Virulence and genetic characterization of Puccinia striiformis f.sp. tritici populations on different wheat cultivars

Abstract Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici ( Pst ), is a major global threat to wheat production, severely affecting yield stability. This study analyzed the virulence and genetic characteristics of Pst populations on five wheat cultivars during 2020 and 2021. A total of 116 pathotypes were identified among 384 isolates using a set of 24 differential lines. The pathotype distribution varied widely among the cultivars, with only four pathotypes shared across all five cultivars in 2020 and three in 2021. The diversity of Pst populations differed significantly between cultivars. In 2020, the population diversity on the moderately resistant cultivars Lantian17 and Zhengmai9023 was higher than on the highly susceptible cultivar Mingxian169, moderately susceptible cultivar Xiaoyan22 and highly resistant cultivar Lantian19. In contrast, during the severe stripe rust outbreak in 2021, the highest population diversity was observed on the highly resistant cultivar Lantian19. Significant genetic differentiation was observed using F ST analyses of Simple Sequence Repeats (SSR) markers data among populations on the different cultivars, but cultivar-specific clustering was not detected. These findings provide novel insight into the interactions between Pst populations and their hosts and offer valuable guidance for deploying wheat cultivars to effectively manage stripe rust.