Genetic Analysis And Fine Mapping Of A Yellow Green Leaf (YGL3) Gene In Rice (Oryza Sativa L.)

Chloroplasts are the site of photosynthesis in plants and other photosynthesizing organisms. Chlorophyll is the most molecule of photosynthesis in chloroplasts, the defective synthesis of chlorophyll is a common mutant type in nature. The color variation of leaf is the outstanding feature. The defective synthesis of chlorophyll is not only to directly reveal the synthesis and metabolism of chlorophyll, but also to explain the development process of chloroplasts and morphogenesis of chloroplasts and other organs which are influenced by environment signal. They all have the important theoretical value and practical significance. In this paper, Jinhui10 has been induced by EMS, in which we have found a yellow mutant ygl3. The morphological character, the dynamic change of chlorophyll content, the florescence dynamic parameter, economical character, the microstructure of chloroplasts, SOD enzyme activity and other parameters have been surveyed and observed. In addition, ygl3 has been located on genetics map. The mainly results as follows:1. The morphological analysis and economical character of ygl3The leaf of ygl3 always expresses yellow in the whole growth. Even in the late growth period, the yellow color does not change to green. Moreover, sheath also show yellow and has normal setting percentage. Other economical character lead to a marked loss in absolute plant and the weight of mainly spikes, which are decreased to 0.43,0.3, respectively,2. The ultrastructure of ygl3 The chloroplast of leaf of wild type in seeding stage has granum thylakoid, which are stacking each other. But granum thylakoid of ygl3 express empty lamellar and also irregular.3. The chlorophyll content and SOD enzyme activity of ygl3The chlorophyll content of ygl3 was decreased significantly, including Chlorophyll a, Chlorophyll b and total chlorophyll. The average of chlorophyll content of ygl3 is 1.09 mg/g in whole growth, which are significantly decreased in 3.26mg/g of wild type. However, SOD enzyme activity has increased significantly.4. Genetic analysis of ygl3Two maintenance line and ygl3 and one sterile line have reciprocal crossed, the five association of F1 are always showing green, which illustrated the gene are controlled by recessive nuclear gene. The results of F2 shows that the proportion of green and yellow is 3 to 1, which demonstrated the gene is controlled by a pair of gene. Therefore, the character of yellow leaf is controlled by a pair of recessive nuclear gene.5. Fine mapping of YGL3The gene of YGL3 is mapped on the long arm of chromosome 3, which are located between SSR marker SWU3-1 and SWU3-2, the period of 101Kb.6. Analysis of predicted genesMagnesium-chelatase subunit ch1D is highly correlated with ygl3 phenotype. However, whether the gene has encoded rhe gene of magnesium-chelatase subunit ch1D or other genes that have not been discovered necessarily need to make further location and complenentary verification with other relative genes.