al. 2000). However, mite populations have been successfully managed in Europe by introducing the two-spot spider mite predator, Phytoseiulus persimilis Athias-Henriot (Gordon et al. 1997). In Europe, as part of the RACER project, the use of naturally occurring predatory mites has been investigated in several countries. It has been discovered that native predatory mites were more effective in managing two-spotted spider mite numbers on raspberry in Finland, Italy, and Switzerland than introduced species (Tuovinen et al. 2000). Resistance and susceptibility are clearly visible among red raspberry cultivars and wild Idaeobatus species (Shanks et al. 1992; Wilde et al. 1991a). ‘Joan Squire’ sustained high population numbers and ‘Malling Leo’ low numbers, with ‘Glen Clova’, ‘Glen Moy’, and ‘Glen Prosen’ intermediate (Sonneveld et al. 1996). Obvious differences were also present in the WSU evaluation of resistance in red raspberries in a greenhouse trial (Gordon et al. 2005). Far lower levels were also found on R. parvifolius and R. parvifolius  red raspberry progenies and also the advanced raspberry selection WSU 968 (SCRI 6820/35 [a ‘Glen

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Prosen’ Sib]  ‘Algonquin’) and some of its seedlings (Gordon et al. 2005; Shanks et al. 1992). Raspberry Leaf and Bud Mite. The microscopic raspberry leaf and bud mite (adults 0.15-mm long), also known as the raspberry mite in Europe and dryberry mite in the United States, Phyllocoptes gracilis (Nalepa), occurs in many parts of the raspberry-growing world (Ellis et al. 1991). It is a pest at times in many parts of northern and central Europe, especially on wild raspberries growing in or on the edges of forest and other sheltered areas (Gordon et al. 2005). The most obvious symptom of this pest is yellow blotching of leaves, which occurs on all leaves when infestation is severe. The apical tip of the primocanes also may be damaged, and a proliferation of lateral buds is likely to result in weak, branched canes that are difficult to tie in during training. Less obvious manifestations of leaf and bud mite attack are early ripening of drupelets and malformed fruit that are difficult to pick, decreased yield, and general loss of vigor (Ellis et al. 1991; Gordon and Taylor 1977). Symptoms may be mistaken for viruses, resulting in plants being destroyed (Ellis et al. 1991). Spread is likely to be via wind currents or on insects but also may be through nursery propagation of plants. Control may be affected through the use of the predatory mite Typhlodromus pyri Scheut., which is a common predator in Scotland and Kent (Gordon 1981). Also, control through biennial cropping is an effective means of breaking the pest cycle. Severe infestation has been observed in protected plantations of ‘Glen Ample’ in the United Kingdom recently, and early indications show that ‘Glen Doll’ and ‘Octavia’ are also susceptible. Studies are under way to develop methods of control that could be used as part of an integrated system (S.C. Gordon, pers. comm.). Variation in levels of infestation have been observed, with ‘Malling Promise’, ‘Scho¨nemann’, and ‘September’ showing resistance that could be utilized for developing resistant cultivars (Gordon 1981; Gordon and Taylor 1976). 8. Raspberry Moth. Lampronia rubiella (Bjerkander) can cause severe damage in the early spring in raspberry crops in Europe. Eggs are laid in open flowers and early instar larvae feed on the receptacle. When fully fed, second instar larvae migrate to the soil, molt, and hibernate over the winter. In spring, the larvae emerge from the soil, climb canes, and burrow into axillary buds where they feed until they pupate. Control is by insecticidal sprays in early spring, and the use of a thick insecticidal

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application to cane bases to kill climbing larvae has potential (Gordon et al. 2005). Resistance to this pest is unknown. 9. Raspberry Cane Borer. Oberea bimaculata (Oliver) belongs to the family Cerambycidae, the long horn beetles, and is a native insect distributed over northeastern North America (Ellis et al. 1991). Adults are slender dark beetles about 1.25 cm long. After laying a single egg, the female girdles the cane 10 to 15 mm above and below the egg, causing the shoot tip to die. After hatching, the larvae bore downward in the cane where they overwinter just below the lower girdle. The next season the larvae bore until they reach the crown, where they spend a second winter. The following spring, larvae pupate. New adults emerge in summer, thus taking two years to complete the life cycle. This pest is minor and is not an economic problem. Control can be achieved by pruning just below the girdled point on the cane when the tip dies off. Resistance is unknown. 10. Raspberry Bud Moth. Heterocrossa rubophaga Dugdale (¼Carposina adreptella Walker) (Lepidoptera) is a native insect in New Zealand that lays eggs on raspberry plants, and its larvae attack the canes, young leaves, buds, and fruit (Langford and Snelling 1997). It also attacks native Rubus, blackberry, and other introduced Rubus species. In a commercial raspberry plantation, it may cause considerable damage, eating terminal buds, burrowing into the growing cane, and killing the shoot tip, causing branching and sometimes subbranch growth. In New Zealand, this pest is the most important pest of aerial tissues of raspberry (Wilde et al. 1991b). If infestation occurs early in the growing season, the new cane growth for next season may be devastated if pest levels are high. When cane growth has ceased, the plant is still susceptible to attack from the insect, which then will attack the cane buds on the quiescent or dormant cane. In the springtime, attack can occur on fruiting laterals and also on the developing fruit, rendering it useless and requiring infested fruits to be sorted from the marketable fruit. When infestation is delayed until fruit is ripening, the larvae feed on the receptacle and fill the inside of the fruit with frass. Fruit that is infested at this stage of maturity is very difficult to see when grading, and a low to moderate level of infestation renders the harvest uneconomic as each fruit has to be inspected to see if a budmoth is inside or if it has left evidence of its habitation. Control of budmoth is possible using Bacillus thuringiensis (BT), insect growth regulators, or organophosphates, but timing of spray application is important, especially with BT or insect growth regulators

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as it is difficult to kill larvae once they are inside the plant. The pheromone from the female insect has been isolated, and it is possible to effectively monitor and trap the male moths (Ferguson 1997; Foster and Thomas 2000). In the 1980s there was a severe infestation of budmoth in a block of selections in a New Zealand Department of Scientific and Industrial Research (DSIR) field at Lincoln. From over 50 selections all but 3 had severe infestation with budmoth attack in new cane growth and in ripening fruit. However, the remaining three clones were entirely or almost entirely free of attack, and none of the fruit was infested. These proved to be all from the same cross ‘Marcy’  ‘Columbian’ purple raspberry. This observation prompted further investigation, which showed that larvae placed on Rubus glaucus had 100% mortality. Larval death was almost as high when they were placed on the black raspberry, Rubus occidentalis. A further small reduction in mortality was also found when larvae were placed on purple raspberries (F1 hybrids of black and red raspberries) and on second-generation hybrids from the first backcross of purple raspberries to red raspberries, including the cultivars ‘Royalty’ and ‘Brandywine’ (Wilde et al. 1991b). In contrast, larvae placed on blackberries had no deaths, and when they were placed on susceptible cultivars of raspberries, mortality was only 5% to 8%. Subsequent breeding with budmoth-resistant selections has taken this resistance to the third and fourth backcross with minimal reduction of resistance. Fruits of these BC4 selections have lost the dark color and distinctive cooking aroma that comes from R. occidentalis. In practical terms in the field, the resistance eliminates fruit infestation and death of apical sections of cane growth, allowing normal cane growth and eliminating the requirement to inspect every individual fruit for infestation from an outbreak in the field. In trial plots when infestations were present, fruit from resistant selections was able to be poured straight into containers for sale (H.K. Hall, pers. observ.). There is potential for incorporation of a screening step for budmoth resistance in a New Zealand raspberry breeding program as budmoth have successfully been reared in a laboratory (Clare and Singh 1991). The moths have been placed in a cage to naturally infest seedlings, and feeding was observed on susceptible segregates (H.K. Hall, pers. observ.). The primary restriction on incorporation of this resistance into a breeding program in New Zealand has been financial and public breeding of raspberries for the good of the New Zealand raspberry industry has now ceased.

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11. Grass Grub. Costelytra zealandica (White) is another New Zealand native insect that is a major pest of raspberries. This pest attacks other Rubus species as well as most berryfruit crops, grasses, and fruit trees (van Toor and Dodds 1994). Grass grub larvae are voracious feeders on roots. In raspberries, a severe infestation of grass grub can consume all the root fiber of a plant as well as strip the bark of the roots up to the ground surface, killing the plant (H.K. Hall, pers. observ.). Control of this insect is difficult, but with blueberries, effective control is obtained by the incorporation of insecticide prills into the root medium or by sprays at the appropriate time to kill the insects. In addition, a soil bacterial pathogen of this pest, Serratia entomophila, has been developed as a commercial biocontrol agent, Bioshield grass grub (Ballance 2007). In raspberry seedling populations, there is considerable variation in susceptibility of the plants to grass grub. It appears that it will be possible to select for resistance to this pest and in the future incorporate it into new cultivars. 12. Double Dart Moth. Graphiphora augur Fabr. was first observed causing damage to raspberry plantations in eastern Scotland in the early 1980s and has not yet been observed in plantations elsewhere, despite its wide distribution throughout the United Kingdom. Damage occurs early in the season and is sporadic and localized, where all primary buds and expanding laterals are completely destroyed. In many cases, secondary and tertiary buds are unaffected and replacement laterals grow normally, but yield losses in infested plantations can be considerable and ripening is delayed (Gordon et al. 1990). Only small numbers of moth larvae are responsible for extensive damage No trials have been done to determine the best chemical for control, but applications of organophosphorus insecticides that control other raspberry pests are effective if applied early (Gordon et al. 1997). I. Resistance to Virus Diseases Freedom from virus diseases in raspberries is essential for vigorous healthy plants and production of a good quantity of high-quality fruit. Failure to attend to this issue by breeders and nursery producers of plants for commercial sales can rapidly lead to a decline in the local industry. Nursery production of plants needs to incorporate a virusfree, high-health program for production of superior nuclear stock for propagation and an inspection program for trueness to type and high

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health in the nursery. In some areas a commercial nursery must pass inspection before the plants can be certified, providing some protection for commercial growers using that source of plants. Utilization of high-health plants for commercial production results in significant yield increases (Ourecky 1975b). Breeding new cultivars for reduced or eliminated virus problems has concentrated on resistance of cultivars to the virus (virus resistance) or to the vector, usually aphids, nematodes, or leaf hoppers (host resistance). Viruses usually are grouped according to their vector. New techniques of detection are being used to find previously undiscovered viruses (Martin and Tzanetakis 2008). A newly discovered virus, black raspberry decline, has been shown to be very important in black raspberries in Oregon, causing plant death (Halgren et al. 2008). Red raspberry and blackberry cultivars have been found to be symptomless hosts and show no effects of infection. 1. Pollen and Seed Transmitted Viruses. Raspberry cultivars cannot be protected from pollen- and seed-borne viruses by resistance to a vector, mainly honey or bumble bees, for pollination. The most important pollen-transmitted virus found in raspberries is RBDV. This virus was responsible for the demise of ‘Lloyd George’ as a cultivar in Scotland and the rest of the United Kingdom (Barnett and Murant 1970). RBDV affects plants by reducing vigor, causing poor fruit set and crumbling of fruit, and it is transmitted by seed to progenies (Converse 1973; Murant et al. 1974). Infected plants can be freed from the virus by propagation of small cuttings that have been freed of virus by heat treatment (Mellor and Stace-Smith 1976). This is now routinely done by heat treatment and tissue culture propagation (Karesova et al. 2002). RBDV is found in most parts of the world where raspberries are grown, although the northeast of China appears RBDV free and some areas in Chile are free of the virus (Matus et al. 2008). In contrast, a more virulent, resistance-breaking strain of RBDV (RB-RBDV) is found in Russia, Serbia, and England. Other strains have been found in black raspberry and from collections in cultivars and wild types from around the world (Chamberlain et al. 2003; Jones et al. 2001b; MacLeod et al. 2004). In England and Wales, 12 different isolates were found from extensive testing (Barbara et al. 2001), suggesting that it will be worthwhile to do more detailed assessments of RBDV isolates from Australia, eastern and western Europe, New Zealand, and North America. A wide range of raspberry cultivars has been evaluated for susceptibility to RBDV, either by inoculation or by long exposure to natural infection. Nearly 70 named cultivars are resistant to the common strain of RBDV, presumably through gene Bu (Table 5).

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However, almost all can be naturally infected with the resistancebreaking strain RB-RBDV. There may also be some variation in resistance to the common strain or local variants of a less virulent strain. For example, ‘Glen Moy’ was not susceptible to RBDV in Scotland but was quick to become infected in New Zealand and the United States. ‘Sumner’ did not get RBDV in New Zealand, but it was thought that it had became infected at Puyallup, Washington. DNA testing has since shown that these RBDV-positive ‘Sumner’ plants were not true to type, although they were not able to be identified (P.P. Moore and Martin 2008). Worldwide, many of the currently important cultivars are susceptible to the common strain of RBDV. There is a constant threat of RBDV infection unless they are removed and replanted frequently, as with the DSA cultivars. In the Nelson area of New Zealand, ‘Marcy’, ‘Skeena’, ‘Glen Moy’, ‘Chilliwack’, ‘Comox’, ‘Autumn Bliss’, ‘Autumn Britten’, ‘Joan Squire’, ‘Tulameen’, and ‘Glen Ample’ quickly become infected and cannot be grown economically even when planted virus free. When RBDV arrived in New Zealand, pressure quickly became very high, due to the widespread use of the susceptible cultivar ‘Marcy’ for process production. Infection rendered it less vigorous, crumbly fruited, and unproductive. ‘Skeena’ was planted as the replacement cultivar for process production, and it also became infected very quickly. All the recent introductions of new floricane-fruiting cultivars from the HRNZ program are resistant to the New Zealand strain of the virus. As plantings of ‘Marcy’, ‘Skeena’, and other susceptible cultivars are removed and replaced, virus pressure will diminish in commercial plantings. Virus pressure in the WSU breeding program was previously very high, but when the program came under new management, many of the susceptible selections were removed. Virus pressure is maintained there by having a pot trial to evaluate new selections and other germplasm of interest (P.P. Moore and Martin 2008). In the PARC-BC program, a trial has been set up to promote infestation of seedlings by RBDV so that the selections can be used for a molecular biology approach in screening for RBDV resistance. However, the resources for carrying this project to completion may not be forthcoming. For both of these programs, breeding for RBDV resistance will be important for the future of the processing industry as the current major cultivar, ‘Meeker’, is susceptible, and the lifetime of plantings is getting shorter before crumbly fruit forces the field to be removed for replanting with virus-free plants. Development of raspberries resistant to the common strain of RBDV relies on being able to put high pressure on the plants in seedling fields

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and in selection blocks, so that susceptible selections will be screened out prior to completion of evaluation. This disease warrants both the investment in developing molecular markers for RBDV resistance and the cost of screening seedlings for resistance prior to planting in the field. Breeding for primocane-fruiting selections in the New Zealand program was very difficult in the early days of this work, due to RBDV infection. All initial selections were related to ‘Autumn Bliss’, ‘Autumn Britten’, ‘Glen Moy’, or ‘Zeva Herbsternte’. Without exception they all became infected with RBDV. RBDV-resistant primocanefruiting selections were then developed by intercrossing ‘Heritage’, ‘Kiwigold’, high-quality floricane-fruiting types that had some primocane fruit, and a selection from the cross ‘Autumn Bliss’  ‘Haida’. A range of RBDV-free material has been developed that shows promise for cultivar release in future. Breeding for RBDV resistance at EMR became very difficult when RBRBDV arrived in infected seed from Russia. Considerable resources have been required to screen and eliminate RBDV-positive plants from the breeding program. This is made very difficult as sampling has to be very thorough to pick up all infected sectors of plants when the virus is spreading through them from each infected flower. No reliable resistance to RB-RBDV is known, but a few cultivars, such as ‘Haida’ and ‘Scho¨nemann’, display some resistance to field infection. RBDV resistance has also been developed through molecular biology, resulting in engineered resistant clones of ‘Meeker’ raspberry. However, public distrust of this technology appears to limit the value of this material, and at present it appears that it will not become commercialized (Martin 2002a; Martin and Mathews 2001; Martin et al. 2004). Tobacco streak virus (TSV) and apple mosaic virus (AMV) also are transmitted by pollen and by seed. Infestation of raspberries is present in some regions, but as yet no information is available on their importance to plant health or productivity. However, virus presence is assumed to be detrimental, and propagation stocks should be freed of virus before bulk up and commercial release. Genetic resistance is the only long-term option to viruses with this mode of transmission (Ellis et al. 1991; Finn 2008). 2. Aphid-Transmitted Viruses. After RBDV and other pollentransmitted viruses, the most important viruses in raspberries are those involved in the raspberry mosaic virus complex (RMD), black raspberry necrosis virus (BRNV), raspberry leaf mottle virus (RLMV), raspberry leaf spot virus (RLSV), raspberry vein chlorosis virus (RVCV),

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and Rubus yellow net virus (RYNV) (Ellis et al. 1991). Hypersensitive reactions to RLMV and RLSV have been found in raspberries at SCRI which could be used to breed plants that died out when infected with these viruses (Jones and Jennings 1980). However, this approach has not been followed in breeding. Host resistance to the vectors has been used to withstand both European and North American aphid vectors of this disease. Breeding for vector resistance to this disease complex is therefore considered in the section on pest resistance. 3. Nematode-Transmitted Viruses. A range of nepoviruses (nematodetransmitted viruses) also have been found infecting raspberry or other Rubus, including Arabis mosaic virus (ArMV), cherry leaf roll virus (CLRV), strawberry latent ringspot virus (SLRSV), raspberry ringspot virus (RpRSV), tomato black ring virus (TBRV), cherry rasp leaf virus (CRLV), tobacco ringspot virus (TRSV), tomato ringspot virus (ToRSV), and Rubus Chinese seed-borne virus (RCSbV or RCSV). ToRSV and TRSV are the most important nematode-borne viruses in North America; RpRSV, TBRV, ArMV, and SLRSV are the most important in Europe (Finn 2008). The main vectors for these viruses are Xiphinema americanum Cobb. in North America and Longidorus elongates de Man and Xiphinema diversicaudatum Micoletsky in Europe (Finn 2008). Plant resistances to the viruses RpRSV, ArMV, and TBRV have been recognized at SCRI (Jennings 1964), and vector resistance to root lesion nematodes Pratylenchus penetrans (Cobb) Fillip and Skek. has been found in the PARC-BC program (Vrain and Daubeny 1986). These viruses are very effectively transmitted by seed; other transmission is either by nematode or unknown. While all of these nepoviruses have been detected in Rubus, and they are in many cases screened for in quarantine, none of them is a serious issue for commercial production of raspberries internationally. 4. Viruslike Diseases. Viruslike diseases include phytoplasmas, such as Rubus stunt, mycoplasmas, and symptoms of severe infestation with mites, such as the leaf and bud mite, Phyllocoptes gracilis (Jones et al. 1988). Rubus stunt is a phytoplasma disease found in Europe, the Russian Federation, and the Middle East. This disease is transferred by leaf hoppers, and it causes symptoms that can be mistaken for a virus. Infected plants produce numerous spindly shoots (witches’ broom) and flower phyllody (abnormal transformation of a floral structures into foliage leaves) and proliferation. Infected plants usually remain symptomless for a year after infection. Heavily infected plants of

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‘Malling Promise’ rarely show the flower proliferation symptoms. ‘Malling Landmark’, in contrast, is a very sensitive indicator of the disease. No work has been done on breeding for resistance, and control is usually by high-health nuclear stock. Treatment is rouging in commercial blocks or by hot water treatment of nursery plants (Ellis et al. 1991). J. Plant Growth Many aspects of plant growth are essential for the production of a high yield of quality raspberries. To look at this in detail, it is pertinent to look at root growth, cane number, cane growth (vigor, growth habit, internode length), spinelessness, bud break, lateral structure, fruit numbers per lateral, yield components, total yield, environmental adaptation, and leaves. Primocane fruiting is also considered as a separate topic as part of the examination of plant growth. 1. Roots. The root system of raspberries is predominantly near the soil surface with major roots spreading out radially from the crown of the plant, although in some deep friable soils, the roots may penetrate a meter or more. The defining characteristics of cultivated red raspberries come from the species R. idaeus and R. strigosus, from which this cultivated crop was initially developed. Crowns are loose and shoots of new canes are subtended primarily from adventitious buds on roots coming from the mother cane, either the first shoot of a seedling or the clone propagated from an initial selection or cultivar. In black raspberries (R. occidentalis) and some other Idaeobatus species, plants very rarely sucker from roots, and the entire plant grows from adventitious buds formed on the crown, although if a cane tip touches the ground it will form roots and a new crown is formed at that point. The crown-forming trait is dominant, and when crossed with red raspberries, the seedlings are all crown forming. In the F2 and later generations, this trait is easily eliminated from a population by selecting for suckering types. F1 hybrids of red and black raspberry may also tip root if the cane tip is pinned to the ground, but as with the crown-forming trait, this trait is lost in subsequent generations of breeding. Interbreeding of F1 black raspberry or species hybrids sometimes produces plants that can be propagated neither by suckers or by tip rooting (Overcash and Wu 1973; Yeager and Meader 1958). Under traditional propagation methods these clones may not be able to be propagated, but the use of tissue culture offers potential for the development of a cultivar that can be tightly controlled by the breeder. Growers would find it more difficult to propagate the new cultivar for

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additional plantings without purchasing plants from the propagator. The crown-forming trait is also of potential value for the development of machine-harvest raspberries, as this could be used to limit the spread of new canes from the crown area and reduce inputs to remove suckers that prevent catcher plates from closing. Red raspberry is adapted to deep, well-drained fertile soils that do not become waterlogged. When they are grown in heavier and wetter soils, growth is restricted and plants become prone to root rots, especially Phytophthora. Several Idaeobatus species are much better adapted to heavier and wetter soils, and some have been used to introgress adaptation and root rot resistance into red raspberries, although there appears to be much more potential for this avenue of approach in further breeding. This would be of particular value in British Columbia and northern Washington to make use of soils that currently cannot grow red raspberries. When raspberries are grown at a location close to their warm-winter temperature limit of adaptation, root bud production and subsequent sucker growth is reduced, resulting in lower numbers of canes and reduced production. In very warm or subtropical climates, most raspberry cultivars will grow for little more than one year before new sucker growth is eliminated and the remaining canes are left in a semidormant state. Roots collected from plants grown in a warmclimate situation have a reduced ability to be propagated; spawn generated from propagation beds planted with roots is considerably reduced in comparison to roots from the same cultivar produced in a cooler climate. For this reason propagation by roots is not practiced as frequently in warm-climate situations as in cool temperate regions, such as the Pacific Northwest of the United States and Canada. 2. Cane Number. There is considerable variability in the tightness of the crown of a red raspberry cultivar as well as in the number of canes produced and their vigor. In wild raspberries from either R. idaeus in Europe or R. strigosus in North America, there are often far too many canes for a commercial cultivar. They may all be vigorous, and only vary in size due to age, or some accessions may have vigorous central canes surrounded by a bed of up to a 100 or more spawn around 15- to 30-cm tall. Suckers can surround the mother plant to a distance of 3 meters or more. When raspberries were domesticated, plants were selected that had tighter crowns, localized spawn production, and a reduced number of canes produced from the crown. Raspberries can be managed and cropped most effectively when cane numbers are limited to 15 to 20 per

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meter or even as low as 6 canes per meter for hedgerow plantings or as few as 8 canes per hill for separated plants of floricane types (Nes et al. 2008). Cane numbers may be as many as 30 per meter of row with primocane-fruiting cultivars. Excess cane numbers are an unnecessary drain on plant resources that could be put into cropping, and they also require investment in management to thin out canes, both during the growing season and during training and pruning of floricane types in the dormant period (Daubeny 1996). The cultivars ‘Sumner’ and ‘Fairview’, both derived from the cultivar ‘Washington’, are examples of cultivars that produce excess canes. This trait is also observed in their seedling progenies. Potentially there are three types of selections that will be of use in commercial production of raspberries: (1) selections with tight crowns with few outlying suckers for production on hills, as in much of the production region in the Pacific Northwest of the United States and Canada; (2) selections with loose crowns for hedgerow production, as practiced in New Zealand; and (3) selections with very loose crowns and widely spaced canes so that each cane has an extended piece of root, for use in long cane production. Another trait of importance for commercial propagation and production of raspberries is flexibility or malleability. Plants that have a brittle attachment point with roots are easily broken off at the joining point with canes. In production of canes for planting, this is important as portions of canes produced cannot be sold and others have reduced quality. In a production field, a brittle attachment point with roots often results in plants or canes being broken off through the action of wind. Progenies that have seedlings with a brittle attachment of roots can often lose numbers of plants because of breakage at the base of the cane. Most often young plants that have been broken off will not regrow. 3. Cane Growth. For an easily managed plant and good productivity, canes need to be of adequate but not excessive numbers; of medium thickness, medium height, and moderate vigor; and have upright growth habit (Daubeny 1996; Ourecky 1975a). Spindly, thin canes have reduced bud break, poor lateral growth, and a higher percentage of vegetative laterals. Thick canes tend also to have reduced bud break, especially in climates where winter chill is marginal or insufficient. Laterals of thick canes are strong and often long, but lateral numbers may also be reduced because internode length is longer and much of the cane may be cut off before being tied down, especially in warm environments with a long growing season, such as Australia, where

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canes can reach 4 to 5 m in length. If canes are bred for medium vigor, short internode length, and medium height, then they are able to produce a high yield without cane vigor control or high inputs during pruning and training, as in ‘Glen Lyon’, a derivative of the compact PARC-BC cultivar ‘Haida’ and of ‘Glen Prosen’. Upright growth habit is a particularly valuable trait, providing the angle of fruit laterals is not too steep. When fruit is ripening, laterals that are led at 65 to 80 from the vertical are ideal. If they hang much below 100 from vertical, they are a problem and the bush can be closed off to air movement. If plants are to be grown in a warm temperate or subtropical environment, upright growth habit is essential as even upright cultivars like ‘Chilliwack’ exhibit sprawling growth when grown in the high-temperature conditions of northern New South Wales in Australia (H.K. Hall, pers. observ.). Even in the cooler location of New Zealand, a less erect cultivar like ‘Malling Leo’ is also affected by the environmental change, having almost prostrate canes under these conditions. If the future of raspberry production is to move to the warmer conditions of Mexico, southern Spain or warm temperate to subtropical conditions in Australia, Africa, and South America, then the growth habit of new cultivars will have to be addressed, with breeding populations evaluated and selected for uprightness under these conditions. In the United Kingdom and Europe, there are major problems with the raspberry cane midge Resseliella theobaldi, which attacks the canes in regions where the epidermis is peeled or damaged (Woodford and Gordon 1979). Cane midge is a vector for the fungal disease cane blight (Leptosphaeria coniothyrium) and other fungi, which can girdle and kill the cane. Even if the cane survives, the midge can often severely limit production. Selection for canes that do not peel their mature primary cortex (the cane bark) or crack during growth is of particular importance as the cane midge lays eggs in these regions, which shelter the midge as it grows and matures. Researchers at SCRI found resistance in R. parviflorus, R. odoratus, and F2 derivatives of R. crataegifolius (McNicol et al. 1983). With the R. crataegifolius derivatives, cracks in the canes were healed through the growth of suberized and lignified cells, and the same tissue growth prevented the peeling of the primary cortex. This tissue growth formed a reticular pattern on canes, which made it easy to identify resistant segregates. At EMR breeders also discovered that R. coreanus was naturally resistant to cane midge (Keep 1984b). Cane strength and the ability of the cane epidermis to handle the passage of catching plates is of particular importance for machine

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harvest of raspberries as this mode of harvest is key for production of processing fruit in developed nations, where cost of labor is high. While canes suffered damage in North America, the absence of cane midge and drier climate during harvest has made this of minor importance in limiting production there. However, in the United Kingdom and Europe, catcher plate damage is more significant, as damaged canes are opened to attack by cane midge and fungal disease. Selection for spineless canes may be counterproductive when reduction of catcher plate damage is desired for machine-harvested cultivars. Spines on cane bases appear to reduce damage by catcher plates, with the spines stopping catcher plates from abrading the canes directly or at least reducing the damage. For spineless cultivars, it is recommended that harvesting machines be used that protect the canes from damage by using spring-loaded trays or a belt to stop catcher plates sliding across the canes. There is considerable variation in the timing of onset of new cane growth across breeding populations. If growth of new canes is late, this is of benefit for both fresh market and process floricane raspberry producers. New canes do not get in the way of production canes, damage to canes is reduced (provided machines do not damage new canes with catcher plates), and hand pickers do not pull canes out into the rows to get access at ripe fruit. When new canes grow outside the floricanes and around the bush, they quickly become a nuisance for picking, either by hand or machine. It is advantageous if the new cane growth is upright and inside the bush, as is found among some germplasm from the SCRI breeding program. 4. Spinelessness. Red raspberries have a range of spines, from small, hairlike bristles to larger, needlelike prickles. Spines may be fine, as in the bristle types above, to coarse and prickly, as in cultivars ‘Heritage’, ‘Kiwigold’, and ‘Marcy’. When these plants are handled with bare hands, tips of spines dig in and break off, making them difficult and unpleasant to work with. Other species from the raspberry subsection of the Rubus genus, the Idaeobatus, have spininess ranging from absent to having large, recurved and very unpleasant spines. When these are used for breeding, spines of the progenies also may be very large and unpleasant, making working with them impossible without protection for hands, arms and the rest of the body. For example, when F1 hybrids were produced between ‘Glen Prosen’ and R. niveus, spines were as unpleasant as a vigorous spiny upright blackberry, over 1-cm long and sometimes recurved, on canes that grew over 2-m tall and around 3-cm thick at the base, similar to canes of spiny, upright blackberry cultivars

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from Arkansas. These large spiny plants pose significant management issues in the field, especially for training and pruning. For further use of interspecific hybrids in breeding, it would be very valuable to have a dominant gene for spinelessness available. Even in cultivars derived from R. idaeus and R. strigosus, spines can become a serious hindrance or obstacle in various cultural operations, making them more difficult and more labor intensive (Daubeny 1996). Spines can also puncture ripening fruits, which causes bleeding and predisposes them to attack by preharvest fruit rot organisms. This can be a serious problem when spiny plants are grown without supports and there is significant wind movement. When winds become strong, fruit are often damaged, even when the plants are well trellised and trained. When canes were left in for more than one season, spiny pieces of cane epidermis were a prominent contaminant of the machineharvested product (H.K. Hall, pers. observ.). Spinelessness in raspberries was first acknowledged in print by John Parkinson in his Paradisi in Sole in 1629 (Jennings 1988) and has long been recognized as desirable for new cultivars as noted by Darrow (1937) that it would be valuable in accessions of R. strigosus. The first practical opportunity arose to breed spineless raspberry cultivars when spinelessness was recognized among the progenies of the old Scottish cultivar ‘Burnetholm’ (Jennings 1962; Lewis 1939). This spineless gene was named gene s, analogous to the similar trait used in blackberry breeding from a spineless selection from the diploid species R. ulmifolius, known as R. rusticanus var. inermis (Crane 1936; Jennings 1986a). Gene s in both blackberries and raspberries is associated with the absence of glandular hairs around the edge of the cotyledonary leaves (Jennings 1988; Lewis 1939; Scott et al. 1957;) (Fig. 32a). Spiny segregates have glandular hairs around the edge of the cotyledonary leaves (Fig. 32b). This trait was introgressed very quickly into the SCRI breeding program, resulting in the release of the first spineless cultivars ‘Glen Moy’ and ‘Glen Prosen’ in 1981 (Jennings 1982b,c, 1983a, 1995; Royle 1985). By the mid-1980s the spineless trait had been bred into almost the entire SCRI breeding program, and the only spiny plants observed were among seedling populations of F1 hybrids grown out from crosses with spiny cultivars (H.K. Hall, pers. observ.). In subsequent generations, crosses were done to enable selection for gene s homozygotes, and spiny segregates were discarded as small seedlings. Crosses between spineless homozygotes are all spineless. Gene s is very stable, and no problems have been experienced with reversion to spininess in raspberries. Commonly the first true leaves of raspberries may have spines on the edge of leaf petioles, but mature leaves and

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Fig. 32. Rubus seedlings with (A) spineless (ss) and (B) spiny (S-) cotyledons. (photo H.K. Hall).

canes are entirely spineless. In blackberry this gene also is very stable, and in spite of large populations only a very few sectoral reversions have been observed where a few spines have been seen (Clark et al. 2007). Breeding for raspberry improvement was active in England (EMR), Oregon (ORUS), Washington (WSU), and British Columbia (PARC-BC) since the 1950s and early 1960s, but in recent years little work has continued in Oregon. Spineless selections and spiny heterozygotes bearing gene s from SCRI were widely utilized in these programs. When the New Zealand and Australian raspberry breeding programs were initiated in the 1970s, selections from SCRI and North America were used to begin these southern hemisphere breeding programs. In New Zealand it was found that ‘Chilliwack’, ‘Comox’, BC 74-11-41 (later released as ‘Clutha’), ‘Glen Clova’, ‘Malling Delight’, and ‘Skeena’ contained the recessive gene s. Breeding populations segregating for this trait were produced in the early 1980s. The cultivars just listed were crossed widely with spiny types, and

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selections from these populations were progeny-tested to see which ones contained gene s. Further spineless germplasm was collected as open-pollinated seed from SCRI in 1985 and received in New Zealand as crosses from SCRI in 1986. Selections from SCRI material were incorporated in the New Zealand breeding program in the late 1980s. In the 1990s, breeding parents were selected from among spineless elites or heterozygotes, and crosses were done to introgress spinelessness into the New Zealand raspberry breeding program. Seedling progenies were screened for spinelessness, and by 1995, field-grown seedling progenies were largely spineless, as in the SCRI breeding program (Hall 1992; Hall and Brewer 1993; Hall and Daubeny 1999). In the Australian, PARC-BC, EMR, and WSU programs, selections from SCRI were also used in breeding. Since the year 2000, genetically spineless cultivars have been released from both the EMR and PARC-BC programs. However, none of these programs has placed the continuing emphasis on breeding for spinelessness that was placed on the SCRI program by Derek Jennings or the New Zealand program by Harvey Hall. Many of the selections and cultivars from the Australian, PARC-BC, EMR, and WSU programs were spiny homozygotes or heterozygotes. At SCRI and in New Zealand, the emphasis placed on breeding raspberries for spinelessness using the recessive gene s from ‘Burnetholm’ has produced some excellent spineless selections and cultivars. However, selection for this trait has restricted breeding progress in other areas, particularly when another trait important for production or quality has been considered. Breeding progress is always reduced when it is required to sib or backcross to retain a recessive trait, such as gene s spinelessness. As gene s in raspberry is analogous to gene s in blackberry, it is useful compare the use of genes for recessive spinelessness in the two crops. In blackberry, the effect of using gene s for breeding has been very significant. New cultivars have been released with complete absence of spines and a dramatic improvement in the ability of plants to be handled, especially for pruning and training. Nevertheless, use of this source of thornlessness resulted in considerable reduction in breeding progress in developing new blackberry cultivars (Clark et al. 2007) from what would have been possible if a useful dominant gene had been used. Effects of using recessive genes in breeding for spinelessness in blackberries and raspberries include the following: 1. In blackberries, growing of spiny F1s has been expensive as well as unpleasant to field workers pruning and training the seedlings.

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Plants have to be widely spaced, and because of their spininess all pruning and training operations take longer than with spineless selections. In addition, it is more difficult to get labor to do this work. Difficulty in training and pruning is also significant in raspberry breeding when wild Idaeobatus species have been used for breeding, especially those with very spiny canes, such as R. niveus or R. occidentalis. Raspberry F1 interspecific hybrids may be as big and as spiny as F1 hybrids between spiny and spineless blackberries. 2. Grower and marketer demand for spineless cultivars restricts the value of selections from F1 hybrids within blackberry and with interspecific raspberry populations, especially with some Asiatic species, as they are very spiny and not suitable for commercial release. In crosses between spiny and spineless red raspberries, the spiny F1s may be usable for commercial release except for the very spiny segregates. 3. Maximum progress in breeding can be obtained in Rubus by outcrossing, bringing together the most diverse genetics to produce a high level of heterozygosity in progenies. In contrast, using the recessive gene s requires inbreeding for the gene to be expressed, bringing some degree of inbreeding depression. Inbreeding is particularly significant when genes for economic traits or for adaptation are closely linked with genes at the same locus as gene s. In blackberry, trailing growth habit, lateness, acidic fruit quality, and lack of cold-hardiness were closely linked to gene s. 4. In blackberry, the tetraploid genetic constitution has further restricted progress significantly due to the extra costs of crossing and growing seedlings in order to obtain enough spineless segregates for planting in the field. In blackberry, where segregation ratios are 1:15 for backcross populations and 1:35 for sib crosses among F1 seedlings, compared to 1:1 and 1:3 in diploid raspberries. In raspberries the requirement to produce large numbers of seed and seedlings is reduced but it remains that more effort needs to be invested than if spinelessness was dominant. In both blackberries and raspberries, F2 seedlings resulting from a back cross to spiny types need to be progeny tested to determine whether they can hand on spinelessness. For example in 1978, 216 seedling populations were grown at EMR, 180 of which (over 83%) were open pollinated seed lots of clones being evaluated for the presence of gene s (Keep et al. 1979).

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5. Use of gene s recessive spinelessness in raspberries restricts breeding progress much less than in blackberries, due to the raspberry diploid chromosome compliment. Use of gene s from ‘Burnetholm’ also favored breeding success as it is linked with many other good traits, including immunity to raspberry ringspot and Arabis mosaic viruses, hairy canes and escape from cane fungal diseases, good growth habit, and superior fruit size, flavor, firmness, color, and appearance (Jennings 1963b). Because of the advantages of growing only spineless seedlings in the field, several dominant genes for spinelessness in raspberries have been investigated. One selection, PSW (Peter Serpell’s Willamette), a spineless mutant of ‘Willamette’, was discovered in Australia (Jennings and Brydon 1990). Seedlings from open-pollinated seed of ‘Willamette’ produced only spiny segregates, whereas OP PSW segregated for eglandular cotyledons, similar to derivatives of ‘Burnetholm’, with eglandular segregates growing into spineless adult plants. Crosses between ‘PSW’ and ‘Willamette’ and two wild raspberries produced only spiny offspring, regardless of which parent was used as male or female. In other crosses with the SS parents ‘Meeker’ ‘Latham,’ and ‘Leo,’ a small proportion of spineless seedlings were produced but with ‘Meeker’, this occurred only in one year’s crossing in one direction. No spineless segregates were produced in a cross with ‘Tayberry’. In crosses done with the ss parents, all seedlings were spineless; in crosses with Ss types, the progenies segregated for spiny and spineless. The behavior of this gene, designated Sfw by Jennings, is undoubtedly dominant in some circumstances but not in others, so the prospect of using gene Sfw for breeding is limited in its usefulness (Jennings and Brydon 1990). When PSW was imported to New Zealand, it was propagated by a root sucker and the spineless character disappeared, showing that the plant was not uniform genetically, being genetically spineless in only part of the L2 and L3 tissues. This may be a reason for unexplained segregations and different results in different years. Other prospective dominant genes for spinelessness have been identified in raspberry cultivars ‘Framilo’, a mutant from the cultivar ‘Multiraspa’ (Jennings 1993), and ‘Framita’, a spineless mutant of ‘Zefa II’ (Daubeny 1997a). Jennings (1993) has investigated the inheritance of spinelessness from ‘Framilo’ and found that inheritance was dominant, but these sources of spinelessness have not found a place in raspberry breeding.

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In New Zealand, an attempt was made to transfer the dominant spineless gene SfL from ‘Loganberry’ to raspberry (Hall and Stephens 1999a). Successful transfer of the ‘Loganberry’ gene was possible into a 4 hybrid by crossing with red raspberries; the backcross to raspberry was successful, giving presumed triploid spineless hybrids. Subsequent backcross attempts to red raspberry were successful, but all seedlings from these crosses were spiny. Further attempts were also made to obtain dominant spinelessness for red raspberry breeding involved using spineless plants of R. odoratus (Jennings and Ingram 1983). Seedlings derived from red raspberry crossed with R. odoratus were all spineless in the F1 generation, but in the F2 and further generations, the trait displayed continuous variability from nearly spineless to very spiny (Jennings and Ingram 1983). This trait is not a single gene and was not useful for further breeding as the dominant trait could not be recovered in further generations. 5. Bud Break. When cane numbers are optimal, growth is adequate, growth habit is upright, and canes are healthy, the next important factor toward production of an economic yield is bud break. If buds are close together, there is increased potential for a high yield when they break at the appropriate time and grow to produce fruit. Factors controlling bud break in floricane-fruiting raspberries include flower initiation, cane diameter, cane growth, openness to light, adequate winter chill, sufficient warmth, and absence of pest or disease attack. Flower initiation occurs when cane growth has reached the stage of physical maturity for initiation to occur. In floricane-fruiting types, buds in which flower initiation has occurred remain dormant until after a period of chilling has given sufficient vernalization for growth to commence. When the chill requirement is satisfied, the onset of a warm period results in bud break and growth. Normally this occurs in springtime, but if the chill requirement is satisfied early in winter, then any period of warm weather will result in bud break. If this happens to be before winter has ended, then there may be severe damage to buds with the return to cooler temperatures. Chill requirement in raspberries is met by the acquisition of chilling hours below 12 C or likely below 8 C (Dale et al. 2003). Peak chilling accumulation rate is estimated at being around 4 C, or even as high as 6 to 7.5 C (Rodriguez and Avitia 1989), dropping off again until below 0 to 2 C, when the chill accumulation rate again approaches zero. As an approach is made toward the poles from the equator, or as

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movement is made to higher altitude, chill accumulation begins and at a certain point it peaks; moving to increasingly cold locations, it drops again toward zero. The highest chill appears to be required for cultivars developed in Oregon on the U.S. West Coast, and around New Jersey on the U.S. East Coast. These have the poorest adaptation to the low-chill conditions of Australia and New Zealand. At locations south and north of the high-chill sites, apparent chill requirement is lower, with the result that cultivars from California and British Columbia or New York and North Carolina are better adapted to a warm location like New Zealand than others developed between these locations (H.K. Hall, pers. observ.). Similarly, cultivars produced at SCRI appear to require less chilling in Australia and New Zealand than floricane cultivars produced at EMR. In Finland, the cold-hardy cultivar ‘Ottawa’, which is grown across northern Europe, was assessed to have a chilling requirement of 960 hr, whereas ‘Glen Ample’, from a more southerly latitude in Scotland, required at least 1200 hr (Palonen et al. 2008). In contrast, the locations where plants are most likely to encounter warm-temperature spells during winter are in Oregon on the west coast of the United States and in the southern Pennsylvania–New Jersey– North Carolina region and southward on the East Coast (Swartz et al. 1992). To escape the effects of these warm-weather periods, an adapted cultivar needs to have a higher chill requirement and deeper dormancy during winter. Effects of lack of winter chill in raspberries include delayed growth of buds, sporadic bud development or complete bud failure, lateral growth only at cane tips, failure of mid-cane buds to grow, and short, chlorotic laterals (Fear and Meyer 1993). Further effects include growth of vegetative laterals and extended time for laterals to flower (Jennings, pers. comm.). Selection for low-chill requirement produces rapid results when transgressive segregants from high-chill  high-chill crosses are chosen and recurrent mass selection procedures are used (Fear and Meyer 1993). In the second cycle of recurrent selection from this sort of program in Mexico, selections were chosen with chilling requirements in the range of 150 to 500 chill units (Rodriguez and Avitia 1989). Progress in developing low chill adaptation can be even more rapid when using low-chill tropical or subtropical Rubus species but fruit quality is more difficult to attain (Drain 1939; Overcash 1972). In New Zealand, a range of seed lots of open-pollinated RBDV-resistant selections and cultivars from SCRI were imported in the mid-1980s and the seedlings were grown in the field. A few populations were completely devoid of growth after the first winter, but from the majority

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of seed lines there were some plants that had good bud break in New Zealand conditions. One of these selections, B257, was crossed with F29, an RBDV-susceptible selection from the cross ‘Marcy’  ‘Malling Delight’, to give the RBDV-resistant machine-harvestable selection ‘Motueka’. Another selection, D188, was crossed with Moutere (Plate 4B), and this cross yielded the most selections with promise from any cross in the HRNZ program: 17 advanced selections from a population of 170 seedlings. One of these selections has been released as the early-fruiting cultivar ‘Korere’ (Plate 4D), several others remain under trial. None of these 17 selections has at any time tested positive for RBDV, and they have provided a parental base for a step ahead in quality, growth, and productivity for further breeding (Fig. 33). Other early-fruiting releases from the HRNZ program include ‘Awaroa’ (Plate 4G) and ‘Okawa’. Bud break for flowering in cane tips of primocane-fruiting types is independent of chill requirement, but it remains dependent on the canes achieving physiological maturity for flower initiation followed by bud development, flowering, and fruiting before entering dormancy. Nevertheless, a requirement for dormancy and/or chill is still retained by most primocane-fruiting cultivars, with bud break, flowering, and fruiting only occurring partway down the cane, even when grown in continuous warm conditions. This is similar to floricane-fruiting cultivars, which usually only break bud down to about 10 nodes above the ground in full-size canes. In subtropical to tropical conditions, most primocane-fruiting cultivars become quiescent after 3 years or less, and they can be coaxed into growing again only by artificial or natural chilling. ‘Summit’ raspberry is one of the few primocane-fruiting cultivars that continue to cycle, growing new canes and fruiting over and over in a low-chill environment without entering a quiescent state (J. Lopez-Medina pers. comm.). Many floricane-fruiting cultivars have a small portion of buds at the primocane tips on the most mature canes that achieve the physiological state for flowering to occur and fruit to ripen, especially in a warm climate with a long growing season. From this sort of material the first double-cropping and primocane-fruiting cultivars were selected. Further breeding of primocane-fruiting types has resulted in selection of transgressive segregants exhibiting earlier achievement of physiological maturity for flower initiation as well as more effective removal of dormancy of initiated flower buds. In addition, earlier maturity has been introgressed from R. arcticus and R. spectabilis, and from earliestflowering floricane-fruiting selections and cultivars (Keep 1984a; Knight 1991).

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Fig. 33. Fruit of D 188, an open-pollinated seedling from SCRI 7331/1 Rev, a reverted gene L1 selection (A); fruit of ‘Moutere’ (B); and fruit of 10 selections from the cross D188 ‘Moutere’ (C).

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6. Lateral Structure. In different programs, raspberry cultivars have been bred with considerably different lateral structure, in accordance with environment, breeding aims, and local production and industry concerns. The major determining factor for lateral growth, diameter, length, fruit number per lateral, and number of fruiting nodes per lateral is genetic, associated with the cultivar. However, laterals are also highly responsive to environmental factors, especially winter chill, with lack of chill inducing sporadic bud break, short lateral length, sometimes vegetative laterals, and sometimes very long late laterals as with ‘Glen Lyon’ grown in southern Spain and Portugal (D.L. Jennings, pers. comm.). Thin cane growth reduces lateral thickness and may result in lack of bud break or vegetative laterals, whereas very thick cane growth results in thick laterals and in a low-chill environment a noticeable reduction in bud break. Raspberries vary considerably in lateral angle, with some being almost upright and others hanging down so that foliage is densely compacted around the plant. Very steeply ascending laterals are suitable for hand harvest, unless combined with very strong vigor when top fruit may be out of reach of pickers. If primocanes are pruned low when they are trained, this may correct the problem, but lateral attachment needs to be very strong to eliminate lateral breakdown during harvest. Cultivars with upright or nearly upright laterals are also prone to bird damage with the fruit presented for birds to eat. This can be a significant issue in Australia, where large parrots come in flocks to browse foliage and fruit. Steeply ascending laterals are also suitable for machine harvest if harvested by a horizontal shake machine. If attempts are made to harvest fruit with a vertical shake machine, much of the crop can be left on the plant, especially if the cultivar requires a significant removal force to dislodge fruit from the plant, as in ‘Skeena’. Some cultivars have ascending laterals during early growth and flowering, but when the fruit ripens the laterals hang outward and lower down. Lateral presentation on these cultivars is well suited for both hand and machine harvest providing the lateral angle does not increase beyond 100 . Lateral strength and lateral attachment is important for reliable production of a cultivar, and some cultivars and selections have been particularly prone to lateral breakdown. In New Zealand, the cross ‘Malling Exploit’  ‘Lloyd George’ was particularly prone to lateral breakdown, as were seedling populations that involved ‘WSU 608’ as a breeding parent. ‘Skeena’ on the other hand passed on strong laterals and strong lateral attachment to its offspring ‘Centennial’, ‘Chilliwack’, ‘Clutha’, and ‘Comox’. M82 (‘Skeena’  ‘Marcy’), 84-5C47 (‘Sumner’ 

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‘Skeena’), and 8492P2 (‘Skeena  Haida’) from the New Zealand program also showed strong laterals and good lateral attachment. This trait is inherited in many of the progenies in the F2 and is also seen in ‘Qualicum’ (‘Glen Moy’  ‘Chilliwack’), ‘Kitsilano’ (‘Comox’  EM 3909/4), ‘Esquimalt’ (‘Comox’  ‘Glen Ample’), and ‘Bogong’ (‘Comox’  ‘Autumn Bliss’). In ‘Bogong’, as in other primocane-fruiting ‘Comox’ derivatives, laterals are long and strong and the strong lateral trait comes through very well for primocane fruiting, giving high productivity. In New Zealand, ‘Skeena’ derivatives have combined well with derivatives of R. occidentalis and R. pileatus to give extremely strong and well-attached laterals to the fourth generation removed from ‘Skeena’. The most outstanding of these had strong, well-developed laterals that remained on the canes until pruning out and canes were mulched. At SCRI, selection was for short lateral cultivars with around 10 to 15 fruits per lateral (D.L. Jennings, pers. comm.). Shorter lateral length promotes earlier production and shorter fruiting season, a distinct advantage for cultivars producing in the short Scottish growing season (Dale and Topham 1980; Jennings, pers. comm.). In contrast, selection for lateness and productivity at EMR led to the development of cultivars with very long laterals, high fruit numbers per lateral, and an extended late harvest season. Use of Asiatic species in breeding red raspberries has also made possible the selection of late-fruiting types with shorter laterals and moderate fruit numbers per lateral. Segregants from introgressing R. pileatus into red raspberry germplasm also gave extremely long laterals, up to 2 m in length on some seedlings. 7. Fruit Numbers per Lateral/Fruiting Node. In R. idaeus and R. strigosus, fruit numbers per lateral are usually less than 30 and frequently only 10 to 15 and often only 1 to 3 fruit per node on the fruiting lateral. Most cultivars derived from R. idaeus and R. strigosus have low fruit numbers per lateral. For example, the old EMR cultivar ‘Malling Jewel’ had only 9 to 12 fruits per lateral (Keep et al. 1980a), similar to the SCRI Cultivar ‘Glen Clova’. Breeding efforts at EMR have focused on improving yield by increasing fruit numbers per lateral, using genetics from R. cockburnianus, R. coreanus, R. flosculosus, and R. occidentalis (Keep et al. 1980a, 1982; Knight 1986). ‘Malling Leo’ was the first release from breeding using R. occidentalis, followed by ‘Malling Joy’. Both cultivars are late, have very long fruiting laterals, and high yields have been achieved, especially with ‘Malling Joy’, which achieved over 20t/ha in a trial at SCRI (Keep et al. 1981).

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Derivatives of R. cockburnianus have been selected with fruit numbers of 25 to 65 per lateral. R. flosculosus, which has up to 180 fruits per lateral, was used in an effort to develop clones with even higher fruit numbers per lateral (Knight 1986). Development of late-fruiting, longlateral cultivars has both increased production and extended the harvest season. Extended harvested season is particularly valuable for freshmarket production. However, for processing, it is not desirable to extend the harvest season, especially if this is achieved by increasing lateral length, as cultivars with longer laterals are more difficult to harvest by machine. R. flosculosus offers promise of increasing production with more fruit per lateral without increasing the harvest season as the ripening is reasonably condensed (Knight 1986). One consequence of selecting for long fruiting laterals has been the extension of internodes on fruiting canes and increase of cane length, both found with ‘Malling Leo’ and ‘Malling Joy’. When these cultivars are grown in warmer climates, they have excessively long canes and very long cane internodes. Another approach to increase yield through increased fruit numbers per node used at SCRI and at EMR has been to select for clones with multiple laterals per node (Knight 1986). At SCRI, this trait was not pursued further as it did not appear reliably in all canes, and it also appeared to limit the ability of the plant to survive the effects of debilitating late-spring frosts (Jennings 1979). In addition, the SCRI investigations indicated that double laterals on smaller-diameter canes did not result in higher yields because of compensation and other factors resulting in little increase in yield in selections with a higher proportion of double laterals (Jennings 1979). At EMR, selections with double lateral formation were identified and incorporated in the breeding program, but thus far no cultivars have been released with enhanced yields due to double lateral formation (H.K. Hall, pers. observ.; Knight 1986). Frequently with long or even with short laterals, the flowers farther down the lateral abort and do not develop to produce fruit. This can be reduced by a very effective watering and nutrition regime, especially using trickle irrigation and fertigation. Fruit development is especially promoted, and each flower bud may develop through to a ripe fruit when the season is long enough and when new cane growth is removed, as in Californian production methods. 8. Yield Components. Plant number, cane number per crown or per meter of row, row spacing, vigor, lateral number, fruits per lateral, and fruit size together determine the yield of a raspberry cultivar (Dale 1989).

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Some of these components are determined by cultural methods and practical management factors, which vary according to the purpose of growing the crop, the planned market, and the desired hand and machine inputs. When a crop is grown outdoors, cultivated by tractor, and harvested by machine, a row spacing of 2.6 to 3 m and plant height of up to 2.2 m is usually chosen, depending on the machinery used and the space required for the chosen cultivar. This is significantly wider row spacing required than when cultivation is by hand or with the use of walk-behind machines or draft animals, when row spacing can be reduced to 1.8 m or even as close as 0.9 m (Dale 1989). Spacing within the row can be as close as 0.5 m between hills or in a hedgerow up to 30 or 40 canes per m. As distance between rows and plants or canes is reduced, production per cane or plant is reduced, but it is more than compensated for by the increased production per unit area (Dale 1989). With floricane-fruiting cultivars, the optimum cane density is around 5 to 8 canes per m2 (Dale 1989). With primocane-fruiting raspberries, cultivars with the highest yield index should produce highest yields at a similar cane density. However, lower-yielding primocane-fruiting or dual-cropping cultivars benefit from significantly greater cane densities up to 30 to 40 per m of row, especially when most of the crop is produced on cane tips, as with ‘Southland’ or ‘Marcy’. Row, plant, and cane spacing are ultimately governed by the availability of land, the practicalities and cost of cultivation, fertilization, control of pests and disease, and harvest as well as the monetary return for the crop. Solutions suitable for industrialized nations with high cost of labor, a plentiful supply of high-quality land, and access to expensive machinery for cultivation and harvest are quite different from production regions in poorer nations with an abundance of cheap labor, limited cultivable land, and limited access to funds or expensive equipment. When plants are grown under glass or in tunnels, row spacing is usually much closer than in the open field situation as efforts are made to maximize yield per unit area rather than make large-scale production as easy to manage as possible. As in the outdoor situation, the optimum spacing is affected by the cultivar chosen and particularly the lateral length. For tunnel production, ‘Tulameen’, due to its longer lateral length, requires significantly more space than cultivars such as ‘Glen Ample’ or ‘Chilliwack’. When examining the range of factors considered in production of raspberries, it is clear that a number of approaches can be used to achieve the best desired plant structure and balance of yield components. A different approach is appropriate for each specialized

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production and management growing system and intended end use. For example, with machine-harvested process raspberries grown in large-scale farms, increased yield harvested per machine can be achieved by developing two or more cultivars that can be picked sequentially with early and later harvest windows. For efficient use of a harvester, machine-harvest cultivars need to have a short production season with a high percentage of the crop being recovered at each pass of the machine. 9. Total Yield. In traditional growing regions, raspberry yields vary considerably from block to block, cultivar to cultivar, and region to region. Cultivars able to produce the highest yield for a region have performance capability imparted to the plant through their genetic background in addition to being planted on good soil, managed well, adapted to that location, and protected from pests and disease (Dale 1986). While the cultivar is critical to outstanding yield performance, much is lost commercially through poor choice of land, ineffective shelter, lack of weed control, poor training and pruning, inappropriate fertilizer regime, poor water balance, and lack of control of pests and disease. In New Zealand, research trials produced approximately double the yield of the same cultivar in grower fields. However, elite growers in California and Washington State produce commercial yields that equal or surpass trial plots due to excellent commercial management practices. Consequently growers can take advantage of superior new cultivars and deliver production close to their genetic potential. Floricane cultivars grown in a perennial production system produce yields that are limited by compensatory factors within the plant. Part of the plant’s growth and resources is directed into producing new canes for carrying the subsequent year’s crop. When new canes are removed throughout the growing season, yields are significantly higher, so that in a biennial production system, yields of a single crop are up to 1.8 times the normal annual crop. In some regions, this system has been trialed as the commercial practice. It shows potential for adoption when costs of labor are high, not requiring hand pruning to remove old canes. When raspberries are grown in warm temperate regions, the first floricane crop has significantly better bud break than in subsequent harvest seasons. With higher-chill cultivars, they may have a moderate bud break during the first harvest season, and thereafter the crop is reduced and may be uneconomic. In New Zealand and Australia, this has meant that cultivars like ‘Meeker’ and ‘Glen Ample’ are unproductive and ‘Nootka’, ‘Tulameen’, ‘Chilcotin’, and ‘Fairview’ can be grown

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only in locations with cooler winters and higher winter chill, unless supplementary chill is given. In California, the propensity of plants to yield more when new primocanes are removed and the tendency to have greater bud break for the first year’s fruiting are utilized in the ‘‘Two Crop’’ production system used by DSA, in combination with primocane fruiting on cane tips in the summer/autumn after planting. With primocane fruiting and dual-cropping cultivars, the primocane crop is also enhanced in the first production season and drops off in subsequent years. Thus in this system, three yield-enhancing traits of raspberries are brought together in one production system. Plants are propagated and set in the field in winter, fruited some 6 months later on primocanes and then again on floricanes the following spring, when all new canes are removed. Plants are then removed and subsequent crops are harvested from new plantings. Yields of over 50t/ha are achieved commercially from the two crops. Advantages of the ‘‘Two Crop’’ system are: (1) enhanced yield and quality, (2) reduction of problems from perennial weeds, (3) reduction in problems with viruses and other diseases, (4) ability to use cultivars that cannot produce continually in perennial culture in that environment, (5) effective control of the genetics of the cultivars, and (6) ability to move quickly to new cultivars when better ones are developed. To make the ‘‘Two Crop’’ system successful, it is important to have a nursery with a high standard of propagation excellence, good-quality control, and systems to ensure trueness to type producing sufficient high-quality plants economically. The ‘‘Two Crop’’ system works very well on fumigated ground and requires expert management, agronomy, fertilizer and water control, and quality control for a dependable supply of fruit to flow to the market. The ‘‘Two Crop’’ production system fits well with the use of tunnels to protect the crop from adverse weather conditions and enables manipulation of the harvest season and assurance of quality for the fresh market. In southern California, climatic conditions are too warm for floricane production as even in the first season bud break is limiting. In those conditions, production is restricted to primocane-fruiting cultivars and no crop is taken from the floricanes. Primocane cultivars for southern Californian conditions are selected to crop as far down the cane as possible, rather than only on the top half, as in the production region on the central Californian coast where most Californian raspberries are grown. In Australia and Europe, the tendency of first-season floricanes to have good bud break and produce a high yield without competition of

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new canes is utilized in the ‘‘Long Cane’’ production method. Canes up to 1.8 to 2 m long are produced in a nursery, dug, wrapped and coldstored (0.5 C to 1 C), and then planted out at a time to bring production for a desired time slot. All new cane growth is removed until harvest has been completed. In the southern production regions of Spain and Portugal, production is entirely out of season. Farther north, production is targeted to be early, perhaps the normal season, or later, during the primocane production season. This system has allowed high-quality fruit from ‘Chilliwack’ (Australia), ‘Glen Ample’, ‘Glen Lyon’ (Europe), and ‘Tulameen’ (both Australia and Europe) to be available throughout the year. Canes can be stored for use in long cane production for up to 1 year in ideal storage conditions, but canes stored for a longer period may have reduced yield when planted and cropped (Heiberg et. al, 2008). Canes may also be dug before chilling has been completed in the field and further chilling given in a cool-store to increase bud break (Camposano et al. 2008). Floricane yields in perennial production achieved in research plots at the PARC-BC, WSU, and ORUS programs have varied considerably, especially at WSU, where trials have been carried out in soils heavily infested with Phytophthora, which kills susceptible clones. Highest yields have been achieved with ‘Qualicum’ (Plate 5G) in British Columbia (26 t/ha) (Kempler et al. 2005b) and with ‘Cascade Bounty’ at Puyallup, Washington (34 t/ha) (P.P. Moore 2007). At Mt. Vernon, Washington, under outstanding management, yields of a single floricane crop reached 47.2 t/ha with ‘Glen Ample’, 44.3 t/ha with ‘Qualicum’, 39.9 t/ha with ‘Chilcotin’, 39.7 t/ha with ‘Lewis’, 39.4 t/ha with ‘Comox’, and 36.6 t/ha with ‘Tulameen’, compared with the standards ‘Meeker’ (28.2 t/ha) and ‘Willamette’ (28.2 t/ha) (Finn et al. 2001b). In California, an exceptional selection was measured in a plot yield as equivalent to over 100 t/ha (H.K. Hall, pers. observ.). In New Zealand, plot yields achieved by selections reached 39 t/ha for a single floricane crop and as high as 53 t/ha for the combined yield of a single primocane crop followed by a single floricane crop without removal of new floricanes (H.K. Hall, pers. observ.). In New York State, floricane yields in perennial production have approached 20 t/ha in ‘Titan’ and other productive genotypes (C. Weber, pers. observ.) Clearly there is a lot of scope both in cultivar improvement and in the horticultural management of raspberries to achieve improved yields. Each yield component needs to be enhanced to extend production further to increase economic returns for a high-quality raspberry crop, both for fresh and process cultivars. Breeders should continually strive

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to elicit more of the potential available among raspberries for increasing production. With an elite cultivar, a management protocol needs to be tailored for specific local growing conditions to produce the highest yields. 10. Leaves. Red raspberry leaves are pinnate, usually with 5 leaflets on primocane leaves and 3 leaflets on floricane laterals, although the fruiting laterals of some cultivars have 5 leaflets or sometimes a transitional form between 3 and 5 leaflets where the terminal leaflet has 3 lobes (Leemans and Nannenga 1957). Leaf growth in raspberries has a number of significant effects on plant performance. An increase in leaf area may give rise to increased photosynthesis and improved ability for the plant to produce sugars and convert that to growth. However, no indication is available that raspberries are nearing their biological potential; indeed some selections have been measured with yields of over twice the current commercial yields of the best cultivars (H.K. Hall, pers. observ.). Leafier plants have potential to shade the fruit and protect it from sun in high-temperature conditions, reducing sunburn and sun scald (Renquist et al. 1987). However, for hand-harvested crops, leafiness is a significant impediment for harvesting as it reduces picking speed and results in a higher percentage of fruit being missed by pickers and remaining on the plant to contaminate later picks and provide a source of inoculum of fruit rot organisms. For machine-harvested crops leafiness does not restrict harvest, and on some cultivars it may enhance fruit removal as it provides increased contact surface with the plant. Increased leafiness of plants has further impact on raspberry production, especially in areas with rainfall during the harvest season and where penetration of sprays is essential to growth and production of a commercial crop. A leafy raspberry cultivar restricts penetration of sprays, which makes good coverage difficult to achieve and slows down drying and air movement through the plant. The result is an increase in fruit rots as well as cane and leaf diseases and a reduction in the commercial value of the crop. Problems with fruit rots in leafy plants are compounded if rainfall is frequent and humidity is high during the fruiting season. For development of raspberry cultivars for temperate growing conditions where rainfall usually occurs during harvest, or where spraying is essential to control pests or disease, it is recommended that leafier selections be overlooked in preference for selections that have smaller leaves with narrow, nonoverlapping leaflets on stalklets, rather than broad leaflets that are sessile and overlapped (Leemans and Nannenga 1957).

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‘Meeker’ is a cultivar with an open bush with reduced leafiness, where air movement is free and spray penetration is excellent. This open structure also makes the plant less susceptible to spring frosts, as even a small amount of air movement can reduce frost damage. 11. Primocane Fruiting. In most cultivated red raspberries, axillary buds of first-year canes remain dormant until the second year and then produce lateral branches, producing the characteristic floricane- or summer-fruiting crop. In primocane-fruiting types, flowers and fruit are produced basipetally, from the cane tips toward the base after the cane reaches the right stage of physiological maturity during the growing season, leaving only the lower part of the cane to fruit in the normal floricane season. This behavior is uncommon among raspberries but is characteristic of species such as R. arcticus, R. illecebrosus, R. odoratus, and R. saxatalis (Jennings 1988). In wild raspberries, the primocane-fruiting trait was found in 5 seedling progenies out of 20 seed lots from Britain. It is also found among wild raspberries in Siberia, both R. idaeus and R. melanolasius, possibly allowing the plants to fruit in that severe northern environment (Haskell 1960b; Jennings 1988; Kuminov 1956). Recent evaluations of wild R. strigosus and R. occidentalis populations from North America have observed primocane fruiting as well (C. Weber, pers. observ.). Primocane-fruiting raspberries have been known and cultivated in Europe and North America for over 225 years (Mawe and Abercrombie 1778; McMahon 1806). These types fruit on current year’s primocanes and have variously been known as ‘‘everbearing,’’ ‘‘autumn fruiting,’’ ‘‘fall bearing,’’ or ‘‘primocane fruiting’’ (Darrow 1937; Keep 1988). As this fruiting character was found on the tips of primocanes and not necessarily in the autumn or fall, the term ‘‘primocane fruiting’’ as proposed by Lawrence (1981) has been accepted as the name for this type of fruiting. Subsequent development of new cultivars has vindicated this decision as new cultivars have been developed that produce earlier and earlier fruit. For example, primocane fruiting on the cultivar ‘Augustred’ has been observed to begin on December 2 in New Zealand, over 3 weeks earlier than the onset of fruiting with the late-fruiting floricane-fruiting cultivar ‘Tadmor’ (Plate 4H). In the Small Fruits of New York, Hedrick (1925) described 65 red, purple, and black American and European primocane-fruiting cultivars. Most were chance seedlings with low yields of poor-quality fruit starting to ripen on unbranched cane tips in September or October (northern hemisphere). Many of the early primocane-fruiting cultivars were triploid or tetraploid, but this was neither associated with the trait nor

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an adaptive advantage for primocane fruiting (Jennings 1988). Triploid cultivars included ‘Erskine Park’, ‘All Summer’, and ‘White Queen’; tetraploids included ‘Fontenay aux Roses’, ‘Belle de Fontenay’ (‘Belle d’Orleans’), ‘Perpetuelle de Billiard’, ‘Merveille de Quatre Saisons’ (‘Merveille Rouge’), ‘Souvenir de Desire Bruneau’, ‘Surpasse’, ‘Merveille Blanc’, ‘Colossus’, and ‘Surprise d’Automne’ from France; ‘Hailsham’ and ‘November Abundance’ from England; and ‘La France’ selected in Connecticut of the United States (Jennings 1988; Slate 1940). In 1934, intensive efforts were started at Cornell University (Geneva, New York State) toward the development of primocane-fruiting raspberry cultivars (Ourecky 1978). Germplasm used in this effort was the diploid varieties ‘Lloyd George’ from England, ‘Ranere’ (‘St Regis’), pure R. strigosus from New Jersey (Swank 1913), and wild R. strigosus selections (Slate and Watson 1964). The first cultivars from this program were ‘Taylor’ (1935), ‘Indian Summer’ (1936), and ‘Marcy’ (1936) (NYSAES 1986), although only ‘Indian Summer’ was released as a primocane-fruiting cultivar and all received their primocane-fruiting ability only from ‘Lloyd George’. Subsequent breeding led to the selection and release of ‘September’ in 1947 from the cross ‘Marcy’  ‘Ranere’ (Slate 1954). Further breeding at CU-NYSAES using ‘Lloyd George’ derivatives continued through the 1950s and 1960s, resulting in the release of ‘Heritage’ in 1969 from the cross NY 463 (‘Milton’[‘Lloyd George’  ‘Newburgh’]  ‘Cuthbert’)  ‘Durham’ (Plate 3B). ‘Heritage’ shows considerable vigor and fruits only on the tops of canes, presumably because of the ‘Newburgh’ and ‘Cuthbert’ background. The cultivar RubyTM (‘Watson’) was later developed using ‘Heritage’ and the floricane cultivar ‘Titan’ and had considerably larger fruit (Sanford et al. 1988). Development of primocane-fruiting cultivars continues in the CU program with multiple advanced selections currently being evaluated (C. Weber, pers. comm.). In New Hampshire, ‘Taylor’ was crossed with ‘Nectar’, a Boysenberry type, giving the primocane-fruiting apomictic seedling ‘Durham’ in 1944, which was released in 1947 (Brooks and Olmo 1947; Leemans and Nannenga 1957). Further breeding in New Hampshire resulted in the release of ‘Fallred’ (1964) and ‘Augustred’ (1973) from the cross of NH R7 (Durham  NY 102) [each derived entirely from ‘Taylor’]  NY 287 (NY 18810 [‘Marcy’  ‘Indian Summer’]  NY 20990 [a R. strigosus selection]) and ‘Fallgold’ (1967) from a cross involving ‘Taylor’, NH 56-1, and R. pungens Oldhami (Brooks and Olmo 1964, 1972, 1974). Each of these three cultivars has reduced height, relying on early flower initiation in new primocanes; ‘Augustred’ is extremely early when grown in a warm environment.

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Cultivars of primocane-fruiting red raspberries released in the United States up until 1969 were of poor-fruit quality. This prompted ‘‘Whitey’’ Lawrence to make crosses between primocane and floricane types to improve fruit quality (Lawrence 1976). No cultivars were released from the F1 hybrids of these crosses, but ‘Amity’, (1984) ‘Summit’ (1989) and ‘Chinook’ (2004) were produced in the F2 generation. Each of these cultivars has significantly improved fruit quality over cultivars available when the initial crosses were made in 1970 (Finn et al. 2004; Lawrence 1989a,b). Breeding of primocane-fruiting raspberries in the United States was also carried out in Maryland, resulting in the release of ‘Scepter’ (‘September’  ‘Durham’) and in Wyoming, resulting in the introduction of the cultivars ‘Trailblazer’ and ‘Pathfinder’ (both from ‘Augustred’  R. strigosus or derivatives) in 1967, prior to the program being discontinued in 1972 (Howard 1976; Lawrence 1980). Efforts in Wyoming utilized cold-hardy R. strigosus selections and R. deliciosus in breeding primocane-fruiting types in crosses with NH selections and germplasm from CU-NYSAES, but the program was curtailed before major advances were made using both sources of adaptation. In 1937, breeding for primocane-fruiting types was initiated by Earl V. Goldsmith and Joseph M. Reiter in the Santa Clara valley of California; the program ceased in 1953. Nevertheless, this work ultimately led to the patenting and commercial development of the ‘Sweetbriar’ (52–37x) and ‘Stonehurst’ cultivars by J. Miles Reiter in 1979 (Reiter 1979a,b), the basis from which DSA raspberry production was developed. ‘Sweetbriar’ was very vigorous, bearing fruit only on the top 30% to 40% of the primocanes and producing a dual crop on the remainder of the floricanes in the following spring. ‘Sweetbriar’ is of unknown origin, but canes and leaves show some similarity to ‘Cuthbert’ and its derivatives, ‘Sumner’ and ‘Chilcotin’. Other dual-cropping cultivars developed from ‘Lloyd George’ and ‘Ranere’ (‘St Regis’) are ‘Cherokee’, released in 1972 (Brooks and Olmo 1972; Oberle 1974) from Virginia and ‘Southland’ from North Carolina (Brooks and Olmo 1968; Hull 1969). Both cultivars were released as floricane types but have found use for their primocane crop as well. ‘Cherokee’ has been used for breeding in the WSU, PARC-BC, and CU-NYSAES programs as a source of root rot resistance, but not for its primocane-fruiting ability, giving rise to the floricane cultivar ‘Encore’ (H.K. Hall, pers. observ.; Weber et al. 1998). ‘Southland’ also has been used for breeding floricane-fruiting types, resulting in the release of ‘Nova’ from Nova Scotia and ‘Esta’ from Harry Swartz’s private ‘‘Five Aces’’ breeding program in Maryland (Brooks and Olmo

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1983; Daubeny 2002a). ‘Esta’ also produces a significant primocane crop in warmer climates. In 1955, work was begun on the investigation of the genetics of primocane fruiting at EMR in England by Elizabeth Keep (1961). Seedling progenies from crosses and selfed populations from ‘Lloyd George’ showed primocane fruiting to be present in almost all seedlings, some early and the majority later. Very few seedlings were non–primocane fruiting from ‘Lloyd George’ selfed. Primocane fruiting was present in all progenies in crosses of ‘Lloyd George’ and its selfed derivatives with non–primocane-fruiting parents. When the primocane-fruiting trait was present in other parents, the percentage of primocane fruiting was higher. When crosses were done with NY 21289 (L518), all the seedlings were primocane fruiting. NY 21289, like ‘Ranere’, was an early-fruiting R. strigosus selection. As with ‘Ranere’, use of NY 21289 promoted earlier primocane fruiting in crosses with ‘Lloyd George’ and its derivatives (Keep 1961). The earliest primocanefruiting selections were those in which flower initiation occurred early while canes were still elongating rapidly and temperatures were favorable for the ripening of fruit. Yield and quality of the selections developed from R. idaeus and R. strigosus background at EMR were not sufficient for any clone to be suitable for cultivar release (Keep 1976). Similar breeding in Switzerland yielded ‘Zeva Herbsternte’ from the cross ([‘Romy’ (‘Lloyd George’ selfed)  ‘Indian Summer’]  ‘Romy’), which, like ‘Heritage’, was unsatisfactory in the United Kingdom (Helliar and Turner 1984; Jennings 1988). Nevertheless, the cross of ‘Heritage’  ‘ Zeva Herbsternte’ in Poland was used to produce the selection 81221, later released as the cultivar ‘Polana’, which has become important in Italy (Danek 1989, 1991, 1999). Breeding of primocane-fruiting raspberries in eastern Europe has also been taking place, producing cultivars like ‘Lyulin’ [‘Newburgh’  ‘Bulgarski Rubin’ (‘Preussen’  ‘ Lloyd George’)]  ‘Heritage’ from Bulgaria and a range of new cultivars from the Russian Federation. These include ‘Abrikosovaya’, ‘Avgustina’, ‘Avgustovskoe Chudo’, ‘Aezusmuna’, ‘Bab’e Leto’, ‘Bab’e Leto 2’, ‘Brianskaya Yubileinaya’, ‘Brilliantovaya’, ‘E’legantnaya’, ‘Evraziya’, ‘Gerakl’, ‘Kalashnik’, ‘Nadeznaya’, ‘Oranzhevoe Chudo’, ‘Sentyabriskaya’, ‘Shapka Monomaha’, ‘Snegirek’, ‘Zarya Vecheriyaya’, ‘Zolotaya Osen’, ‘Zolotje Kupola’, and ‘Zuravlik’ (Kazakov 2006). At EMR, further earliness and cropping ability was sought from R. arcticus and R. odoratus (Keep 1976), resulting in the earliest selections beginning to crop in the second or third week of July. Some of the advance in earliness of primocane-fruiting types at EMR was

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through the development of shorter-growing, dwarfing types (Keep et al. 1980b). Increased yields of primocane fruit were also developed by crossing Russian primocane-fruiting R. idaeus clones with ‘Zeva’ and derivatives of ‘Lloyd George’ (Keep et al. 1980b). From the fifth generation of breeding from R. arcticus, ‘Autumn Bliss’ was produced from a 1974 cross and released in 1977, bringing together primocane-fruiting genetics developed at CU-NYSAES and at EMR (Keep 1984a). The release of ‘Autumn Bliss’ marked a watershed in the pursuit of productive, early primocane-fruiting types as it brought the season forward and considerably increased the yield in a cool temperate climate. When shifted to warmer climates, ‘Autumn Bliss’ produced a high yield during an early primocane-fruiting season, a significant advance on other available cultivars. However, ‘Autumn Bliss’ was lacking in fruit quality, with the fruit too dark, not as firm as better floricane cultivars, too hard to pick, especially for fresh market, and very spiny. When ‘Autumn Bliss’ was developed, Derek Jennings, at SCRI, crossed it with ‘Glen Moy’ to take advantage of genes for earliness and fruit quality from ‘Glen Moy’. This cross or its reciprocal was made and grown in Australia, New Zealand, the United States, and the United Kingdom. Cultivars released from this cross were ‘Aspiring’ in New Zealand, ‘Dinkum’ in Australia, and ‘Terri-Louise’ in the United Kingdom. In addition, one of the parents of ‘Caroline’, GEO-1, was produced from this cross, and the ‘Glen Moy’-‘Autumn Bliss’ combination was used in several other breeding programs. Other cultivars with ‘Autumn Bliss’ (‘AB’) as a parent include ‘Autumn Byrd’, ‘Babe Leto-2’ (Babe Leto  ‘AB’), ‘Bogong’ (‘AB’  Comox), ‘Carmen’ (‘AB’ selfed), ‘Favorite’ and ‘Galante’ (‘AB’  ‘Delmes’), ‘Gerakl’ (‘AB’  OP), ‘Himbo Top’ (‘AB’  ‘Himbo Queen’), ‘Kalashnik’ (‘AB’  OP), ‘Marcela’ (‘Joan Squire’  ‘AB’) ‘Princess’ (‘AB’  ‘Meeker’), and ‘Erika’ and ‘Sugana’ (‘Tulameen’  ‘AB’). Further cultivars that include ‘Autumn Bliss’ in their pedigree, include ‘Polka’ and ‘Pokusa’ from Poland and ‘Jaclyn’ from Maryland. ‘Malling Juno’ also is very early and has good fruit quality as well as offering possible resistance to RBDV (Knight and Ferna´ndez Ferna´ndez 2008a). This cultiva