P-061 - Identifying Genetic and Phenotypic Diversity of Ampelomyces quisqualis to Enhance Biocontrol Strategies for Powdery Mildew

Powdery Mildew fungi (PM) are obligatory plant parasites, causing widespread disease and death to critical species. Powdery mildew has wide economic and agricultural implications for multiple important crops. Current pathogen management primarily depends on fungicide applications. Ampelomyces quisqualis, a mycoparasite and known biocontrol of PM, infects PM structures, and suppresses the pathogen’s spread. Previous PM-Ampelomyces research was limited by small-scale collections of Ampelomyces strains, from limited geographic regions, leaving an incomplete understanding of the genetic diversity and evolutionary dynamics. To address this, we are establishing a culture collection of Ampelomyces isolates from varied regions of the United States. Towards addressing this we screened, with Ampelomyces specific primers, nearly 800 PM samples from herbarium specimens collected throughout the world with an emphasis on North American collections. Approximately 13% showed Ampelomyces infection. Interestingly, we observed certain PM genera were more likely to harbor Ampelomyces than others, and previously these genera were not reported to harbor Ampelomyces. We proceeded to sequence multiple regions of these Ampelomyces specimens revealing greater diversity than originally detected from previous analyses focusing on cultured specimens and from single geographic localities. This research is essential for understanding the population diversity of this significant mycoparasite and will lay the groundwork for future studies aimed at enhancing its effectiveness as a biological control agent.