Abstract:Abstract: Kangfeng A is a new CMS Line with special nuclear genetic background, which was from a new variant germplasm successive backcross with a CMS-wild abortive (WA).The new variant germplasm, with normal cytoplasm, male fertile and no restoring ability, which was from a cross between an indica-japonica restorer line 97gk419 with wide compatible gene and an indica restorer line Minghui 70(Restorer line×Restorer line).In this study, the evaluation of Kangfeng A for its resistance against 53 Magnaporthe grisea strains collected from different rice cultivated regions showed that Kangfeng A had the broad-spectrum performance for blast resistance in South China rice regions, especially in Fujian. The genetic analysis of Kangfeng A showed that the blast resistance was controlled by one dominant gene, which was evaluated by inoculating F1and F2 populations derived from a cross of Kangfeng A(B)×LTH with four Magnaporthe grisea strains, 81278,Guy11,FJ2009-66 and 98013A. The allelic test indicated that the resistance gene in Kangfeng A to strain 81278 was non-allelic to known loci (Pi-1,Pi-2,Pi-ta and Pi-3 ), and was genetic linkage to Pi-ta(Pi-?), then tentatively designated Pi-kf1(t).