Exploring Diversity of Bacterial Spot Associated Population of Pepper in Southwest Florida.

Bacterial spot caused by spp. is a significant disease that challenges pepper growers worldwide and is particularly severe in a hot and humid environment. Understanding the pathogen's population biology is critical for sustainable disease management. The goal of this study was to characterize the species, race, and bactericide sensitivity of bacterial spot-associated collected from pepper in Florida. A survey of pepper production fields in southwest Florida between 2019 and 2021-covering two counties, eight farms, and two transplant facilities-resulted in the isolation of 542 and 35 strains. Four races were identified on pepper, of which most strains were race P1 (42%), race P6 (26%), race P3 (24%), and less common was race P4 (8%). All strains were characterized as race P1 and showed a compatible reaction on tomato. Sixty-two and 96% of strains were sensitive to copper sulfate and streptomycin, respectively. One farm that did not use copper to manage the disease contained only copper-sensitive strains and was the only farm with race P3 strains. Strains were assayed for starch hydrolysis activity of which a third of strains were strongly amylolytic, a characteristic not typically observed in . All strains produced bacteriocins against in vitro. The population causing bacterial spot on pepper in southwest Florida is diverse and dynamic; thus, regular monitoring provides pertinent information to plant breeders and growers for designing disease management strategies.