水稻染色体片段代换系苗期耐冷评价及主效位点qSCT11效应验证

Rice is a main staple crop in China. Low temperature is a major limitation in rice production. There are 15 million hectares of rice around the world often facing the chilling stress during variouse rice growth stages, which has resulted in a huge loss of grain yield. Meanwhile it has greatly limited the range of rice cultivation area. Therefore, improvement of cold tolerant rice varieties is an important breeding goal. We evaluated cold tolerance of two representative rice varieties, japonica Nipponbare and indica 93-11 at seedling stage, and found that Nipponbare is much stronger in cold tolerance than that of 93-11. Furthermore, the population consisting of 122 chromosome segment substitution lines that derived from Nipponbare (NIP) and 93-11 was used to evaluate their cold tolerance at the seedling stage. A total of 14 loci for seedling cold tolerance was detected. Using a near-isogenic line and its derivative BC1F2 population, we have verified the effect of a major locus qSCT11, at which the Nipponbare alleles could enhance seedling cold tolerance. The physiological experiment on the near-isogenic line indicates that stability of cell membrane and reduction of lipid oxidation could be a physiological basis of seedling cold tolerance in rice.