水稻对紫外线Ｂ辐射增强的抗性机制与基因定位

利用水稻抗、感紫外线Ｂ辐射影响的材料分析其不同生育期的抗性反应及保护机制；采用双列杂交分析抗紫外线Ｂ性状的遗传模型；以全生育期表现抗、感的亲本及其F和F2 DH群体牧希擞肦FLP、等技术、Mapmaker 软件和统计分析进行水稻抗紫外线Ｂ性状的分子标牵煌ü怂岵庑蚝偷阃槐浼际跬瓿苫蚨ㄎ弧

The results showed that enhanced ultraviolet-B radiation (UV-B) significantly changed the contents and the balance of polyamine and endogenous hormone in rice, decreased the contents of soluble protein and nucleic acid in rice leaves, then destroried the balance of carbon and nitrogen, deteriorated the parameters of chlorophyll a fluorescence, in turn decreased photosynthesis, finally led to reduce yield of rice. However, different cultivars had different resistance to enhanced UV-B radiation, which was related to the difference of the adaptive abilities and the protective mechanism in different rice genotypes. Dynamic genetic study showed that the trait resistant to UV-B radiation was characterized by quantative inheritance. The resistant performance in rice seedling stage was controlled by both additive and dominant effects, but mainly by the dominant effect. With the development of rice proceeding, the additive and dominant effects were expressed alternately. The approach of mRNA differential display (DD) was used to analyze gene differential expression of rice seedlings subjected to lowly enhanced UV-B radiation. The result showed that there were eighteen different fragments involved in the adaptation and regulation, fifteen of them were different in levels, two of them, which were recovered and re-amplified, appeared to be specific and were proved to be relative to the tolerance to the stress of lowly enhanced UV-B radiation. Our research showed that the sequence of the specific fragments was located in the OSJNBb0091N21BAC(GenBank accession No.:AC091122) of the tenth chromosome. The results in the present studies will be great of importance in our further research work on the molecular ecological mechanism of rice exposed to enhanced UV-B radiation and on the breeding of high resistance to UV-B radiation.