许氏平鲉不同月龄选育群体形态性状的主成分与通径分析

Principal component and path analysis of morphological traits of selective groups at different month ages of Sebastes schlegeli

为研究许氏平鲉不同月龄选育群体性状的生长规律特征及形态性状对体质量的影响,采用相关分析、主成分分析、通径分析和多元回归分析方法对12月龄、15月龄和18月龄许氏平鲉个体的全长、体长、头长、躯干长、体高、尾柄长、尾柄高和体质量8个性状进行分析。结果显示,各月龄许氏平鲉性状之间均呈现显著的正相关,其中以全长与体长的相关性最为显著。各月龄许氏平鲉的第一主成分均指向增长、增重因子;第二主成分有所不同,12月龄未提取第二主成分,15月龄和18月龄第二主成分分别指向躯干因子、尾柄因子。12月龄和15月龄许氏平鲉体长和体高对体质量的直接作用均最大（0.340、0.314和0.347、0.324）,18月龄全长对体质量的直接作用最大（0.498）,各性状对体质量决定程度与通径系数变化趋势一致。各月龄的不同形态性状对体质量最优回归方程的建立,能准确预测体质量的变化。研究表明,由于许氏平鲉生长阶段的不同,各性状的生长速率及所选形态性状对体质量的影响均存在一定差异,建议把体长和体高（12~15月龄）、全长（18月龄）作为育种工作的目标性状,达到有效提高选育效率的目的,为许氏平鲉的选育工作提供理论依据和技术参数。

In order to research growth characteristics and the effect of morphological traits on body weight of selective groups of Sebastes schlegeli at different month ages, this thesis analyzed the data of body weight, full length, body length, head length, trunk length, body depth, caudal peduncle length and caudal peduncle depth at different month ages, by the methods of principal component, correlation analysis, path analysis and multiple regression analysis. The results showed that notable correlation was found among all the morphological traits of S.schlegeli at different ages, especially between full length and body length. The first principal component always reflects the length and body weight factor of S. schlegeli at different growth phases. However, the second principal component was different and reflected the trunk length factor at 15-month-old and the caudal peduncle factor at18-month-old, but was not available at 12-month-old. The traits with strongest direct effect on body weight were body length and body depth（0.340, 0.314 and 0.347, 0.324） at 12-month-old and 15-month-old, meanwhile, the full body and body depth（0.498） at 18-month-old. The result of determinant coefficient analysis was consistent with that of path analysis. The growth rate of traits and effect on weight selected traits were not the same because of the different growth stages of S. schlegeli. We proposed that the body length and body depth were the target traits for selective breeding of S. schlegeli at 12-month-old and 15-month-old, We should pay attention to selecting full length at 18-month-age to improve the accuracy of breeding projects. The research provided theoretical evidence and technical parameters for selective breeding of S. schlegeli.