不同月龄云龙石斑鱼表型性状的主成分与通径分析

Principal component and path analysis of phenotypic traits of Yunlong grouper with different month ages

为研究云龙石斑鱼Epinephelus moara♀×Epinephelus lanceolatus♂不同生长阶段表型性状间关系,分别测定了4月龄、9月龄和15月龄云龙石斑鱼体质量(Y)、全长(X1)、体长(X2)、头长(X3)、体高(X4)、眼后头长(X5)、躯干长(X6)、尾柄长(X7)和尾柄高(X8)等形态性状,并对不同月龄表型性状进行了相关分析、主成分分析和通径分析。结果表明:3个月龄组云龙石斑鱼形态性状对体质量的最优多元回归方程分别为Y4月龄=-47.887+3.335 X1+2.139 X2-3.729 X7+19.582 X8,Y9月龄=-313.801+17.985 X1-7.144 X3+11.193 X4+37.145 X8;Y15月龄=-897.768+20.951 X1+70.512 X4-33.298 X7+81.547 X8;云龙石斑鱼各月龄表型性状间均呈不同程度的正相关,除9月龄尾柄长外,各形态性状与体质量的相关性均达到极显著性水平(P<0.01);4月龄和9月龄第一主成分均指向增长、增重因子,15月龄第一主成分指向增长、增重和体高因子,3个月龄第二主成分均指向尾柄因子;4月龄和9月龄全长对体质量直接作用均最大(分别为0.485、0.831),15月龄体高对体质量直接作用最大(0.440),决定系数分析结果与通径分析结果一致。研究表明,云龙石斑鱼在所测的3个月龄阶段均以增长、增重为主,建立的多元线性回归方程能够估算不同月龄云龙石斑鱼的体质量。

Body weight(Y),total length(X1),body length(X2),head length(X3),body depth(X4),head length behind of eyes(X5),trunk length(X6),caudal peduncle length(X7),and caudal peduncle depth(X8)were measured in 339 samples of Yunlong grouper Epinephelus moara♀×E.lanceolatus♂with 4,9 and 15 month old age collected from a hatchery in Xiamen,Fujian province,and were analyzed by principal component and path analysis to probe into the relevance of various phenotypic traits of Yunlong grouper and the corresponding body weight.The optimal regression equation of Yunlong grouper was shown to be expressed as Y4=-47.887+3.335 X1+2.139 X2-3.729 X7+19.582 X8 for 4 month old grouper,Y9=-313.801+17.985 X1-7.144 X3+11.193 X4+37.145 X8 for 9 month old grouper,Y15=-897.768+20.951 X1+70.512 X4-33.298 X7+81.547 X8 for 15 month old grouper.There were positive correlations among phenotypic traits of the grouper with different month ages,with very significant positive correlation between body weight and various phenotypic traits of grouper with different month ages(P<0.01)except the correlation with X7 at the age of 9-months.The first principal component analysis reflected with ages of 4-months and 9-months and the body length gain,body weight gain and body depth factors in Yunlong grouper with age of 15-months.The second principal component reflected the caudal peduncle length factor in Yunlong grouper with 3 month old age.The maximal direct effect on body weight was total length in Yunlong grouper with age of 4-months(determinant coefficient of 0.485)and 9-months(determinant coefficient of 0.831),meanwhile,the maximal direct effect on body weight was body depth in Yunlong grouper with age of 15-months(determinant coefficient of 0.440),determinant coefficient analysis being consistent with that of path analysis.The findings indicate that the length growth and weight gain are main characteristics trend at three month stages,and that the established multiple linear regression equations can be used to estimate body weight of Yunlong grouper with different month ages.