摘要
应用包括３套遗传体系基因效应的数量性状发育遗传模型，分析了１２个籼稻亲本在４ 个不同稻米发育时期的糙米厚性状。结果表明，三倍体胚乳、二倍体母体植株基因的加性和显 性效应以及细胞质效应均可以明显影响各个稻米发育时期的糙米厚度，其中灌浆始期以二倍 体母体植株效应为主，灌浆中后期以三倍体胚乳效应为主，成熟期则以细胞质效应为主。在４ 个不同发育时期中，控制糙米厚的基因加性效应和显性效应交替为主。胚乳显性方差和母体 显性方差均达到显著水平，表明对糙米厚性状进行杂种优势利用是可行的。条件方差分量分 析发现，控制糙米厚性状表现的胚乳、细胞质和母体植株基因，在多数发育时期中均有新的表 达，且以稻米灌浆期为主，其中开花后第８～１４ｄ是控制糙米厚性状基因表达最为活跃的时期。 各遗传体系在接近稻米成熟时（开花后第２２～２８ｄ），新基因表达量急剧下降，甚至关闭。一些 基因效应，尤其是净细胞质效应存在着个别发育时期间断表达的现象。不同发育时期间糙米 厚的遗传相关分析表明，显性相关和细胞质相关在有些发育时期达到显著或极显著水平，且 成熟期糙米厚与前面各发育时期的糙米厚之间的关系最为密切。
Analysis of developmental genetic effects for brown rice thickness (BRT) trait in indica rice (Oryza sativa L.) at four different filling stages was conducted and a developmental genetic model and corresponding statistical approaches for quantitative traits of triploid endosperm in cereal crops was used. The results indicated that the diploid maternal plant triploid endosperm and cytoplasmic genetic effects were important for BRT trait at all filling stages of rice and those effects were the major effect at initial medium, filling period and mature period respectively. The additive and dominance effects were the major effect alternatively at four filling stages of rice. Significant endosperm and maternal dominance effects for BRT suggest that the utilization of heterosis for BRT is viable. The results of conditional genetic variance components shown that the expression of new quantitative genes in endosperm, cytoplasm and maternal plant for BRT was found at most filling stages of rice. The gene expression was most active at the early filling stages, especially at the second stage (8-14 days after flowering). Near to mature period (22-28 days after flowering), however, the expression of genes decreased sharply and even closed. The phenomena that the genes expressed spasmodically, i.e. the net genetic effects equaled to zero in some filling stages were detected for some genetic effects. Dominance and cytoplasmic correlation coefficients were significant at 0.05 or 0.01 probability level in some filling stages meanwhile there were the most strong relationship between mature period and other periods for BRT.
基金
国家自然科学基金!(编号39830250)
浙江省科委资助
关键词
发育遗传
遗传方差
籼稻
糙米厚度
brown rice thickness
developmental genetics
genetic variances and conditional genetic variances
indica rice (Oryza sativa L.)
genetic correlations
