SNP-Based Association Analysis for Stripe-Rust Resistance in Wild Emmer Wheat, Triticum dicoccoides L.

Stripe rust is one of the most destructive fungal diseases afflicting wheat production in many regions of the world. Breeding resistant cultivars is the most effective, economical and environment-safe approach for controlling the stripe-rust disease. Continuous identification and application of novel resistance resources/ genes against stripe rust are of great importance for wheat breeding. Association mapping is a powerful approach for discovering and mapping resistance genes/QTLs based on linkage disequilibrium (LD) in molecular plant breeding. In the present study, association analysis was performed for stripe-rust resistance in a sample population of 350 wild emmer wheat accessions collected from the Fertile Crescent using a total of 1,018 amenable SNP markers. A total of 28 SNP loci identified were significantly associated with stripe-rust resistance. Three of them were found in the same chromosome bins where stripe-rust resistance gene/QTLs had been previously reported. The remaining 25 associations appear at the unreported locations and may therefore represent new loci. Furthermore, some evidence for novel loci, such as quantitative RT-PCR analysis, was presented. Although the roles of these new loci need to be further investigated, this information coupled with the next analysis of haplotype profiles of segregating populations/breeding lines will offer novel opportunities for marker-assisted selection. On the other hand, we identified some promising stripe-rust resistance resource that will be a useful core germplasm for mining resistance genes and further studies on breeding utilization in wheat improvement.