中文摘要：

【目的】大豆分枝数与大豆株型及产量关系密切,检测世代间可稳定遗传的大豆分枝数QTL,为大豆株型和产量育种的分子标记辅助选择奠定基础。【方法】根据科新3号×中黄20杂交组合F2群体构建的分子遗传图谱,对F2：4群体进行QTL定位,并利用定位QTL两侧的标记选择残余杂合个体,构建残余杂合系,对分枝数相关的QTL进行验证。【结果】在F2：4群体将分枝数QTL（qBN-c1-1）定位在C1连锁群区间Satt294-Satt399,贡献率为12.01%,来自于科新3号亲本的加性效应为-0.51;用F2：5选出残余杂合系,将控制大豆分枝数QTL定位在C1连锁群Satt399-Satt361区间,贡献率为11.16%,来自于科新3号的加性效应为-1.74,研究结果与F2：4群体一致。【结论】位于C1连锁群的与分枝数相关的QTL在该遗传背景下可稳定遗传。

英文摘要：

【Objective】 Branch number is one of the major factors related to both plant type and yield in soybean. The objective of this study was to map the branch number related QTL, and analyze the inheritance stability over generations for the improvement of yield in marker assistant selection （MAS） in soybean. 【Method】 A molecular genetic map was constructed by using the F2 population derived from KeXin3×ZhongHuang20, which was used to map the branch number related QTL with F2：4 population. Residual heterozygous lines were selected from F2：5 population by two markers flanking the QTL, to construct secondary separated population. 【Result】 The QTL related to branch number was located at the interval of Satt294 and Satt399 on linkage group C1, explained 12.01% of the variance and the additive effect is -0.51, and the effect originated from KeXin3. QTL analysis by the residual heterozygous line mapped the QTL of soybean branch number between Satt399 and Satt361, with R2 of 11.16% and additive effect of -1.74, and the inhibited effect also originated from Kexin3, which was the same with result of F2：4 population. 【Conclusion】 The branch number related QTL was mapped on soybean linkage group C1 and could be stably inherited in different generations from the same cross.