Genetic Analysis And Gene Mapping Of A Lemma-like Sterile Lemma (lsl) Mutant In Rice (Oryza Sativa L.)

Rice(Oryza sativa L) is a kind of economic crops, whose development degree of the flower/spikelet will directly affect the quality of rice paddy and corn production. Futhermore, as the model plant for study of molecular developmental biology in monocots, research of rice floral/ear development is more widely. As the typical gramineae inflorescence of peculiar structure, rice spikelet is an important trait related with grain weight, where to reproductive growth. Generally, in-depth study of spikelet development, not only can help to understand the molecular mechanisms of rice floral/spikelet development, also help to rich knowledge of plant developmental biology, respects and increase corn production has a great value.In this study, a sterile lemma mutant lsl (lemma-like sterile lemma) with significantly lemma-like, which is derived from ethyl methane sulfonate (EMS)-treated mutation in maintainer rice Xinong 1B. The mutant sterile lemma elongation and widen, serious silicide surface cells, with a large number of burr, and lemma is similar to the morphological structure. Now, systematic studies for the lsl will be done, including morphological characters, content of photosynthetic pigments, microscopic observation, genetic analysis and gene mapping of the LSL gene. The main results were as follows:1. Phenotypic identification of lslSterile lemma lemma mutants were found in EMS mutagenesis library. Compared with wild type LSL mutant sterile lemma developmental abnormalities under field planting conditions, according to the statistical data analysis showed that the length of the LSL mutant sterile lemma significantly greater than the wild type, sterile lemma width is significantly more than the wild type, morphological characteristics similar to lemma. In the event of a sterile lemma elongation of wider phenomenon at the same time, rice kernels theoretically should be increased, but according to the statistical data show that LSL mutant showed significantly lower grain. The weight of the sterile lemma mutant of 24.7%, is sterile lemma wild-type thousand grain weight of more than 6 times, so after the minus the sterile lemma, mutant grain compared with wild type performance significantly lower, suggesting that the LSL mutation has seriously affect rice yield.2. Cytological analyses of IslTo further reveal the LSL mutant sterile lemma lemma traits, combining with scanning electron microscope (SEM) analysis, compared with wild type sterile lemma smooth surface cells less flat, burr and random distribution. Serious silicide and mutant sterile lemma surface cells are arranged close gaps structure, size and number of burr significantly more than the wild type, the structure characteristics and performance at the same time period the surface structure of lemma. At the same time, through paraffin section observation found that wild-type spikelet sterile lemma is mainly composed of upper and lower surface cells and parenchyma cells in the middle of the three layers, and not silicide on the skin. Mutant of spikelet sterile lemma is composed of four layer cells:the table includes silicide on the skin Thick-walled cells layer thin wall layer and swollen lower epidermis cells. The cells within the organizational structure with the wild type and mutant lemma is consistent, integrated these phenotypic results show that the LSL mutant sterile lemma appeared to lemma of homologous alien.3. Genetic analyses of lslJinhui10 was crossed with the lsl heterozygote for for genetic analysis, which the F1 populations derived from. All the F1 generation were normal and no elongation phenotype, sterile lemma of F2 populations appear separation between individual, elongation and normal sterile lemma two cases, the normal strain 1505 strains, elongation 481 strains, the segregation was 3:1 through the test of χ2 in F2 population(χ2=0.8868<χ2 0.05=3.84). The results fully suggested that a single recessive gene controlled the sterile lemma mutant phenotype.4. Mapping of lsl locusThe polymorphisms between the lsl and Jinhui 10 were screened with 400 pairs of SSR primers. The results showed that the linkage relation between mutant locus and markers RM6057, RM5531 within the lsl locus were located between markers RM6047 and RM2381 on the short arm of chromosome 7. Then 62 pairs of SSR primers in the proximal region of the lsl locus between RM6047 and RM2381 were used for mapping, the LSL gene was mapped between markers RM1085 and RM6663 on the short arm of chromosome 7, at distances of 0.78cM and 0.12cM, respectively and the physical distance is 735.5Kb.