Genetic Research And Molecular Mapping Of Stripe Rust Resistance Gene In Wheat Line L693

The wheat (Triticuma Aestivum L.) is one of the most important crop in the world. Stripe rust is one of the most destructive wheat (Triticum aestivum) diseases in the world. The application of resistance varieties is a most effective and economical method for the disease control. The material basis of resistant varieties is resistance gene resource, so created new resistant material and explored new resistance gene are ongoing and important daunting tasks. Thinopyrum intermedium is important outer edge resources.In this study, MY11was used as a female parent to hybridize with YU25which derived from Thinopyrum intermedium. Two sister lines choosed from their high-generation lines:resistance to stripe rust L693and susceptible to stripe rust L661. Two F2populations derived from the crosses L661/L693and L693/L661were employed to analyise the resistance inheritance and to determine the chromsomeal loacation of the resistance gene in L693. The results obtained are as follows:1. The identification of resistance to pedigree, the resistance gene to wheat stripe rust had transtered a new strain of wheat line L693from exogenous.2. The infection types on L661and L693to six Chinese races of Puccinia striiformis f. sp. tritici (Pst). Results show that in the case of control material SY95-71showed highly susceptible to stripe rust, L661showed highly susceptible to stripe rust and L693showed a strong resistance to six Chinese races of Puccinia striiformis f. sp. tritici (Pst).3.The two F1populations, derived from the crosses L661/L693and L693/L661, are resistant to stripe rust. The resistance segregation comply with the the theoretical ratio of3resistant (R):1susceptible (S) in the two F2populations. Moreover, the genotypes tested by the F2:3families in two F2populations was also with the theoretical ratio of1R:2Hetergenerous (H):IS, which shows that the stripe rust resistance gene in L693is controlled by a domiant gene.4. With SSR molecular marker, two sets of Xgwm and Xwmc wheat SSR markers were used to analyze the polymorphisms among polymorphic primers L661, L693and F2population of L661/L693and L693/L661. The results show that:Xbarc137-1B, Xgwm273-1B, Xbarcl87-1B, Xgwm18-1B, Xgwm11-1B and Xwmc269-1B were linked to the stripe rust resistance gene in L693, which was a new stripe rust resistance gene on the wheat1B chromosome and temporary designated as YrYU25. Each marker genotypes for resistance to stripe rust reaction and molecular genotype trajectory were in accord with the theoretical ratio of1:2:1. Xbarc137-1B, Xgwm273-1B and Xwmc269-1B were linked to YrYU25. The genetic distances of YrYU25to the primers were0.127cM,0.084cM and0.97cM, respectively. The primers Xbarc187-1B, Xgwml8-1B, Xgwm11-1B were co-segregate with the resistance gene YrYU25to stripe rust.5. In order to increase the marker density genetic linkage map, use bioinformatics and wheat genome draft to redesign primers, and analyze the polymorphisms among polymorphic primers L661, L693and F2population of L661/L693and L693/L661. There are three markers were linked to YrYU25. Xwmc626-1B-1and Xcfd65-1B-1were linked to YrYU25. The genetic distances of YrYU25to the primers were0.067cM and0.864cM. Most importantly, the primers Xbarc187-1B-1was co-segregate with the resistance gene YrYU25to stripe rust.6. The PCR products of the nine microsatellite markers linked to the stripe rust resistance gene in L693in nulli-tetrasomic (1B) show that the specific bands can be amplified in N1AT1B N1AT1D, N1DT1A, N1DT1B, but no PCR products in N1BT1A and N1BT1D. This further supported the conclusion that the stripe rust resistance gene in L693wase on the wheat chromosome IB and temporary designated as YrYU25.