Genetic Analysis And Gene Mapping Of Two Mutants In Rice (oryza Sativa L.), Long Glumes Mutant And Narrow Leaf Mutant

The research on floral organ is always hot to plant molecular biologists. The studies on long empty glumes mutant may further elucidate additionally that the molecular mechanism of rice floral development. Ideal plant type is the base of hybrid rice with high yield. As one kind of leaf shape, narrow leaf plays an important role in building the ideal plant type of rice.In this study, we obtained a long empty glumes mutant, provisionally named Osleg, from the cultivar called'Yaxuenuo'. Several abnormal morphological characteristics, including two long empty glumes longer than the fruit, slower seed-germinating, later growth period were observed. Using scanning electron micrograph, we observed that the abaxial surface of the mutant Osleg is rough, formed some trichomes, arranged in some tubercles in parallel, which is very similar to the lemma of the mutant and contrast. We also discovered narrow leaf mutant, provisionally named nal, from the EMS mutant library in rice. Through the observation, the mutant was very dwarf with highly inward rolling leaves. At the heading stage, the chlorophyll content detected by the portable chlorophyll testing system showed that the content of chlorophyll in the flag leaf of mutant reduced compared with the contrast.To mapping the two mutant traits, we constructed F2 and F3 populations by crossing between the two mutants and 9311 respectively for phenotype analysis, genetic analysis and gene location. The results listed as follows:1. To map the OsLEG gene, F2 population was constructed by a cross between Osleg and 9311. A total of 1485 long empty glumes plants and 4302 normal plants were observed in F2 population fitting for the 3:1 segregation ratio through the chi-square test. The result of genetic analysis indicated that the mutation was controlled by a single recessive gene. Some published SSR markers were used to map the OsLEG gene on the on the short arm of chromosome7 between RM3222 and RM3225. To fine-map the OsLEG gene, we designed some STS markers. Ultimately, the OsLEG gene was located on the short arm of chromosome7 between LC15 and LC25 in a 207kb region. These results provided the foundation for the further cloning the OsLEG gene and study on the molecular mechanism of floral development in monocot.2. Genetic analysis showed that the mutant character was controlled by a single ressesive gene based on the field observations on a F2 population crossed between nal and 9311. A total of 500 narrow leaf mutants from the F2 population were selected to map the mutable gene. 533 pairs SSR markers, which distributed on 12 chromosomes equably, were used to screen the polymorphism between the two parents. 233 pairs of them were polymorphic markers with the polymorphism rate of 41.8%.