Studies On SSR Molecular Marker Of Wheat Powdery Mildew Resistance Genes Pm2 And Pm5e

Powdery mildew, caused by Erysiphe graminis f.sp tritici, is a destructive disease of common wheat throughout the world. Breeding and popularizing resistance cultivars has been proved the most effective, economical and environmentally safe method to suppress the pathogen. However, the resistance cultivars containing single Pm gene often loss the resistance because of the pressure from the powdery mildew pathogen's dissociation. So breeding pyramiding cultivars containing more Pm genes using the molecular MAS strategy, including Pm gene's marking and location is an urgent task.1. Pm2 has been proven to be an effective resistant gene in common wheat, conferring high resistance or immunity to most of Erysiphe graminis DM f. sp. Tritici isolates. NILs (near-isogonics lines) with Pm2, its recurrent parent Chancellor and their F2 segregation population were used to identify SSR (Simple Sequence Repeats) marker by using 71 microsatellite primers originally assigned to chromosome 5D of wheat and BSA (Bulked Segregant Analysis) method. The polymorphisms were revealed by 12 of 71 SSR primers between the two parents, and the peculiar DNA bands (Xcfd189360, Xcfd29190, Xcfd8160, Xcfd102250, Xcfd7200, Xcfd57245 and Xgwm190210) were stable amplified by 7 of 12 SSR primers between the resistant and susceptible DNA pools, the resistant and susceptible plants of F2 population respectively. Among them, Xcfd189360 was shown to co-segregate with the gene Pm2, and Xcfd29190, Xcfd8160 and Xcfd102250 were relatively close to Pm2 with a linkage distance of 1.5cM, 2.3cM and 3.9cM, respectively. and these markers can be used for MAS (Marker-Assisted Selection) in wheat resistance breeding procedure for the identification or pyramiding of Pm2 with other resistance genes.2. Pm5e (Fu Zhuang 30) has been proven to be an effective resistant gene in common wheat, conferring high resistance or immunity to most of Erysiphe graminis DM f. sp. Tritici isolates. with Fu Zhuang 30, its recurrent parent Chancellor and their F2 segregation population were used to identify SSR (Simple Sequence Repeats) marker by using 56 microsatellite primers originally assigned to chromosome 7B of wheat and BSA (Bulked Segregant Analysis) method. The polymorphisms were revealed by 8 of 56 SSR primers between the two parents, and the peculiar DNA bands (Xwmc364175,Barc06590 and Xwmc517200) were stable amplified by 3 of 8 SSR primers between the resistant and susceptible DNA pools, the resistant and susceptible plants of F2 population respectively. Among them, Xwmc364175 and Barc06590 were relatively close to Pm5e with a linkage distance of 4.9cM and 5.1cM, respectively. and these markers can be used for MAS (Marker-Assisted Selection) in wheat resistance breeding procedure for the identification or pyramiding of Pm5e with other resistance genes.