关键词: 大豆, 数量性状, 自然选择, 重组自交系群体, 遗传结构, 环境条件

Abstract: 【Objective】The study was conducted to reveal that wheather there are differences in genetic structure between two RILs populations derived from the same soybean hybrid combination under two different environments and what the reason is for that.【Method】Four RILs populations were tested in this experiment. Populations “NJ(RN)P7”and “JN(RN)P7”were derived respectively from cross between Peking (as female) and 7605 (as male parents) under Nanjing and Jinan. And populations “NJ(RN)R7” and “JN(RN)R7” were derived respectively from cross between RN-9( as female) and 7605( as male parents) under Nanjing and Jinan.The natural selection effect on soybean major quantitative traits was distinguished under different environments by comparative the difference of its phenotype which was derived from the same cross.【Results】When these four RILs populations were planted respectively in Nanjing and Jinan, defferent significances were detected for plant height and branches in the two populations which derived from cross “Peking×7605”; so did the branches ,availability pods,seeds per plant,100 seeds weight in the other two populations derive from cross “RN-9×7605”. 【Conclusion】There are obviously natural selection effects on described traits as hereinbefore. It can be explained that there are really differences between two populations deriving from the same cross and it is confirmed by analyzing variation of phenotype.

Key words: Soybean, Quantitative character, Natrual selection, Recombinant Inbred Lines(RILs), Genetic Structure, Environment condition.