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ARS Home » Pacific West Area » Parlier, California » San Joaquin Valley Agricultural Sciences Center » Crop Diseases, Pests and Genetics Research » Research » Publications at this Location » Publication #424146
Research Project: Breeding Prunus and Vitis to Improve Disease Resistance, Fruit Quality, and Climate Change Adaptation

Location: Crop Diseases, Pests and Genetics Research

Title: Global genetic diversity and population structure of grapevine powdery mildew

Author
item Ordonez Aquino, Benny
item Mahaffee, Walter
item Cadle Davidson, Lance
item Dashner, Zachary
item WALKER, ANDY - University Of California, Davis
item Riaz, Summaira

Submitted to: American Journal of Enology and Viticulture
Publication Type: Abstract Only
Publication Acceptance Date: 3/27/2025
Publication Date: 6/1/2025
Citation: Ordonez Aquino, B.J., Mahaffee, W.F., Cadle Davidson, L.E., Dashner, Z.S., Walker, A., Riaz, S. 2025. Global genetic diversity and population structure of grapevine powdery mildew. American Journal of Enology and Viticulture. Presented at the American society of Enology and Viticulture, June 16-19, 2025, Monterey, CA.

Interpretive Summary:

Technical Abstract: Grapevine powdery mildew (PM), caused by Erysiphe necator, is one of the most destructive diseases in viticulture, threatening global wine, table, and raisin grape production. While previous studies provide regional and global assessments of its genetic diversity, key questions remain about its population structure, introduction history, and adaptation across viticulture regions. This study expands on prior work with a more comprehensive dataset of 410 samples from North and South America, Europe and Australia, leveraging 20 microsatellite markers to refine our understanding of PM diversity at global level. Our findings verified a distinct genetic separation between Eastern and Western USA, reinforcing the hypothesis of an Eastern North American origin. We also uncover higher genetic diversity in California and Oregon than previously reported, suggesting multiple introduction events or increased recombination within Western USA. Furthermore, we provide the first genetic characterization of Australian E. necator populations, identifying a unique cluster shaped by long-term isolation and distinct introduction history. Our results suggest that evolving E. necator populations may impact the effectiveness of disease management strategies, particularly changing environment and fungicide selection pressure. This study enhances our understanding of E. necator population dynamics, providing valuable insights for the development of region-specific disease control strategies and sustainable viticultural practices.