Abstract:Huazhan is a new native restorer line bred in China and widely used in recent years. Its hybrid rice combinations showed good resistance against rice blast. In the present study, 62 blast isolates collected from South China were used for inoculating the restorer lines of Huazhan, Minghui63 and Guanghui998. The inoculation tests revealed that Huazhan was a broad resistant restorer line whose resistance spectrum (RS) was 95.2%. To identify the rice blast resistance gene(s) of Huazhan,we constructed a F2 population derived from Lijiangxintuanheigu (LTH, as a female parent) and Huazhan (as a male parent) for genetic analysis. The blast isolate GD00-193a which had a broad virulence to rice cultivars from South China was used to inoculate all of the F1 and 1 000 F2 individuals of LTH/Huazhan. The genetic assay indicated that Huazhan carried a dominant resis-tance gene, since all of the F1 plants were resistant and the segregation of resistant and susceptible progenies fitted a 3R∶1S ratio in the F2 population. The resistance gene was mapped in the Pi2/Pi9/Pi50 region on chromosome 6 through bulked segregant analysis (BSA) and recessive class analysis (RCA) using 300 microsatellite markers equally distributed on 12 rice chromosomes. The result of further Pi2 alleles sequencing showed that Huazhan carried the Pi2 gene. The present study will provide the basis for the application of Huazhan in hybrid rice breeding and the variety distribution and rotation of its combinations.