苏丹鱼形态性状对体质量的相关性及通径分析

Correlation and path coefficient analysis between morphometric traits and body weight in Leptobarbus hoevenii

【目的】明确人工养殖条件下苏丹鱼(Leptobarbus hoevenii)体质量与形态性状的相关性,为苏丹鱼优良形态性状的选育提供理论依据。【方法】从人工养殖的4月龄苏丹鱼池塘中随机挑选苏丹鱼116尾,测量其体质量(Y)及全长(X_(1))、体长(X_(2))、头长(X_(3))、躯干长(X_(4))、体高(X_(5))和体宽(X_(6))等形态性状,利用相关分析和通径分析法筛选影响体质量的主要性状,并以逐步回归分析法构建多元回归方程。【结果】苏丹鱼的全长、体长、头长、躯干长、体高和体宽等形态性状与体质量间均呈极显著正相关(P<0.01)。通径分析结果表明,全长、体长、体高和体宽是影响苏丹鱼体质量的主要形态性状,对体质量的直接作用排序为体长(0.364)>全长(0.291)>体高(0.245)>体宽(0.143),间接作用排序为体高(0.645)>全长(0.644)>体宽(0.589)>体长(0.587)。决定系数(R^(2))分析结果表明,全长、体长、体高和体宽对体质量的直接R^(2)与间接R^(2)总和为0.941(大于0.850),说明苏丹鱼的体质量主要由这4个形态性状决定。多元回归分析结果表明,苏丹鱼体质量与形态性状的多元回归方程为Y=-94.861+4.385X_(2)+8.089X_(5)+6.002X_(6)+2.842X_(1)(R^(2)=0.946)。将全长、体长、体高和体宽4个形态性状分别与体质量进行模型拟合,最优拟合模型分别为三次函数、幂函数、幂函数和三次函数,方程式分别为Y=0.265X_(1)^(3)-0.003X_(1)^(2)+8.819、Y=4.278X_(2)^(0.290)、Y=0.766X_(5)^(0.383)和Y=0.032X_(6)^(3)+1.044,对应的R^(2)分别为0.892、0.925、0.817和0.552。【结论】在苏丹鱼生产及选育过程中,体长可作为主要目标性状进行选择,全长、体高和体宽可作为辅助性状进行选择。

【Objective】To analyze the correlation between body weight and morphological traits of Leptobarbus hoeve-nii in artificial culture,and to provide theoretical basis for the selection and breeding of excellent morphological traits of L.hoevenii.【Method】In this study,1164-month-old L.hoevenii samples were measured under artificial feeding condi-tions,and including 7 traits:body weight(Y),full length(X_(1)),body length(X_(2)),head length(X_(3)),carapace length(X_(4)),body height(X_(5))and body width(X_(6)).Correlation analysis and path analysis were used to screen the main traits affecting body weight,and multiple regression equations were constructed by stepwise regression analysis.【Result】There were ex-tremely significant positive correlations(P<0.01)between morphological traits(full length,body length,head length,carapace length,body height and body width)and body weight in L.hoevenii.The results of the path analysis showed that four morphological traits,including full length,body length,body height and body width,were the main traits affecting the body weight of L.hoevenii.The magnitude of the direct effect on body weight was body length(0.364)>full length(0.291)>body height(0.245)>body width(0.143),and the indirect effect was body height(0.645)>full length(0.644)>body width(0.589)>body length(0.587).The analysis results of determination coefficients(R^(2))showed that the sum of direct R^(2) and indirect R^(2) of full length,body length,body height and body width to body weight was 0.941,which was greater than 0.850,indicating that the body weight of L.hoevenii was mainly determined by these four morphological traits.Finally,multiple regression equations were established for L.hoevenii,that was Y=-94.861+2.842X_(1)+4.385X_(2)+8.089X_(5)+6.002X_(6),(R^(2)=0.946).The four morphological traits,including full length,body length,body height and body width,were fit-ted with body weight respectively.The fitting results showed that the best-fitting models of full length,body length,body height and body width were cubic function,power function,power function and cubic function,with the equations Y=0.265X_(1)^(3)-0.003X_(1)^(2)+8.819,Y=4.278X_(2)^(0.290),Y=0.766X_(5)^(0.383),Y=0.032X_(6)^(3)+1.044,corresponding to R^(2) of 0.892,0.925,0.817 and 0.552 respectively.【Conclusion】In the production and selection of L.hoevenii,body length can be used as the main target trait for selection,while full length,body height and body width can be used as secondary traits for selection.