Molecular Mapping Of A Recessive Resistance Gene In One Emmer Accession

Powdery mildew, caused by Blumeria graminis (DC.) E.O. Speer f. sp. tritici, is one of the most important diseases of common wheat world-wide. Breeding for resistance cultivars has been proven to be the most effective way to control this disease, for which screening for and utilization of diverse resistance genes are the prerequsite. The relative species of wheat are rich in resistance genes for powdery mildew disease. Understanding the inheritance of these resistance genes is essential for effective use of them. The advent of molecular markers and construction of molecular marker maps of wheat has facilitated the studies of the resistance genes. In this study, genetic analysis of a wild emmer wheat accession 21449 was carried out, and one recessive resistance gene in 21449 was mapped with microsatellite markers.The segregation pattern in the F2 and F3 progenies of the cross between 21449 and 21441 suggested that 21449 contains a recessive resistance gene and a dominant one, resistant to isolate 2Q3-5, and the recessive one is also resistant to the natural population from local fields in Nanjing area. Two hundred and forty eight SSR markers were screened, among which one hundred and seventy nine markers are polymorphic between parents, and six markers are polymorphic between the resistant and susceptible pools. SSR analysis was carried out in the F2 population inoculated with the mixed isolates. The recessive resistance gene in 21449 is linked with Xgwm344, Xcfa2040 and Xwmc525. The linkage relationship was confirmed in three F3 progenies segregating for the recessive gene. One F3 progeny is...