Molecular Marker Localization Of Powdery Mildew Resistance Gene In Shannong 10103 And Identification Of Germplasm Line

Wheat is one of the most important food crops in the world. Improving wheat production continuously is very important to ensure world food safety. Development of exotic wheat germplasm with abundant genetic variation can contribute to wheat breeding. In this study, the hereditary character of the gene with resistance to powdery mildew in germplasm lines Shannong10103 was analyzed and the resistance gene was mapped by molecular markers; In addition, 28 germplasm lines were also characterized by combining morphological, cytological, biochemical and molecular biological methods. The main results were summarized as below:(1) To identify the genetic characteristic of the powdery mildew resistance gene in wheat germplasm Shannong10103, a F2 segregation population derived from the cross Shannong10103/Huixianhong was created and screened by molecular marker. The results showed that Shannong10103 and Shannong10103/Huixianhong F1 were resistant to powdery mildew at seedling stage, the segregation ratio of resistant:susceptible plants in F2 population was 3:1, suggesting that the powdery mildew resistance gene in Shannong10103 is controlled by a single dominant gene, and was named as PML10103. Screening of 2606 pairs of SSR, EST-SSR and STS primers for polymorphism in the parents and preferred group obtained seven SSR, EST-SSR markers(Xcinau188, XCAU127, CFE164, CWM109, SWES231, Xcnl113 and SWES1015) that were linked to PML10103. The genetic distance between the resistance gene and the markers Xcinau188, XCAU127, CFE164, CWM109, SWES231, Xcnl113 and SWES1015 were 0.4cM, 0.7cM, 4.8cM, 3.0cM, 4.9cM, 3.3cM and 0.9cM, respectively. A molecular marker genetic linkage map of was constructed and PML10103 was mapped on wheat chromosome 6B.(2) 28 Triticale and Triticum aestivum germplasm lines were characterized by methods of morphology, cytology, biochemistry and molecular biology for main agronomic and cytological characteristics. Data collected from field experiments indicated that the 28 germplasm lines had excellent agronomic characters. Among them, 6 Triticale germplasm lines contain rye genetic material and 16 Triticum aestivum germplasm lines contain the Haynaldia genetic material. These lines were fructuous and floriferous, highly resistant to powdery and stripe rust, which could be used as parents lines to make crosses in breeding. The germplasm lines obtained in this study enriched the germplasm resources for wheat breeding and provided useful information for the genetic improvement of wheat cultivars.