Virulence and genetic analysis of Puccinia graminis tritici in the Indian sub-continent from 2016 to 2022 and evaluation of wheat varieties for stem rust resistance

Wheat stem rust, caused by Puccinia graminis f. sp. tritici ( Pgt ), has re-emerged as one of the major concerns for global wheat production since evolution Ug99 and other virulent pathotypes from East Africa, Europe, Central Asia, regions. Host resistance is most effective, economic, eco-friendly approach managing rust. Understanding virulence nature, genetic diversity, origin, distribution, evolutionary pattern over time space a prerequisite effectively newly emerging isolates through host resistance. In present study, we monitored occurrence rust in India neighboring countries 2016 to 2022, collected 620 single-pustule six states Nepal, analyzed them on Indian differentials, determined their phenotypes molecular genotypes. The type did not occur India. Pathotypes 11 40A were predominant during these years. Virulence phenotyping identified 14 pathotypes, which genotyped using 37 spp.-specific polymorphic microsatellites, followed additional phylogenetic analyses DARwin. These three groups, demonstrating fewer lineages, clonality, long-distance migration Fourteen 40 recently released varieties exhibited complete all 23 at seedling stage. Twelve Sr genes postulated 39 based response pathotypes. values slow rusting parameters i.e. coefficient infection, area under disease progress curve, infection rates, assessed adult plant stage five geographically different locations two crop seasons, indicated behavior several varieties. Six Sr2 , Sr57 Sr58 Sr24 Sr31 Sr38 ) 24 markers closely linked genes. findings will guide future breeding programs toward more effective management