Genome Wide Association Study of Resistance to PstS2 and Warrior Races of Stripe (Yellow) Rust in Bread Wheat Landraces

Abstract

Stripe rust, caused by Puccinia striiformis Westend. f. sp. tritici is a major threat to wheat production worldwide. The breakdown in resistance of certain major genes and new emerging aggressive races of stripe rusts are causing serious concerns in all main wheat growing areas of the world. To search for new sources of resistance genes and associated QTL for effective utilization in future breeding programs an association mapping panel comprising of 600 bread wheat landraces collected from eight different countries conserved at ICARDA gene bank were evaluated for seedling and adult plant resistance against PstS2 and Warrior races of stripe rust at the Regional Cereal Rust Research Center (RCRRC), Izmir, Turkey during 2016, 2018 and 2019. A set of 25,169 informative SNP markers covering the whole genome were used to examine the population structure, linkage disequilibrium and marker-trait associations in the association mapping panel.The genome-wide association study (GWAS) was carried out using a Mixed Linear Model (MLM). We identified 47 SNP markers at 19 genomic regions with significant SNP-trait associations for both seedling and adult plant stage resistance, the threshold of significance for all SNP-trait associations was determined by the false discovery rate (q) ≤ 0.05. Three genomic regions (QYr.1D_APR, QYr.3A_seedling and QYr.7D_seedling) identified in this study are far away from any previously reported Yr gene or QTL hence, tagging novel genomic regions. TheIn-silico analysis of the novel QTL regions identified candidate resistance genes encoding proteins putative to plants disease resistance and defense mechanism.

Comparison of Genomic Prediction Methods for Yellow, Stem, and Leaf Rust Resistance in Wheat Landraces from Afghanistan

“…Wheat is one of the most important cereal crops of the world, grown from the Equator to the Arctic Circle, and considered a staple food of 35% of the world population, which serves as the major source of carbohydrates in the human diet [ 1 , 2 ]. The three rust diseases of wheat, namely yellow rust (Yr), stem rust (Sr), and leaf rust (Lr), are a continuous threat to wheat production around the world [ 3 ].…”

Quantitative trait loci for yellow rust resistance in spring wheat doubled haploid populations developed from the German Federal ex situ genebank genetic resources

“…The aggressive, high temperature‐adapted race PstS2 and the new virulent races PstS10 and PstS7 [Warrior (–), Warrior] are the most widely spread pathotypes of Pst covering geographical regions from Asia to Northern Europe (Hovmøller et al., 2016; Tadesse et al., 2014; Tehseen et al., 2021). The Warrior race was first discovered in the UK in 2011 and is currently the most prevalent race of Pst in Europe (Ali et al., 2017).…”