水稻抽穗期耐热QTL的定位研究

In this paper, a japonica rice (Oryza sativa L.) variety Nipponbare, an indica variety 9311 and a set of chromosome segment substitution lines (CSSLs) which were generated using Nipponbare as the recipient parent and 9311 as the donor parent were used as the experimental materials. The CSSLs were grown in 2012 (normal temperature condition) and 2013 (high temperature condition) in Yangzhou, Jiangsu, and were used to map the quantitative trait loci (QTLs) for heat tolerance, based on the heat tolerance index [(The seed setting rate under normal temperature condition - The seed setting rate under high temperature condition) / The seed setting rate under normal temperature condition]. As a result, three QTLs for heat tolerance in rice were mapped on chromosomes 2, 4 and 12, respectively. They had LOD (logarithm of odds) scores of 2.56, 4.02 and 2.79, and contribution rates of 4. 95%, 7.99% and 5.44%. Among them, qHT12.1 showed positive effect, while qHT2.1 and qHT4.1 showed negative effect on heat tolerance. The results lay a foundation for the fine mapping and cloning of the QTLs and genes related to heat tolerance, and for the breeding of heat-tolerant rice varieties.