Favorable Loci Identified for Stripe Rust Resistance in Chinese Winter Wheat Accessions Via Genome-Wide Association Study

Abstract

Stripe rust (or yellow rust), caused by Puccinia striiformis f. sp. tritici (Pst), is one of the most devastating diseases of wheat worldwide. Currently, the utilization of resistant cultivars is the most viable way to reduce yield loss. In this study, a panel of 188 wheat accessions from China were evaluated for stripe rust resistance, and genome-wide association studies (GWAS) were performed using high-quality Diversity Arrays Technology (DArT) markers. According to the phenotype and genotype data, a total of 26 significant marker-trait associations were identified, representing 18 quantitative trait loci (QTLs) on chromosomes 1B, 2A, 2B, 3A, 3B, 5A, 5B, 6B, 7B, and 7D. Of the 18 QTLs, almost all were associated with adult plant resistance (APR) except QYr.nwsuaf-6B.2, which was associated with all-stage resistance (ASR, also known as seedling resistance). Three of the 18 QTLs were mapped far from previously identified Pst resistance genes/QTLs and were considered potentially new loci. The other 15 QTLs mapped close to known resistance genes/QTLs. Subsequent haplotype analysis for QYr.nwsuaf-2A and QYr.nwsuaf-7B.3 revealed the degrees of resistance of the panel in the APR stage. In summary, the favorable alleles identified in this study may be useful in breeding for disease resistance to stripe rust.