水稻籼粳型品系杂种籽粒充实度的遗传分析

Genetic Analysis on Grain Plumpness of Hybrids in Indica-Japonica Lines of Rice

利用 4个不同遗传背景的籼粳型品系及 1个粳型广亲和品种与籼型光温敏不育系配组杂交 ,对籽粒充实度进行遗传分析。结果表明 :偏籼型品系G2 12 3、G2 4 17- 1和偏粳型品系G30 0 5 - 4 - 1的杂种F1籽粒充实度表现正常 ,而粳型品系G2 6 15及粳型广亲和品种 0 2 4 2 8的杂种F1籽粒充实度未达正常水平。G2 4 17- 1、G30 0 5 - 4 - 1以及G2 12 3具有较好的籽粒充实度一般配合力 ,而籽粒充实度特殊配合力高的组合多数源于一般配合力高的亲本配组 ,利用一般配合力高的亲本配组可以克服杂种后代的籽粒充实不良现象。籽粒充实度的遗传力较高 ,且以基因的加性作用效应为主 ,父本即籼粳型品系的基因加性作用效应大于母本即籼型光温敏不育系的基因加性作用效应。试验表明籼粳中间型品系在克服两系亚种间杂交稻籽粒充实不良现象上具有重要的作用和地位。

The genetic analysis was made on grain plumpness of hybrids in indica japonica lines(IJLs) with different genetic differentiation mated with indica photo thermo sensitive male genetic sterile lines (PTMGS). The results are shown as follows: The grain plumpness is normal in hybrids of indica tendentious G2123, G2417-1 and japonica tendentious G3005-4-1, but is abnormal in hybrids of japonica G2615 and 02428 respectively. The general combining ability(GCA) and grain plumpness of G2417-1, G3005-4-1 and G2123 are better than others, and most of crosses with high specific combining ability(SCA) are derived from mating by those parents with high GCA, so it is an effective way to overcome the worst grain plumpness in hybrids using high GCA parents to cross. The heritability of grain plumpness is high and it is mainly controlled by genetic additive effects, and the males (IJLs) contribute more than females(PTMGS) on genetic additive effects. The lines between indica and japonica play an important role to overcome the worst grain plumpness of intersubspecific hybrids