Genetic Diversity of Puccinia striiformis f. sp. tritici Populations Sampled from Wheat-Producing Areas Using SSR Markers

Abstract

Stripe rust caused by Puccinia striiformis f. sp. tritici is one of the most destructive fungal diseases affecting wheat production worldwide, resulting in substantial yield and quality losses under favorable environmental conditions. The present study investigated the genetic diversity of P. striiformis f. sp. tritici populations collected from major wheat-producing areas using simple sequence repeat (SSR) molecular markers. Infected wheat leaf samples showing characteristic stripe rust symptoms were collected from different agroecological regions, and fungal DNA was extracted for molecular analysis. A set of polymorphic SSR markers was employed to evaluate genetic variability, allelic diversity, and population structure among pathogen isolates. The results revealed significant genetic variation within and among the sampled populations, indicating the existence of diverse pathogen genotypes across wheat-growing regions. Several SSR loci exhibited high polymorphism and discriminatory power, demonstrating their effectiveness in differentiating pathogen populations. Cluster and phylogenetic analyses grouped the isolates into distinct genetic lineages, suggesting possible regional adaptation and evolutionary divergence. Analysis of molecular variance indicated that most genetic variability existed within populations rather than between geographical regions. The occurrence of genetically diverse populations may enhance the adaptive potential of the pathogen and increase the risk of overcoming host resistance genes. The findings provide valuable insights into the population biology and epidemiology of P. striiformis f. sp. tritici and emphasize the importance of continuous pathogen monitoring. This study contributes to the development of durable resistance breeding programs and integrated disease management strategies for sustainable wheat production.