Location Of QTL For Wheat Sharp Eyespot Resistance And Genetic Diversity Studyed Of Chinese Winter And Spring Wheat Varieties

The improvement of sharp eyespot resistance is very difficult through the traditional breeding methods. Molecular marker technologies provide powerful tools to identify the genes controlling the quantitative traits. QTL and associated markers for agronomic traits, physiological traits, disease and pest resistance have been studied for marker-assisted selection(MAS), but there are few reports on sharp eyespot. In this paper, location of QTL for wheat sharp eyespot resistance in ITMI RIL(Recombined inbred lines) population was studied.On the other hands, this paper explored the relationship and genetic diversity of winter and spring wheat varieties in China. One hundred and forty-one microsatellite markers located on 21 chromosomes of wheat were applied to investigate the genetic diversity among 73 Chinese winter and spring wheat varieties(Triticum aestivum L.).The main results as follow:1.The major QTL for wheat sharp eyespot resistance were detected with the composite interval mapping(CIM), three mapped in chromosome 2D with the phenotypic varience of 14.36%, 12.94% and 14.14%, one in chromosome 6A with the phenotypic varience of 16.80% and one in chromosome 7A with the phenotypic varience of 17.52% explained in ITMI RILs. QTL in chromosome 2D were detected both in field and greenhouse environments, which have high stability.2. Four major QTL for cold stress were detected. They are mapped in chromosomes 1B, 3D, 5D, 6A respectively. QTL in chromosome 6A can be detected in two repeats, and its interval covered the interval of the QTL for sharp eyespot resistance. It infers that there are some associations between sharp eyespot resistance and cold stress. 3. One hundred and forty-one microsatellite markers located on 21 chromosomes of wheat were applied to investigate the genetic diversity among 73 Chinese winter and spring wheat varieties(Triticum aestivum L.). A total of 513 alleles had been identified in these varieties. Each pair of primers could detect 2 to 10 alleles with an average of 3.61. The mean polymorphism information content(PIC) was 0.60, varying from 0.08 to 0.88. Based on cluster analysis, the 73 wheat varieties could be clustered into 4 groups, which generally agreed with pedigree analysis. Diversity analysis showed that the PIC values of homelogous group 5 was higher, and homelogous groups 4 and 6 were lower.