两系杂交水稻千粒重的遗传研究

对8个籼型光温敏不育系母本与30个恢复系品种父本配制所获得的74个两系杂交水稻千粒重性状配合力遗传进行了分析。结果表明:(1)两系法杂交水稻杂种F1谷粒千粒重与父本(恢复系)、母本(不育系)和双亲的平均谷粒千粒重均呈显著正相关,相关系数分别为0.4308、0.3523和0.5656。(2)6×6不完全双列杂交法配合力分析结果表明,两系杂交水稻千粒重性状的表现在组合间差异达极显著水平。父、母本的一般配合力效应和组合的特殊配合力效应均达显著差异;在籽粒千粒重表现中,一般配合力方差和特殊配合力方差分别占整个基因型方差的93.98%和6.02%,说明一般配合力对籽粒千粒重的作用远大于特殊配合力;在其双亲的一般配合力作用中,母本对籽粒千粒重的作用大于父本。(3)两系杂交水稻千粒重性状遗传的广义遗传率为99.40%,狭义遗传率为93.41%,说明千粒重性状的遗传以基因的加性效应为主。

Genetic Studies on 1000-Grain Weight of Rice Hybrids by Two-Line Method

In this study, 74 combinations were obtained by crossing 8 photo-thermo-sterilities with 30 restoring lines. Their combining ability of 1000-grain weight was studied. The 1000-grain weight of the hybrids(F1) was found significantly positively correlated with head rice percentage of the male parentages and the female parentages and the average 1000-gram weight of the parents, and the correlation coefficient was 0.430 8**, 0.352 3*, 0.565 6** respectively. The difference in 1000-grain weight was very significant among the combinations, and the difference in 1000-grain weight combining ability(GCA) and special combining ability(SCA) were highly significant among the combinations. The 1000-grain weight of hybrids was controlled by GCA of the parentages and the SCA of combinations, and the GCA of the parentages played a more important role. The heredity of 1000-grain weight in hybrid rice(F1 ) by two-line method is mainly controlled by gene. The h2B is 99.40 %, and the h2N is 93.41%, indicating the heredity of the 1000-gram weight is based on gene addition.