[Analysis of heading time genotype for a rice photoperiod and thermo--sensitive male sterile line PeiAi64S].

PeiAi64S,a photoperiod and thermo - sensitive genic male sterile,has been wildly applied to hybrid rice seed production in China,but its photoperiod-sensitivity gene for heading date in this sterile line was still unknown.This definitely limited the further use of this sterile line in breeding practice and re-production of hybrid seeds.To solve this problem,using heading time nearly isogenic lines EG0～EG7、ER～LR、T65～T65m and six heading date QTL-isogenic lines,NIL (Hd1) ～NIL (Hd6) with the genes of Nipponbare but Hd1 ～ Hd6 genes from Kasalath respectively,we performed a genetic analysis of PeiAi64S with special reference to photoperiod-sensitivity loci,in natural long days at Nanjing(32° N) where the average day-length is about 14 h and in natural short days at Linshui county,Hainan province(18° 29′N),where the average day-length is about 11.6 h during the course of rice growing respectively.The F_1 and F_2 generations from the crosses ‘PeiAi64S×heading time nearly isogenic lines’ were subjected to genetic analyses.Experimental results showed that PeiAi64S carries photoperiod-sensitivity allele gene E_1 and E_3 and dominant earliness gene Ef-1 in E_1 and E_3 and Ef-1 loci,respectively,and a photoperiod insensitivity allele Se-1~e in Se-1 locus.Meanwhile,the photoperiod-sensitivity gene E_1 and photoperiod-insensitivity gene Se-1~e in PeiAi64S were also identified by crossing with the NIL(Hd1)and NIL(Hd4).In addition,a recessive inhibitor for photoperiod-sensitive gene E_1 or Se-1~n and other modified photoperiod-sensitive genes: i-Se-1,E_3,Hd3(En-Se-1),Hd5 and Hd6,were identified in PeiAi64S by crossing with QTL nearly isogenic lines: NIL(Hd2),NIL(Hd3),NIL(Hd5)and NIL(Hd6),The results indicated that the genotype of PeiAi64S’s heading date was: E_1E_1e_2e_2E_3E_3Se-1~eSe-1~eEf-1Ef-1 i-Se-1 i-Se-1.