Association Analysis Identifies New Loci for Resistance to Chinese -Virulent Races of the Stripe Rust Pathogen in a Diverse Panel of Wheat Germplasm.

Stripe rust caused by f. sp. () is one of the most destructive fungal diseases of wheat worldwide. The expanding -virulent race (V26) group overcomes almost all currently deployed resistance genes in China and has continued to accumulate new virulence. Investigating the genetic architecture of stripe rust resistance in common wheat is an important basis for a successful utilization of resistance in breeding programs. A panel of 410 exotic wheat germplasms was used for characterizing new stripe rust resistance loci. This panel was genotyped using high-density wheat 660K single-nucleotide polymorphism (SNP) array, and phenotypic evaluation of seedlings for stripe rust resistance was performed using multiple races. Thirty-five loci conferring resistance were identified through genome-wide association mapping, and explained phenotypic variances ranged from 53 to 75%. Of these, 14 were colocated in the proximity of the known loci, including cataloged genes , , , , , , , , , , and and three temporarily designated as , , and detected in our quantitative trait locus (QTL) mapping studies. Seven of them (, , , , , , and ) were confirmed by molecular detection or genetic analysis. New loci that were identified to be different from reported genes need further confirmation. Nine QTL with significantly large phenotypic effect on resistance to all tested races were considered as major loci for effective resistance. The identified loci enrich our stripe rust resistance gene pool, and the linked SNPs should be useful for marker-assisted selection in breeding programs.