Study On Genetic Polymorphism Of Cytoplasmic Male Sterility Line Rice

The cultivated rice (Oryza sativa L.) is one of the most important crop in the world, and development of hybrid rice is the most important way to ensure Chinese foodstuff security.Three-line method of hybrid rice breeding have got great achievements and it made rice production increase very fast. The Three-line method of hybrid rice includes cytoplasmic male sterility(CMS) line,male sterility maintenance line and restore line. Cytoplasmic male sterility line is the most important department in development of hybrid rice,but with restrictiong of cytoplasm resource,increase of rice production is hard to achieve,and simplex resource of cytoplasm has potential danger on rice rice industru.So,it is necessary to research on genetic polymorphism in CMS line and has benefits on yield and security of rice production.The main content of this study is about genetic similitude of nuclear genome and polymorphism of chloroplast(CP) DNA in CMS line.The mosty results of experiments:1. Genetic similitude of nuclear genome in CMS line:SSR(Simple Sequence Repeat Polymorphisms) was used in genetic similitude of nuclear genome.33 pairs of SSR primers have good quality in PCR reaction,there had overall 130 bands,69 bands were polymorphism bands.In the 33 primers,only 7 primers had no polymorphism bands.After analysed with PCR reaction outcome,we got the genetic similitude and clustering map.It is clear that CMS line has abundant polymorphism in genome. Yuetai A,Gang46A and GuangyeA have far distance on genome comparabilityJin23A and Zhong9A have the least distance on genome comparability .Residuary rice material have higher comparability in the research.2. Polymorphism fragments of chloroplast(cp) DNA in rice materials, the rice maerials are 11 kinds of CMS line rice,5 kinds of indica rice,4 kinds of japonica rice and 5 kinds of common wild rice(CWR). ORF100 and ORF29-TrnC^GCA are 2 molecule marks of indica and japonica type cpDNA with fragment length polymorphism.After analysis of all rice materials with the 2 molecule marks,we find that 11 kinds of CMS line rice,5 kinds of indica rice and Dongxiang CWR Hepu CWR have indica type cpDNA; 4 kinds of japonica rice and Hainan CWR,Fushui CWR,Chaling CWR have japonica type cpDNA.Rps16 and TrnT^UGU-TrnL^UAA are 2 polymorphism fragments with DNA sequence in cpDNA.After analysis on the 2 fragments,we can see all CMS line rice have the same sequence in the 2 fragments except YuetaiA.. Cultivated rice have abundant base polymorphism in the 2 framents.There is 0.66% base location polymorphism in indica rice,and 0.26% in japonica rice, 1.66% between indica and japonica rice. Base location polymorphism between subspecies is higher than in it. CWR have some polymorphism in the 2 polymorphism fragments,there is 0.59 % base location polymorphism.It showed that the CMS cytoplasmates were singularity. CMS line materials have lower polymorphism than indica,japonica and CWR. Simplex cytoplamate has conjuncture in rice production, just like disease of rice. The development of New type Three-line method of hybrid rice is mightiness safeguard in this instance. And it is a good way to solve the problem on security of rice production.