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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Disease and Pest Management Research Unit » Research » Publications at this Location » Publication #373335
Research Project: Integrated Disease Management of Exotic and Emerging Plant Diseases of Horticultural Crops

Location: Horticultural Crops Disease and Pest Management Research Unit

Title: Botrytis cinerea populations infecting small fruit hosts in the Pacific Northwest are highly structured on a local scale

Author
item KOZHAR, OLGA - Washington State University
item Larsen, Meredith
item Grunwald, Niklaus - Nik
item PEEVER, TOBIN - Washington State University

Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/13/2020
Publication Date: 4/17/2020
Citation: Kozhar, O., Larsen, M.M., Grunwald, N.J., Peever, T.L. 2020. Botrytis cinerea populations infecting small fruit hosts in the Pacific Northwest are highly structured on a local scale. Applied and Environmental Microbiology. 86(9):e02908-19. https://doi.org/10.1128/AEM.02908-19.
DOI: https://doi.org/10.1128/AEM.02908-19

Interpretive Summary: The fungus Botrytis cinerea causes gray mold on small fruit. In the Pacific Northwest, different small fruit crops are grown in close proximity, but nothing is known about the evolutionary history of this fungus on these hosts in the region. Populations of B. cinerea recovered from adjacent fields of red raspberry, blueberry, strawberry, blackberry, currants, grapes, and wild blackberry were characterized for genetic diversity and fungicide resistance. Population structure was assessed at local and regional scales and a correlation between fungicide use and genetic variation in the pathogen populations was studied. Populations overall were diverse, with no evidence for sexual recombination. Populations were unique to each field indicating a lack of migration among fields. Knowledge of population structure and its response to selection will help to improve gray mold management.

Technical Abstract: The fungus Botrytis cinerea, causal agent of gray mold, is the most important small fruit pathogen worldwide. In the Pacific Northwest, different small fruit crops are grown in close proximity, but nothing is known about the evolutionary forces shaping population structure of this fungus on these hosts in the region. Populations of B. cinerea recovered from adjacent fields of red raspberry, blueberry, strawberry, blackberry, currants, grapes, and wild blackberry were characterized for genetic diversity and fungicide resistance. Population structure at local and regional scales was assessed, and associations between fungicide use and the distribution of genetic variation were studied. Populations were diverse, with no evidence for recombination and no association of multilocus genotype with host. Populations were structured geographically and highly localized with limited migration among adjacent fields. Selection for fungicide resistance was detected. B. cinerea populations are highly diverse and present an efficient response to selection. In agroecosystems, pathogen populations undergo strong adaptation caused by fungicide use, that has a significant effect on their diversity and structure on a fine scale. Knowledge of population structure and its response to selection will help to improve gray mold management.