The Genetic Analysis And Fine Mapping Of The Major Restorer Gene Of 'D' Type Hybrid Rice Restorer Line

Hybrid rice has played an important role in grain production in china Cytoplasmic male sterility (CMS) is the commonly used system in hybrid rice breeding. D type CMS line is widly used in China. Information on the fertility restoration and chromosome locations of restorer gene in this CMS system can facilitate breeding restorer lines by marker -assisted selection and map-based cloning of restorer gene.This stuy foucused on the genetic analysis and fine mapping of the major restorer gene of 'D'type hybrid rice restorer line.The main results are summarized as blow:1.Isolation of major Quantitive Trait locus (QTL) of restorer gene To isolation the major Quantitive Trait locus (QTL) of restorer gene we used a set of near-isogenic lines (NILs) of D297 carrying genotype for fertility restoration from Minghui63 By application of marker-assisted selection, back-cross and self-cross segregation ratio investigation,we chosed NIL 818 which contains the major restorer gene and has similar genetic background to "D297A" (the polymorphism ratio is 1.5%). Moreover,the fertility segregation ratio of F2 population of 818/D62A and 818/zhengshan A is coincidenced to 3:1.2.Genetic analysis of the major restorer geneThe pollen fertility and self-cross seeding ratio of 818/D62A,818/D297A,818/zhengshanA (respectively planted in Hainan and Wenjiang),minghui 63/D62A,minghui 63/D297A,minghui 62/zhengshan A were compared.The results indicated that difference of the fertility restoration ability between the single major restorer gene and all restorer genes of minghui 63 is very small ,and the expression of the major restorer gene can not be affected by genetic background and ecological variances.3 .The cytological characterization in fertile and sterile pollenThe results show that the pollen of D297A is abortive at the later stage of uninucleate whichmainly take place at tapetum.The single major restorer gene.in NIL 818 can completely restore the fertility of pollen of D297A.4.Fine mapping of the major restorer geneBy application of SSR,Caps,RFLP, we constructed the fine genetic map of the major restorer gene ,and the distance between the restorer gene and moleculer marker RM258,RM304,S-10,RM228 is respectively 3.9 cM,1.1cM,0.7cM,14.5cM .5. The physical map of the major restorer gene and its draft sequenceBy means of electronic hybrid, the genetic map and physical map of the major restorer gene were intergrated,then we utilized the rice genome scequence applied by sygenta,RGP and Huada genome center to finish the draft scequence of physical map. The annotation of scequence was also performed.