Abstract:To reveal mechanism of resistance to stripe rust in Xiaoyan54, which was inoculated with seven dominant races or strains of Puccinia striiforms f.sp. tritici prevalent in China, Xiaoyan54, susceptible cultivar Mingxian169 and their cross combinations were tested with races CYR32. RGAP markers were used to locate the resistance genes. The results showed that Xiaoyan54 expressed good disease resistance to seven dominant races or strains of PST at the adult stage. Genetic analysis of Xiaoyan54 indicated that resistance gene conferring to CYR32 was controlled by two independent recessive genes, temporarily designated as Yrxy54-1 and Yrxy54-2, respectively, and Yrxy54-1 was located. The parents, resistant and susceptible bulks were used for screening 528 RGAP primer combinations. The markers, M1, M2, M3, M4, were tightly linked to Yrxy54-1. Genetic distance from M1, M2, M3, and M4 to Yrxy54-1 were 15.8, 16.6, 7.3, and 9.97cM, respectively. Genetic analysis of Yrxy54-1 combined with RGAP markers supported the conclusion that Yrxy54-1 was a novel resistant gene which was different from other stripe rust resistance genes.