中美半矮秆大豆杂交早期世代农艺性状遗传变异研究

以三个中美半矮秆大豆杂交组合为材料，通过对其自交及回交后代各主要农艺性状的遗传参数的分析，为半矮秆大豆后代的选择和品种选育育种提供了一定的理论依据。试验结果表明：中美半矮秆大豆品种间其性状特别是分枝性状的明显差异，加之地理远缘等原因，其Ｆ１代多数农艺性状具有明显的超亲优势，自交及回交后代分枝性状有着超常幅度的变异；除了与通常杂交组合中株高、主茎节数、百粒重等表现较大的遗传力相同外，此种组合后代的分枝性状也表现了较高的遗传力。中美半矮秆大豆杂交后代所有分枝性状变异广泛，相对预期遗传进度大，且与目标性状产量相关值较大，决定了在此组合早代选择的必要性。

STUDY ON GENETIC VARIATION IN EARLY GENERATIONOF CHINA-AMERICA SEMI-DWARF SOYBEAN CROSSES

Three China-America semi-dwarf soybean crosses were made, and the progesis had been used for study on genetic variation in early generation for those crosses. The objective of this study was to provide theoretical bases for semi-dwarf soybean breeding,and to explore the meaning for widening soybean seed resourses. The experimental results showed that: Heterosis of F1 of many agronomic characters is very prevalent. The evident differences of parents in branches give rise to great variation of progesis in these characters. Heritability of plant height, nodes on main stem, weight of 100 seeds is comparatively high, and the heritability of branch characters is also very high. The variation of all the branch characters of progesis is very wide, and the comparatively expected genetic advances of these charcters in the F2 are quite great, and this means that selecting potential on these characters will be fruitaful.