籼型三系杂交稻稻米中重金属镉含量的杂种负优势效应及配合力、遗传力分析

本文采用5 个不育系与6 个恢复系进行不完全双列杂交。从配制的杂交组合中选择30 个生育期基本一致的组合, 研究籼型杂交稻稻米中重金属Cd 含量的杂种优势表现及配合力、遗传力。结果表明: 稻米中Cd 含量有明显的杂种负优势效应; 不育系和恢复系稻米中Cd 含量的一般配合力效应及二者的特殊配合力效应均达极显著水平, 说明低Cd 含量组合的选育中双亲的遗传改良和组合的评价筛选都很重要。Cd 含量的广义遗传力与狭义遗传力均较高、且相差较小, 分别为97.73%和80.10%, 说明稻米Cd 含量以基因加性作用为主, 亲本改良在早期世代选择的效果较好。

Analysis of heterosis, combining ability and heritability of cadmium content in brown rice of tri-line indica hybrid rice

Five cytoplasmic male sterile (CMS) and 6 restorer lines of rice were used as parents in an incomplete diallel cross design. Thirty cross combinations with the same growth period were selected as materials in the analysis of heterosis, combined ability and heredity of Cd. The main results were as follow: A negative heterosis was noted in brown rice Cd content. For the CMS and restorer lines, the general and specific combination abilities about Cd content were both significant at P < 0.01. This showed that the breeding of combinations with low Cd accumulation depended on both genetic improvements and evaluation of the parents. For the Cd content, heredity in the broadest and narrowest sense was 97.73% and 80.10%, respectively. This explained that gene additive function was the main in the genetic code of grain Cd content. The results suggested that chosen parents of the early generation were good.