大菱鲆体重性状不同生长期的遗传分析

Genetic analyses for body weight trait in turbot (Scophthalmus maximus L.) at different developmental stages

采用条件数量性状加性-显性遗传模型和统计分析方法,对大菱鲆（Scophthalmus maximus）体重性状不同生长期进行遗传分析；基于von Bertalanffy模型,对大菱鲆6种交配组合的生长曲线划分为缓慢生长期、快速生长前期、快速生长后期和渐进期,并与各生长期所对应的遗传分析结果进行比对。结果表明,6种交配组合的缓慢生长期、快速生长前期和快速生长后期基本上是一致的。在缓慢生长期,检测到新的条件加性方差和条件显性方差,其相应的条件加性方差分量比率均未达到显著水平,相应的条件显性方差分量比率均达到显著（P〈0.05）或极显著水平（P〈0.01）；在快速生长前期,交互检测到达到极其显著水平的条件加性方差和条件显性方差,其相应的条件加性方差分量比率和条件显性方差分量比率分别在15~18月龄和12~15月龄达到极显著水平（P〈0.01）；在快速生长后期,同时检测到达到极其显著水平的条件加性方差和条件显性方差,其相应的条件加性方差分量比率和条件显性方差分量比率均达到极其显著水平（P〈0.01）,但同期的条件显性方差分量比率高于条件加性方差分量比率。本研究通过探讨大菱鲆体重性状在特定生长发育期的遗传机理,深入了解复杂数量性状时空动态变化的遗传生态学机制及其遗传规律,旨在为提高大菱鲆育种的预见性和选择效率提供理论参考。

According to the theory of developmental genetics, genes are expressed selectively at different growth stages in a time-and/or space-specific manner. The whole process of genetic control during development cannot be revealed by data collected at one single time-point;the dynamics of gene expression need to be monitored at various develop-mental periods during ontogeny. Genetic analyses for body weight trait in turbot, at different developmental stages, were conducted using a conditional genetic model and statistical methods, including additive and dominance effects for quantitative traits. At the same time, the growth curves of six mating combinations of turbot were divided into four de-velopmental stages, i.e. slow-growing period, fast-growing early period, fast-growing late period and asymptotic grow-ing period, based on the von Bertalanffy model （time）. Genetic dynamic changes were compared with the net variance components and the proportion of phenotype variance at the different developmental stages. The results showed that the slow-growing period, fast-growing early period and fast-growing late period of the six mating combinations are basi-cally similar. In the slow-growing period, new net additive/dominance variance components were detected. The propor-tions of net additive variance components to phenotype variance were not significantly different, while the proportions of net dominant variance components were significantly/very significantly different. In the fast-growing early period, net additive/dominance variance components with significant differences were alternatively detected and the propor-tions of net additive/dominant variance components to phenotype variance were very significantly different at 15-18/12-15 months. In the fast-growing late period, net additive/dominant variance components with significant dif-ferences were simultaneously detected and the proportions of net additive/dominant variance components to phenotype variance all were very significantly different.