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ARS Home » Midwest Area » East Lansing, Michigan » Sugarbeet and Bean Research » Research » Publications at this Location » Publication #395153

Research Project: Genetic Characterization for Sugar Beet Improvement

Location: Sugarbeet and Bean Research

Title: Fungicide resistance and host influence on population structure in Botrytis spp. from specialty crops in California

item Naegele, Rachel
item Abdelsamad, Noor
item Delong, Jeffery - Jeff
item Saito, Seiya
item Xiao, Chang-Lin
item MILES, TIM - Michigan State University

Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2022
Publication Date: 12/20/2022
Citation: Naegele, R.P., Abdelsamad, N.A., DeLong, J.A., Saito, S., Xiao, C., Miles, T. 2022. Fungicide resistance and host influence on population structure in Botrytis spp. from specialty crops in California. Phytopathology. 112(12):2549-2559.

Interpretive Summary: Botrytis is a plant pathogen that can infect more than 200 species of crops including small fruits like strawberries, blueberries, grapes, and raspberries. Managing this pathogen can be challenging since fungicide resistance is common and it can infect many species. This study looked at how fungicide resistance differs based on the type of crop and found that fungicide resistance was more common in strawberries compared to grapes and blueberries. In addition, we found evidence that there were genetic differences between isolates of Botrytis that go to blueberry and those that go to strawberry and grape. The genetic markers and fungicide resistance data collected in this work will be used to develop robust management programs to help reduce fungicide resistance and diagnostic markers associated with multi-fungicide resistance.

Technical Abstract: Botrytis is an important genus of plant pathogens causing pre- and postharvest disease on diverse crops worldwide. This study evaluated Botrytis isolates collected from strawberry, blueberry, and table grape berries in California. Isolates were evaluated for resistance to eight different fungicides, and 60 amplicon markers were sequenced (neutral, species identification, and fungicide resistance associated) distributed across 15 of the 18 B. cinerea chromosomes. Fungicide resistance was common among the populations, with resistance to pyraclostrobin and boscalid being most frequent. Isolates from blueberry had resistance to the least number of fungicides, whereas isolates from strawberry had resistance to the highest number. Host and fungicide resistance-specific population structure explained 12 and 7 to 26%, respectively, of the population variability observed. Fungicide resistance was the major driver for population structure, with select fungicides explaining up to 26% and multiple fungicide resistance explaining 17% of the variability observed. Shared and unique significant single-nucleotide polymorphisms (SNPs) associated with host and fungicide (fluopyram, thiabendazole, pyraclostrobin, and fenhexamid) resistance-associated population structures were identified. Although overlap between host and fungicide resistance SNPs were detected, unique SNPs suggest that both host and fungicide resistance play an important role in Botrytis population structure.