The Effects of Wheat Cultivar Mixtures on the Population Genetic Structure of Puccinia Striiformis F. Sp. Tritici and Its Potential Ecological Mechanisms

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici (Pst), is an airborne disease threatening global wheat production. Cultivar mixtures are a sustainable strategy to enhance field genotypic diversity. Further research is needed to investigate the synergistic relationship between disease control and yield effects, as well as impacts on pathogen population structure. We conducted field experiments using four wheat cultivars with different resistance levels (Mingxian 169, Liangxing 208, Zhengmai 21, Shannong 184) with monocultures as controls and 12 mixture combinations, to evaluate stripe rust epidemics and yield performance. We also genotyped Pst isolates using simple sequence repeat (SSR) markers to assess population genetic shifts. Our results demonstrated that the area under the disease progress curve (AUDPC) was lower in seven cultivar mixture combinations, indicating disease control advantages. The mixture of moderately susceptible and highly resistant cultivars (M12) achieved the highest relative disease control efficacy (43.42