Abstract: A double haploid (DH) population derived from a cross between Azucena (japonica) and IR64 (indica), was used for detecting additive effect(A) of quantitative trait loci(QTL) and their additive×additive epistasis(AA) for rice heat tolerance under field and greenhouse experiments. Seed setting rate of 109 DH lines was scored as the parameter of heat tolerance. QTL analysis was conducted by using the constructed molecular linkage map and software QTLmapper 1.0. Six additive effect QTLs were detected on chromosome 1,3,4,8 and 11, respectively. Eight pairs of epistasis effects QTLs were detected on chromosome 1,2,3,4,5,7,8 and 11 with variance explained being 2.27%-8.13%. Photosynthetic rate and heat tolerance were measured at maximum tillering and heading stage, and results showed that photosynthetic rate at heading stage was significantly positive correlated with heat tolerance.

Key words: heat tolerance, quantitative trait locus, epistasis analysis, photosynthetic rate, correlation, rice

摘要： 应用典型的籼粳交组合IR64×Azucena花药培养的DH群体及其已构建的分子连锁图谱，在田间及温室高温条件下对该DH群体的结实性状进行考查，采用QTLmapper 1.0软件检测控制结实率的加性和上位性效应的QTL。在第1、3、4、8和11等5条染色体上，共检测到6个具有加性效应的QTL，其中位于第1、3染色体的2个加性效应QTL来自父本Azucena的等位基因，它们是耐热的QTL，能分别提高结实率9.50和6.46个百分点，其贡献率分别为19.15%和2.86%；位于其余3条染色体的4个加性效应的QTL来自母本IR64的等位基因，它能提高结实率4.33~10.37个百分点，在第1、2、3、4、5、7、8、11等8条染色体之间还检测到8对加性×加性上位性效应，其贡献率为2.27%~8.13%。同时还对水稻分蘖盛期和抽穗期进行了光合速率的测定，发现抽穗期剑叶光合速率与耐热性呈显著的正相关。

关键词: 耐热性, 数量性状座位, 上位性分析, 光合速率, 相关性