Genetic Analysis and Gene Mapping of Rice Blast Resistance in japonica Variety Ziyu 44

The F1,F2,BC1F1 and 276 F7 recombinant inbred lines(RILs) derived from Ziyu 44(a plateau japonica rice variety from Yunnan Province,China,with durable blast resistance) and Jiangnanxiangnuo(a low latitude japonica rice variety,highly susceptible to blast) were obtained to study the inheritance of rice blast resistance.The F1,F2 and BC1F1 were inoculated with blast races ZB13 and ZE1,respectively.Genetic analyses on the three populations of F1,F2 and BC1F1 showed that the rice blast resistance to the races ZB13 and ZE1 were both controlled by a single dominant gene,respectively.Furthermore,a population including 266 F7 RILs from the 276 F7 RILs was used to map the rice blast resistance gene to the race ZE1.The gene was mapped on rice chromosome 11 with a distance of 0 cM to SSR marker RM206 and tentatively designated as Pi-zy(t).These results provide essential information for further utilization of the blast resistance gene in Ziyu 44 in rice disease resistance breeding and positional cloning of the gene.