Abstract: The grain weight per panicle(GW) and 1000-grain weight(TGW) of rice were investigated on 129 doubled haploid(DH) lines grew in two different seasons.The mixed-model based on composite interval mapping approach(MCIM) was used to detect QTLs.There were 15 QTLs detected underlying each trait.Among them,6 QTLs were responsible for simultaneous expression of the two traits.All QTLs detected were located in the marker intervals of the other 10 chromosomes apart from chromosomes 11 and 12.Of all QTLs for TGW,12 were detected with additive effects(a) and six pairs with additive × additive interaction effects(aa),and these QTLs hardly interacted with environment.Out of all QTLs for GW,seven were detected with a,of which four were environment-dependent,and six pairs with aa,of which one pair was sensitive to changes in environment.The estimated additive effect ofqTGW2 was 1.149 g,with a contribution of more than 10% to TGW.The additive effect of each QTL(qGW1, qGW7 and qGW8-1) had a contribution of more than 10% to GW when expressed in early season.

Key words: grain weight per panicle, 1000-grain weight, quantitative trait locus, gene mapping, epistasis, rice

摘要： 用基于混合线性模型的统计方法对一套来源于亲本IR64/Azucena的加倍单倍体群体在两个生产季节的水稻单穗重和千粒重进行了分析，各检测到15个QTL分别控制这两个性状，其中有6个QTL同时与这两个性状有关。所有QTL分布在除第11、12染色体以外的其余10条染色体的相应标记区间内。在控制千粒重的QTL中，12个QTL有加性效应，6对QTL带有加加上位性效应，它们不受环境条件的影响。在控制单穗重的QTL中，7个QTL具有加性效应，但其中4个QTL的表达随环境而异；6对QTL具有加加上位性，但其中1对对环境敏感。qTGW2的加性效应对千粒重的贡献率超过10%；3个QTL（qGW1、qGW7和 qGW81）在早季环境的加性效应对单穗重的贡献率亦都大于10%，但对环境敏感。

关键词: 单穗重, 千粒重, 数量性状座位, 基因定位, 上位性