Screening,Genetic Analysis And Improvement Of Long-storability In Rice (Oryza Sativa L.)

Long-storability rice usually have good favor and high vigor for a long storage. Rice storability affects the regeneration cycle of accesions stored in geneback, the seed sowing amount and seedling establishment in the rice production, and the risk of commercial production and management of hybride seeds. In this study artificial ageing was used, and more than 1200 rice varieties were screened for long-storability. The characteristic of storability was identified in 127 DH lines, which was derivered from ZYQ8 and JX17, and quantitative trait loci (QTLs) for long-storability was analysed. The long-storability rice and Lox-3 lacking mutant were used for rice storability improvement. The main results were given as following:1. The storability of 56 rice conventional varieties were investigated for ageing index underartificial ageing and natural ageing, and the results indicate that the correlation coefficient among them were highly significant. There is no relationship between seed dormancy and seed storabilty. Artificial ageing maybe is a good method in the study of long-storability.2. The Lox-3 lacking mutant and other three conventional varieties, Zhe 733, Xiushui 11, and KSZ were selected for dynamic study of storability in the process of artificial aging treatment. The decreasing tendency of germination ratio of Xiushui 11, Zhe 733 and KSZ was as 20 to 36 time as much as that of LOX-3 lacking mutant, resulting in that Lox-3 lacking mutant might be a long-storabilty material.3. The storabilty of 27 indica near-isogenic lines and 15 japonica isogenic lines were investigated, it shows that the storability of indica near-isogenic lines is better than japonica, but among near-isogenic lines prominent difference exsits.vi4. 38 rice varieties were screened for morphological index and storability. The results indicate that the correlation coefficient between storability and morphological index in 38 conventional varieties are highly significant. Among the six taxonomic characters of morphological index, the correlation coefficients between storability and CHH (color of hull when heading), hairiness of hull and phenol reaction were highly significant, the correlation coefficients between storability and LPf (length of the first and second panicle internode) and leaf hairiness were significant.5. Quantitative trait loci (QTL) controlling long-storability in rice were identified using 127 DH lines derived from a cross between an indica variety ZYQ8 and a japonica variety JX17. A total of 3 QTLs were detected on chromosome 9, 11 and 12 with the phenotypic variation explaination 11.9%, 22.8% and 10.8%, respectively. The total phenotypic variation explained by three putative QTLs was 38.3% calculated by means of the multiple-QTL model. The storability of 3 chromosome segment substitution lines was also investigated.6. The long-storability and Lox-3 lacking mutant were used for rice storability improvement, many prominent lines were selected in the progeny lines.