Markers Linked to Wheat Stem Rust Resistance Gene Sr11 Effective to Puccinia graminis f. sp. tritici

Wheat stem rust caused by Puccinia graminis f. sp. tritici can cause severe yield losses on susceptible wheat varieties and cultivars. Although stem rust can be controlled by the use of genetic resistance, population dynamics of P. graminis f. sp. tritici can frequently lead to defeat of wheat stem rust resistance genes. P. graminis f. sp. tritici race TKTTF caused a severe epidemic in Ethiopia on the Ug99-resistant cultivar ‘Digalu’ in 2013 and 2014. The gene Sr11 confers resistance to race TKTTF and is present in cultivar ‘Gabo 56’. We identified SNP markers linked to Sr11 from a cross between ‘Gabo 56’/‘Chinese Spring’ exploiting a 90K Infinium iSelect Custom beadchip. Twelve SNP markers were converted to KASP assays and five of them were validated on a ‘Berkut’/‘Scalavatis’ population that segregated for Sr11. Two of the SNP markers, KASP_6BL_IWB10724 and KASP_6BL_IWB72471, were predictive of Sr11 among wheat genetic stocks, cultivars, and breeding lines from North America, Ethiopia, and Pakistan. These markers can be utilized to select for Sr11 in wheat breeding and to detect the presence of Sr11 in uncharacterized germplasm.