Fine Mapping Of A New Resistance Gene Xa32(t) For Bacterial Blight (Xanthomonas Oryzae Pv. Oryzae) In Rice

Rice(Oryza. sativa)is one of the most important crops,playing an improtant role in the global food production. Bacterial blight caused by Xanthomonas oryzae pv. oryzae is One of the most serious diseases in rice production all over the world. It can reduce the rice plant by 20%-30%, even no crop. Recently,chemical prevention and control and planting resistant cultivar are used to avoiding the diseases.But,the first way have little effect and can damage the environment. Planting resistant cultivar are proved the most effective and environment-friendly strategies for preventing the disease.The rice germplasm C4064 was proved harbored a new bacterial blight resistant gene, designated as Xa32(t).Chongke Zheng studied on it systematically,and the gene was mapped within a length of 2.0cM on the long arm of rice chromosome 11.Based on the front study, this study engages on fine mapping the gene, the results are as follows:1,Comparison of resistance spectrum:Through comparison of resistance spectrum with all known bacterial blight resistance genes and genetic analysis,the C4064 was proved to contain a new bacterial blight resistant gene.And the front study was proved to be true.2,Fine mapping of the new gene Xa32(t):To fine map Xa32(t) gene, Bulked Segregant Analysis (BSA) was adopted to survey SSR and CAPS molecular markers. By analyzing five F4 populations,threeF5 populations and two F6 populations,with seven molecular markers.the gene Xa32(t) was fine mapped within a length of 0.14cM on the long arm of rice chromosome 11, with a physical distance about 113 Kb.3,Identification of separation offspring of exchange plants:The results is that all the plant is susceptive. 4,Near-isogenic line construction:By cross and backcross means, gene Xa32(t) was introgressed into the susceptible variety JG30(Jingang 30).And the near-isogenic lines have been obtained BC6F1 generation.