Genetic Anlysis And Gene Mapping Of A Yellow-Green Leaf Mutant5941ys In Rice

The leaf color mutants are very important materials for plant physiology and fuctional genomics research, at the same time the leaf color mutants can as marker traits and germplasm resources in corp breeding. In this study, we use ethyl methane sulphonate(EMS) Mutation of the Indica rice G46B, we found a stable genetic yellow-green mutant in the offspring of the mutants and designated it as5941ys. We reasearched morphological charateristics, physiology charateristics, main agronomic of the mutants. We had genetic analysis with the F1and F2generation of the5941ys/Nipponbare and Nipponbare/5941ys.while use the5941ys/Nipponbare F2and Molecular markers for gene mapping the target gene. All we have done a funcation of the target gene clone and clarity the molecular mechanism of the5941ys leaf color mutant.Phenotype characteristics and argonomic traits of the mutant5941ys:The5941ys mutant plant yellow-green leaf throughout the whole growth period,and can heading. Compare with wild type, the5941ys mutant plant growth potential was weaker. Except seed setting rate has no different with the G46B,the other agronomic traits of the mutant significantly decreased. Plant height decreased37.9%,number of productive panicles per plant decreased44.4%,panicel length decreased17.6%,1000-grains decreased15.8%,and number of spikelets per panicel decreased the most as55.4%.It indicated that the leaf color mutant can impact the yield.The contents of chorophyll and carotenoid in the mutant5941ys:Compared with wild type, the content of photosynthetic pigments in the5941ys mutant plant leaves at seedling stage was significantly decreased, the total chlorophyll content of5941ys decreased36.6%, carotenoid content of5941ys decreased8.2%,chlorophyll a content of5941ys decreased34.7%, chlorophyll b content of5941ysdecreased44.0%, but chlorophyll a/b increased. This showed that carotenoid decreased less than chlorophyll,chlorophyll b decreased more than chlorophyll a.The electron microscopy structure of the mutant5941ys choroplast:Compared with wild type, the mutant5941ys choroplast was long and thin, choroplast inside was fuzzy, the thylakoid developing abnormal, grand reduced, and grana thylakoid reduced, most shape as lines.Even some choroplast has vesicles, and couldn’t see the grana. It indicated that the mutant5941ys choroplast developing was inhibited.The genetic analysis of of the mutant5941ys:Reciprocal cross the5941ys mutant with Nipponbare, by analysing the reciprocal cross Fi and the5941ys/Nipponbare F2,the result suggested that the yellow-Green trait of the5941ys mutant was controlled by one pair of recessive nuclear.The gene mapping of the mutant5941ys:Using the F2population of5941ys/Nipponbare as the mapping population and the SSR marker has parental ploymorphism between5941ys and Nipponbare,we mapping the target gene on the2chromosome in the region betwen RM262and RM263,with a genetic distance of13.3cM and10.2cM, respectively. We use the rice genome data design some Indel markers in the region betwen RM262and RM263.Use the Indel marker has parental ploymorphism,we finally map the target gene betwen YS-1andYS-2, with a genetic distance of0.087cM and0.26cM,respectively, and the physical distance was263kb.So we infer that the target gene is a new leaf color gene, and named it as5941ys(t).