Abstract: Two developmental genetic models for quantitative traits of seeds in cereal crops, i.e. unconditional model referred to the analysis of cumulative measurements along the developmental stages, and conditional model referred to the gain analysis throughout the developmental stages, were used to analyse the developmental genetics of valine content at different grain filling stages in the indica-japonica hybrid rice. The valine content was governed by diploid maternal plant genes, triploid endosperm genes, cytoplasmic genes and their environmental interaction effects. Those genes were interval expressions among grain filling stages, and the most active stage when genes expressed was 8-14 days after flowering. Heritability analysis expressed that maternal heritability, cytoplasmic heritability and their environmental interactions were important at all the five filling stages. Single plant selection during early breeding generations would be effective to enhance the content of valine in rice breeding. Prediction of genetic effects in rice parents showed that Zhe 38A, Zhenong 8010A, Jin 23A, and Zhong 9308 could be used for improving the valine content in indica-japonica hybrids. The results also showed that Zhe 38A was more stable in different environmental conditions, it is the best one of the 12 parents tested for improving the valine content in rice breeding.

Key words: hybrid rice, indica-japonica hybrid, grain filling, developmental genetics, valine, rice quality, heritability

摘要： 采用可以估算不同发育时期基因累加效应和特定发育时期净遗传效应的遗传模型和统计分析方法，研究了不同环境条件下籼粳交稻米灌浆过程中缬氨酸含量的发育遗传规律。结果表明，控制籼粳交稻米缬氨酸含量表现的基因在稻米多数发育时期均有表达，其中以颖花开花受精后第8~14天表达量最大。遗传率分析揭示缬氨酸含量在稻米5个不同发育时期的母体和细胞质普通遗传率及其相应的环境互作遗传率均较高，育种低世代进行单株选择可以提高稻米缬氨酸含量的育种效率。亲本遗传效应分析表明，浙38A、浙农8010A、金23A和中9308等4个亲本有利于增加籼粳交稻米的缬氨酸含量，其中浙38A受环境影响最小，可应用于配制高缬氨酸含量的杂交稻新组合。

关键词: 杂交水稻, 籼粳交, 灌浆, 发育遗传, 缬氨酸, 稻米品质