Pacific Agri-Food Research Centre Research Articles

New Variant of Little cherry virus Associated with Little Cherry Disease of Sweet Cherry in British Columbia, Canada.

Little cherry disease (LChD) occurs in most cherry growing areas in the world. Infection of sensitive cultivars results in small fruit with poor color, angular shape, and insipid flavor. Three viruses associated with LCD have been described: (i) Little cherry virus-1 (LChV-1) first found and described in Germany (4); (ii) LChV-2 an isolate obtained from the United States (2); and (iii) LChV-3 first found and described in British Columbia (1). Despite similarities in symptom development in orchard trees and woody indexing, the three viruses have distinct molecular sequences (3). LChV-2 and -3 share greater homology with each other than either does with LChV-1. For many years, the British Columbia Ministry of Agriculture, Fisheries and Food (BCMAFF) in conjunction with Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre (AAFC-PARC) has conducted a survey to monitor the incidence and spread of LChD in the Okanagan and Kootenay valleys of British Columbia, Canada. Until recently, testing for LChD used woody indexing on indicator trees, Prunus avium cv. Lambert (fruit symptoms) and cvs. Canindex1 and Sam (foliar symptoms). Recently, incidence of LChD has been evaluated using double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) developed at AAFC-PARC (3), and reverse transcription-polymerase chain reaction (RT-PCR) tests based on sequence data from LChV-3 (1). During the 1999 survey, orchard trees displaying symptoms typical of LChD tested negative for LChV-3 using ELISA and RT-PCR. Also, trees that formerly tested positive for LChD by woody indexing also tested negative for LChV-3 using RT-PCR and ELISA. Two hundred ninety-three trees were subsequently tested for LChV-1 by RT-PCR using the primer set LCV3EC/LCV16659 (4). A 276-bp fragment corresponding to the extreme 3' untranslated region (3' UTR) of the LChV-1 genome was amplified by RT-PCR from 140 of the trees. The RT-PCR amplicon from one sample (#99-68B from Peachland) was sequenced and using a BLASTn search, LChV-1 was identified as the most probable match (E value 4e-59). Sequence alignment using ClustalX identified two regions of high sequence homology; bases 2 to 70 (92%) and bases 99 to 239 (95%). The intervening region displayed much lower homology (61%). The overall homology of the amplicon was 88% compared to the corresponding region in LChV-1. Divergence between the published sequence of LChV-1 and the sequence of the new LChV isolate (tentatively named LChV-4) was investigated. Seven sets of primers constructed on the basis of sequence data from various regions of the LChV-1 genome (two sets from each of the RNA-dependent RNA polymerase, heat shock 70 protein homologue, and coat protein) failed to yield RT-PCR products when tested with the LChV-4 isolate. LChV-4 is clearly related to LChV-1 within the 3'-UTR but complete sequencing is required to determine the overall relationship with other viruses causing LChD. The discovery of a new isolate of LChV in British Columbia may require a reevaluation of the epidemiology of LChD and disease management strategy.

The Canadian Phytopathological Society Annual Meeting, Waterton Lakes National Park, Alberta, 2002

The Canadian Phytopathological Society Annual Meeting, Waterton Lakes National Park, Alberta, 2002

Genetic Analysis and Discrimination of Sweet Cherry Cultivars and Selections Using Amplified Fragment Length Polymorphism Fingerprints

Amplified fragment length polymorphisms (AFLPs) were used to analyze the relationships between sweet cherry (Prunus avium L.) cultivars and selections from the breeding program at the Pacific Agri-Food Research Centre in Summerland, Canada. Six pairs of preselected primers were used for the analysis of a total of 67 cultivars and selections. Scoring the absence and presence of 118 polymorphic DNA fragments produced a unique binary code for each cultivar and selection. Two phylogenetic trees were constructed using these 118 polymorphic fragments, one tree for 55 related cultivars and selections from the Summerland breeding program and the other for 23 self-incompatible cultivars of differing origins. The reliability of AFLP DNA fingerprints was confirmed by correlating relationships revealed by AFLP profiles with known genetic relationships of some sweet cherry cultivars and by a blind test for cultivar identification. Results indicate that AFLP analysis is a good technique to evaluate genetic distance and relationships in a sweet cherry breeding population.

British Columbia Regional Meeting, 2001, The Canadian Phytopathological Society / Réunion régionale de la Colombie-Britannique, 2001, La Société Canadienne de Phytopathologie

British Columbia Regional Meeting, 2001, The Canadian Phytopathological Society / Réunion régionale de la Colombie-Britannique, 2001, La Société Canadienne de Phytopathologie

Abstracts, The Canadian Phytopathological Society annual meeting, London, Ontario, 2001

Abstracts, The Canadian Phytopathological Society annual meeting, London, Ontario, 2001

A novel technique for evaluation of apple (Malus × domestica Borkh.) cultivars for susceptibility to powdery mildew

A technique for the evaluation of apple cultivars for susceptibility to powdery mildew caused by Podosphaera leucotricha (Ell. & Ev.) E. S. Salmon (anamorph Oidium farinosum Cooke) was tested at the Pacific Agri-Food research Centre (PARC), Summerland, BC. Shoots of test cultivars [Braeburn, Creston, Elstar, Empire, Fuji strain BC2, Gala strain Royal, Jonagold, McIntosh, Delicious red strain Bisbee, Shamrock, Silken, Sunrise, and one breeding selection (11w-17-85)], approximately 6 cm in length, were grafted on to branches of mature Jonagold trees in the spring and evaluated in the summer of the same year and in subsequent years after growth on the host tree. Incidence and severity of powdery mildew were evaluated in 1994, 1995, 1997, and 1998. They were not evaluated in 1996 because approximately half the grafts from the previous year did not grow and had to be replaced. The highest incidence of powdery mildew averaged 84% for Gala, compared with only 15% for Bisbee Delicious with the lowest incidence. Gala had the highest number of P. leucotricha conidia per cm2 of leaf area (4.9 × 104) compared to Bisbee Delicious (1.2 × 104). Some of the grafted cultivars were also evaluated for primary powdery mildew and fruit russetting in 1998 after the growth for three seasons. Jonagold had the highest numbers of primary infections and russetted fruit. Key words: Podosphaera leucotricha, breeding, cultivar resistance, pest management

`Malahat' Red Raspberry

Received for publication 25 June 1999. Accepted for publication 28 Oct. 1999. This research was partially funded by the Lower Mainland Horticultural Improvement Association and the British Columbia Raspberry Growers’ Association. We gratefully acknowledge the assistance of B. Harding, S. Elliott, S. Wahlgren, and A. Levesque of Pacific Agri-Food Research Centre; P. Moore, Washington State Univ., Puyallup; C. Finn and R. Martin, U.S. Dept. of Agriculture, Corvallis, Ore. This is Pacific Agri-Food Research Centre Contribution no. 607. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. ‘Malahat’ Red Raspberry

`Sumste Samba', `Sandra Rose', and `Sumleta Sonata' Sweet Cherries

Received for publication 4 Jan. 1999. Accepted for publication 29 Apr. 1999. Contribution no. 2014 of the Pacific Agri-Food Research Centre. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement solely to indicate this fact. ‘Sumste Samba’, ‘Sandra Rose’, and ‘Sumleta Sonata’ Sweet Cherries

Weather conditions associated with apple production in the Okanagan Valley of British Columbia

An analytical method that generates χ2 indices of association was used to determine the "critical" levels of daily weather occurrences associated with annual variations in apple production (Malus domestica Borkh.) in the Okanagan Valley of British Columbia over a 72-yr period, 1920–1991. The weather was recorded in the centre of the region (the Pacific Agri-Food Research Centre, Summerland). High temperatures during flower bud initiation in June (≥30 °C) and during flower bud development in August (≥26 °C) were associated with poor production the following year. Low temperature during November, December and February (critical value range, ≤ −7 °C to ≤ −29 °C) was the main climatic factor limiting apple production. These time periods correspond to the occurence of historical winter injury events. Daytime temperatures ≥5 °C at times during January also affects apple production adversely, probably because warm weather leads to tree deacclimation. Daily precipitation in March (≥1.0 mm) was associated with good production years which may indicate a requirement for early irrigation. Production was favoured by mild temperatures during bloom (≥21 °C daytime, ≥11 °C nighttime) and adversely affected by both very low temperatures (≤10 °C nighttime) and unseasonably high temperatures (≥28 °C daytime) coinciding with the temperature requirements of pollination and pollen tube growth. Good production years were also associated with a lack of low nighttime temperature (≤5 °C) in spring, probably associated with frost in low lying areas. Hot, dry weather during August of the harvest year (≥33 °C daytime, ≤2 mm) had a negative impact on apple production possibly because of loss in net photosynthesis, lower fruit size or apple sunburn. Warm weather during harvest (≥17 °C daytime) favoured production, probably because of improved conditions for harvest operations and low fruit losses from autumn frosts. Key words: Malus domestica Borkh., tree fruit, climate, heat stress, spring frost, winter injury

Abstracts, British Columbia Regional Meeting, The Canadian Phytopathological Society, 1997

Ustilago hordei; use of RAPD and AFLP technology for tagging and fingerprinting in smuts and other fungi. G. Bakkeren, D. Lin, N. Lee, M. Abdennabher, D. Gaudet, P. Thomas, D. Mills, C. A. Lévesque, and J. Kronstad. (G.B. and C.A.L.) Pacific Agri-Food Research Centre, Agriculture & Agri- Food Canada, Summerland, B.C. VOH 1Z0, (G.B., D.L., N.L., and J.K.) Biotechnology Laboratory, Departments of Microbiology and Immunology, and Plant Science, University of British Columbia, Vancouver, B.C. V6T 1Z3, (M.A. and D.M.) Department of Botany and Plant Pathology, Oregon State University, Corvallis, Oregon, USA 97331, (D.G.) Research Station, Agriculture & Agri-Food Canada, Lethbridge, Alberta, TIJ 4B1, (P.T.)Agriculture & Agri- Food Canada, Research Station Winnipeg, Manitoba, R3T 2M9. Tomato ringspot nepovirus protease demonstrates different level of tolerance to amino acid substitution at two polyprotein cleavage sites. K. Carrier and H. Sanfacon. Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH 1Z0. Development of PCR primers specific for Pezicula malicorticis and P. perennans, fungal species associated with anthracnose and perennial cankers of apple and bull's eye rot of apple fruit. S. N. de Jong, C. A. L&vesque, and J. E. Rahe. Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, B.C. V5A 1S6, (C.A.L.) Pacific Agri-Food Research Centre, Agriculture and Agri- Food Canada, Summerland, B.C. VOH 1Z0. First record of Pythium paddicum isolated from turfgrass roots collected from a British Columbia golfcourse. R. C. Descalzo, I. W. Geere, G. Geere, and C.A. L&vesque. I.G. MicroMed Environmental Inc., 190-12860 Clarke Place, Richmond, B.C., V6V 2H1, (C.A.L.) Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH 1Z0. Control of the root lesion nematode Pratylenchus penetrans with antagonistic rhizobacteria. C. Hackenberg, T. Forge, A. Muehlchen, and T. Vrain. Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH 120. A novel host-based identification and detection system using cranberry pathogens as a model. C. E. Harlton, Y. Ahn, and C. A. L&vesque. Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH IZ The sexual stage of Pezicula malicorticis on anthracnose cankers. K. Jurkemikova and J. E. Rahe. Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, B.C. V5A 1S6. Development of commercial biocontrol products; synergy in action, "Mickey" a case study. M. Leggett. Philom Bios Inc., 318-111 Research Drive, Innovation Place, Saskatoon, Saskatchewan S7N 3R2. A survey of blueberry fruit rot in British Columbia — implications for management. L. Macdonald. B.C. Ministry of Agriculture, Fisheries and Food, 1767 Angus Campbell Road, Abbotsford, B.C. V3G2M3. Microbiological aspects of apple replant disease and the potential for control through the use of integrated management Strategies. M. Mazzola. USDA-ARS, Tree Fruit Research Lab, 1104 N. Western Ave., Wenatchee, WA 98801. Abiotic considerations for overcoming replant problems in high density orchard systems. G. H. Neilsen, E. J. Hogue, D. Neilsen, and B. J. Zebarth. Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH Molecular approach to monitor a beneficial Penicillium species. D. O'Gorman, M. Leggett, and C. A. Lévesque Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summerland, B.C. VOH IZO; (M.L.) Philom Bios Inc., 318-111 Research Drive, Innovation Place. Saskatoon, Saskatchewan S7N 3R2. Development of fusarium crown and root rot, a new disease on greenhouse cucumbers in British Columbia. Z. K. Punja and K. Ng. Department of Biological Sciences, Centre for Pest Management, Simon Fraser University, Burnaby, B.C. V5A 1S6, and (K.N.), B.C. Ministry of Agriculture, Fisheries and Food, Abbotsford, B.C. V3G 2M3. Revisiting Pythium taxonomy, identification and ecology. A. Quail, C. Mayes, and C. A. Lévesque. Pacific Agri-Food Research Centre, Agriculture and Agri-Food Canada, Summer/and, B.C VOH1Z0. Geographic variation in the mitochondrial DNA of Chondrostereum purpureum . T. D. Ramsfield, Z. K. Punja, S. F. Shamoun, and W. E. Hintz. Centre for Pest Management, Department of Biological Sciences, Simon Fraser University, Burnaby, B.C., V5A 1S6, (S.F.S.) Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, B.C., V8Z 1M5, (W.E.H.) Biology Department, University of Victoria, Victoria, B.C. V8W3N5. Binding of cucumber necrosis virus to zoospores of its fungal vector in vitro. M. Robbins and D. Rochon. Department of Plant Science, University of British Columbia, Vancouver, B.C., V6T 2A2, and Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, B.C. VOH IZ0. Latent infection of apples and stone fruit in British Columbia in 1997. P. Sholberg, K. Bedford, L. Lashuk, and P. Haag. Agriculture and Agri-Food Canada, Pacific Agri-Food Research Centre, Summerland, B.C., VOH 1Z0.

Abstracts, The Canadian Phytopathological Society, annual meeting, Winnipeg, Manitoba, July 1997

Abstracts, The Canadian Phytopathological Society, annual meeting, Winnipeg, Manitoba, July 1997

Abstracts, British Columbia Regional Meeting, The Canadian Phytopathological Society, 24-25 October 1996

Survey of British Columbia ornamental nurseries for watermelon mosaic virus 2 in wisteria. D.Dinh, J.F.Elmhirst, and D.J.Ormrod. B.C. Ministry of Agriculture, Fisheries and Food, 1767 Angus Campbell Road, Abbotsforci British Columbia V3G 2M3. Development of DNA diagnostics for detecting Fusarium in conifer nursery environments. Gary C. Donaldson, Paige E. Axelrood, and N. Louise Glass. Department of Plant Science, University of British Columbia, Vancouver, V6T 1W4, (G.C.D. and P.E.A.) B.C. Research Inc., Vancouver, V6S 2L2; and (N.L.G.) Botany Department and Biotechnology Laboratory, University of British Columbia, Vancouver, V6T IW3. Identification of a protein associated with frost hardiness of western white pine as a pathogenesis-related protein in the white pine blister rust pathosystem. Abul K.M. Ekramoddoullah, Joanne J. Davidson, and Doug W. Taylor. Natural Resources Canada, Canadian Forest Service, Pacific Forestry Centre, 506 West Burnside Road, Victoria, British Columbia V8Z IM5. A new strain of fusarium crown and root rot on greenhouse tomatoes. J.F. Elmhirst. B.C. Ministry of Agriculture, Fisheries and Food, J767 Angus Campbell Rd., Abbotsford, British Columbia V3G 2M3. Reverse dot-blot hybridization for fungal identification and detection: a novel technique for mycological research. C. André Lévesque. Pacific Agri-Food Research Centre, Agriculture ° Agri-Food Canada, Summerland, British Columbia VOH 1Z0 Failure of fungicides to control anthracnose canker of apple. James E. Rahe. Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6. Occurrence of scab on apple cultivars with Vf scab resistance in coastal British Columbia. James E. Rahe. Department of Biological Sciences, Simon Fraser University, Burnaby, British Columbia V5A 1S6. 1996 Fraser Valley potato late blight control trials. C Thomson, D. Zgrablic, J. Koeman and D. Ormrod. B.C. Ministry of Agriculture, Fisheries & Food, 1767 Angus Campbell Rd., Abbotsford, British Columbia V3G 2M3.