Molecular mapping of stripe rust resistance gene YrH922 in a derivative of wheat (Triticum aestivum)–Psathyrostachys huashanica

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici Erikss (Pst), is one of the most damaging diseases in common wheat (Triticum aestivum L.) globally. Breeding for genetic resistance is the most effective, economical and ecologically sustainable method to control the disease. The wheat line H922-9-12, developed from a cross between Psathyrostachys huashanica Keng and T. aestivum, was highly resistant to nine Pst races in tests at the seedling stage. To characterise and map the stripe rust resistance gene(s) in H922-9-12, segregating populations were developed by crossing H922-9-12 with the susceptible cultivar Mingxian 169. When tested with Pst race CYR34, the stripe rust resistance in H922-9-12 was shown to be controlled by a single dominant gene, provisionally designated YrH922. A linkage map was constructed with five simple sequence repeat, six expressed sequence tag (EST) and two sequence-related amplified polymorphism markers. YrH922 was located on chromosome 3BL and was 2.7 and 3.4 cM proximal to EST-STS (sequence-tagged site) markers BE517923 and BE471045, respectively. The flanking marker BE517923 in marker-assisted selection for the gene can be used to improve stripe rust resistance on breeding programs.