Genetic Analysis And QTL Maping Of The Contents For Protein In Rice Seed

Rice is one of the major staple cereal foods, feeding more than half of the world population and it provides the major protein source for the people. Therefore, the enhancement of rice protein content (RPC) has become one of the main objectives in rice breeding for nutritional quality. Rice quality is always a major factor in rice market and has become more and more important as the developed economic status. So the improvement of the rice protein content, protein proportion, and high quality rice is the one of the important research direction in rice breeding.This research has analysized the genetic variation and correlation coefficient QTL mapping of protein content in rice seed and improtant agronomic basing on RIL population including 200 individuals derived from a cross between two japonica cultivars"Bendishuidao X Liaoyou518". The results were summaried as follows.Rice protein content and the improtant agronomic were continuously distributed as almost normally in RIL, which were quantitative traits controlled by multiple genes.There were positive extremely significant correlations between culm length and panicle length, panicle length and effective panicles perplant in RILs. However, the positive correlation between culm length and effective panicles perplant was not obvious to the significant researched level.A molecular linkage map of 85 SSR markers was constructed by using interval mapping, and covered a total length of 1160.95 cM with an average distance of 13.64 cM between adjacent markers in rice genome.Three QTLs related to protein content in rice seed were detected by using composite interval mapping. These located on chromosome 1, 3, 9, which explained 9.87%-13.82% of observed phenotypic variation, and the LOD variation is 1.57-2.20. One QTL for culm length was located on chromosome 2, which explained 6.40% of observed phenotypic variation. Five QTLs for panicle length were located on chromosome 3, 7, 9, 10, 11, which explained 3.94%-8.27% of observed phenotypic variation. Six QTLs for effective panicle perplant were located on chromosome 2, 3, 6, 11, which explained 2.74%-37.94% of observed phenotypic variation. The QTL qCL1 was mapped in the interval RM3740-RM3604 on chromosome 1, the positive allele was from the parent"Liaoyou518". The QTL qPL3 for PL was mapped in the interval RM1350-RM6987 on chromosome 3. The QTL qPL9 was mapped in the interval RM160-RM215 on chromosome 9, and the positive alleles were from the parent"Liaoyou518". The other QTL positive alleles were inherited from the parent"Bendishuidao". Six QTLs positive alleles for EPP were all inherited from the parent"Bendishuidao".Through the stability study of the different fertilizer conditions of rice protein content, the protein content of the Bendishuidao and Liaoyou51 have been improved 5.1%, 9.5%, 21.3% and 9.1%, 16.4%, 20.7% expectively by treating with the methods 2, 3, 4. Tht results showed that protein content of Bendishuidao and Liaoyou518 was increased as the nitrogen fertilization addation.