Genetic Analysis And Mapping Restorer Gene Of A Novel Cytoplasmic Male Sterile In Rice

The breeding of hybrid rice has solved the grain issue in the world,which is based on the successfil application of cytoplasmic male sterility and fertility restoration in rice.In this paper,a new type of cytoplasmic male sterility and its fertility restorer gene were studied,which has laid a theoretical foundation for the development of new hybrid cultivars.Having observed the basic characters of the sterile gene,we found that the sterile anther was distorted,and the shape of the pollen grain was irregular,with no inclusions showing unstainable in the I₂-KI solution and the whole plant being weak.As different types of hybrid offspring separation ratio were investigated respectively,the proportion of fertile and sterile phenotype was 3.19:1 and 3.06:1,?²=1.98<6.64??² 0.01 1?.This is consistent with the proportion of 3 to 1 in Mendel's genetic laws.Therefore,it is concluded that the cytoplasmic male sterile gene belongs to the sporophyte,and the restorer gene is a single dominant gene.Using molecular markers to map this restorer gene precisely,we revealed that this gene was located in a region about 49Kb between WID61 and CAP53-Fok I.Searching for the sequence annotation of the positioning interval,we demonstrated that there were 2 candidate genes related to fertility restoration,namely Cgl and Cg2 respectively.By sequencing and analyzing the sequences of restorer line and male sterile line,we infer that Cg2 is the target fertility restorer gene,while the final determination of the target gene still requires a series of experiments.