卵形鲳鲹不同月龄选育群体主要形态性状与体质量的相关性分析

为探讨卵形鲳鲹不同月龄选育群体主要形态性状对体质量的影响,跟踪测量了1月龄,4月龄,7月龄,10月龄和13月龄个体的全长(x1),体长(x2),体高(x3)和体质量(y),共测量2 635尾。运用相关分析、多元回归分析和通径分析的方法,计算了以体质量为因变量,其他形态性状为自变量的相关系数、通径系数和决定系数,剖分各性状对体质量的影响,建立最优多元回归方程。结果显示,在不同生长阶段,4个性状间的相关系数在0.017～0.960之间,除4月龄个体体高与其他性状间相关性不显著外,其他月龄群体各性状两两之间的相关性均达到了极显著水平;1月龄和4月龄个体全长对体质量的直接作用最大,7月龄、10月龄和13月龄个体则是体高对体质量的影响最大;各性状对体质量决定程度分析与通径分析变化趋势一致,各月龄群体全长、体长、体高估算体质量的多元线性回归方程的拟合度良好(86.9%～90.6%)。研究表明,影响体质量的主要形态因素已找出,选育时期不同,所选择的形态性状也应有所差异,为卵形鲳鲹选择育种提供了必要的技术参数。

Correlation analysis of major morphometric traits and body weight of selective group at different month ages of Trachinotus ovatus

To investigate the effect of major morphometric traits of selective group of Trachinotus ovatus at different month ages on body weight,2 635 specimens at 1-month-old stage,4-month-old stage,7-month-old stage,10-month-old stage and 13-month-old stage were measured respectively in terms of total length(x₁),body length(x₂),body height(x₃)and weight(y).Correlation coefficients,path coefficients and determination coefficients of each trait to body weight were calculated through path analysis and multiple linear regression.Effects of each morphometric trait on body weight were also dissected and then the optimal regression equation was established.The results showed that the correlations among 4 traits ranged from 0.017 to 0.960,and all reached significant level(P<0.01)at different stages except that at 4-month-old stage.At 1-month-old stage and 4-month-old stage,the trait with strongest direct effect on body weight was the total length,but that at other stages was the body height.The result of determinant coefficient analysis was consistent with that of path analysis,and the fitness of equations at different stages was good(86.9%-90.6%).It indicated that the major morphometric traits affecting body weight were found and traits for selection should be considered at different stages,which provided technical parameters for selective breeding for T.ovatus.