SSR Makers Of Cytoplasmic Male Sterile Restorer Gene In Soybean

Soybean is an important grain and oil crop, also it is an important industrial rawmaterials. Domestic demand for soybeans increased year by year, but the production ofsoybean was grown slowly. To increasing the production of soybean, that the only way is toimprove the unit output. And useing heterosis is one important way to diging latent capacityand improving the production of soybean.The discovery of cytoplasmic male sterile cytoplasm in soybean and the utilization ofsoybean hybrids are the breakthrough developments. Cytoplasmic male sterility"three–lines” are the basic materials for soybean hybrid breeding. Breeding for strong restorer linesis very complicated and restoring ability can only be identified by testcross with malesterile lines, which is time-consuming and labor-intensive.Through screening makers linkedwith restore gene closely by DNA molecular maker technology, we can accurately locaterestore genes. Molecular assisted breeding can shorten the breeding time, and it also lay thefoundation for studing molecular mechanism of fertility restoration and eventually cloningof restorer gene. Therefore, carried out the research of cytoplasmic male sterility restoregenes location has important significance.F2segregating population, which was obtained by crossing between the gametophytegenetically RN-cytoplasmic male sterile line and backcrossing lines with strong restorergene.Then it will be used for the Rf gene mapping through determination of the inheritancepattern by sterility identification of each generation and further polymorphism analysis byhigh density of SSR markers and fine mapping of the restorer gene.Firstly，the RN type soybean cytoplasm sterile lines9A cross with strong restorer linesJLR2to get F2segregating population. According to the results of microscope detection, theF1is semi-sterility, ratio of fertile to semi–sterility in F2separation population is1:1.Theresults of this study show that RN type soybean cytoplasmic male sterile lines is controlledby single gene gametophyte sterility.Gene pools from F2segregating population was screened with200SSR primers, andSctt011showed polymorphism among the three gene pools, which was located in J linkagegroups. Then,93additional SSR primers from J linkage groups were chosen to screen genepolls. Finally, three primers are linked with restorer gene which are JS22，JS30and JS51, and the genetic distances are7.6cM,10.7cM and5.2cM,respectively.The restorer genewas located in J linkage groups.The linked markers with restorer gene identified in this study will accelerate thebreeding process of RN-restorer lines, and lay the foundation for Rf gene cloning andRN-CMS fertility restoration mechanism exploration in future.