Abstract:

【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.

Key words: soybean, branch number, residual heterozygous line, quantitative trait locus (QTL)