Mapping of Stripe Rust and Leaf Rust Resistance Genes in the Hard Red Winter Wheat Population Green Hammer × Lonerider

Stripe rust and leaf rust, caused by Puccinia striiformis f. sp. tritici and P. triticina , respectively, are the most destructive wheat diseases in the southern Great Plains. ‘Green Hammer’ is a hard red winter wheat (HRWW) cultivar released by Oklahoma State University in 2018 and has demonstrated a stable adult plant resistance to stripe rust and race-specific seedling resistance to leaf rust. To identify and map rust resistance loci, 109 doubled haploid (DH) lines derived from the cross between Green Hammer and another HRWW cultivar, ‘Lonerider’, were developed. Lonerider showed adult plant resistance to stripe rust but was susceptible to multiple P. triticina races. The DH lines were evaluated for stripe rust at the adult plant stage in greenhouse and field environments across Oklahoma, Kansas, and Washington, and for leaf rust at the seedling stage against seven U.S. P. triticina races and at the adult plant stage in Oklahoma and Texas. Genotyping-by-sequencing generated 6,078 polymorphic single-nucleotide polymorphisms used for genetic mapping. Quantitative trait loci (QTL) analysis identified 14 stripe rust and eight leaf rust resistance QTL. For stripe rust, a major QTL in Green Hammer, QYr.osughln-2AS , was identified in the proximity of the 2NvS translocation. Two major stripe rust resistance QTL were identified in Lonerider on chromosomes 2AL and 2BS. For leaf rust, QLr.osughln-1DS and QLr.osughln-2DS.1 were the two major QTL identified in Green Hammer and likely correspond to the all-stage resistance genes Lr21 and Lr39 , respectively.