Identification of a stripe rust resistance gene YrSF in Chinese wheat (Triticum aestivum) landrace Sifangmai

Wheat stripe rust is an important disease and can seriously threaten wheat production. The most economical, safe and effective approach to manage this disease is to breed and deploy resistant varieties. Sifangmai is a Chinese wheat landrace and maintained adequate resistance to the Chinese stripe rust races. In order to decipher genetic bases of resistance in Sifangmai, the F-1, F-2 and F-2:3 of the cross Sifangmai/Taichung 29 were tested at adult stage with race CYR32. Genetic analysis revealed that resistance in Sifangmai was controlled by a single dominant gene named as YrSF. Six SSR on chromosome 5BS showed polymorphism among 'Taichung 29', Sifangmai, and resistant and susceptible bulks. Chinese Spring nulli-tetrasomic and monosomic lines were confirmed YrSF on chromosome 5B. A linkage map of YrSF was constructed and the closely linked marker to YrSF was Xgpw8015 with 1.8 cM. Based on the comparisons of resistance infection type, pedigree analysis, gene origin and chromosomal position of previously reported Yr genes on chromosome 5B, YrSF is different from these known genes and is likely a novel gene.