奥利亚罗非鱼形态性状与体重的通径分析

为提高奥利亚罗非鱼的育种效率,明确选育目标,分别测定了205尾奥利亚罗非鱼的全长(X1)、体长(X2)、头长(X3)、躯干长(X4)、体高(X5)、体宽(X6)、尾柄长(X7)、尾柄高(X8)和体重(Y)共9个性状,计算相关系数,采用通径分析方法计算了以体重(Y)为依变量、其他性状为自变量的通径系数和决定系数。结果表明,奥利亚罗非鱼雄鱼全长、体长、头长、体高、体宽和体重的相关关系均达到显著水平(P﹤0.05),雌鱼各形态性状间的相关关系均达到极显著水平(P﹤0.01)且均为正相关关系。影响雄鱼体重的重要性状是全长、尾柄高、体宽、头长;影响雌鱼体重的重要性状是体宽、体长、躯干长、体高、全长。全长(0.504)对雄鱼体重的决定系数最大,体宽(0.450)对雌鱼体重的决定系数最大。经多元回归分析,选择偏回归系数显著的变量,与体重建立多元回归方程,奥利亚罗非鱼雄雌鱼的形态性状与体重的多元回归方程分别为:Y=-688.287+2.468 X1+9.453 X6+0.676 X8和Y=-418.506+0.871 X1+12.551 X6。

Path Analysis on Morphological Traits and Body Weight of Oreochromis aureus

For the sake of enhancing breeding efficiency of Oreochromis aureus and identifying clear objects to breed, data for this study were collected from 205 Oreochromis aureus.Their body weight(Y),total length(X1),body length(X2),head length(X3),trunk length(X4),body depth(X5),body width(X6),caudal peduncle length(X7) and caudal peduncle depth(X8) were measured.Path analysis was adopted to calculate correlation coefficient using body weight(Y) as dependent variable and other traits as independent variable from which coefficient of determination and path coefficient were gained.The results indicated that the male Oreochromis aureus correlation coefficients of total length,body length, head length,body depth,body width and body weight all reached significant level(P<0.05);the female Oreochromis aureus correlation coefficients of each morphological trait reaching extremely significant level(P<0.01) were of positive correlation relationship.The total length,caudal peduncle depth,body width and head length were the critical factors on the body weight of male Oreochromis aureu,while the major factors on the body weight of female Oreochromis aureus were the body width,body length,trunk length,body depth,and total length.The determination coefficients of total length(0.504) played a decisive role in body weigh of male Oreochromis aureus,and the determination coefficients of body width(0.450) mostly affected the body weight of female Oreochromis aureus.In accordance with multiple regression analysis,the morphometric traits reaching the level of significance(P<0.05) and body weight were used to establish the multiple regression equations,which were presented as Y=-688.287+2.468X1+9.453X6+0.676X8 in male Oreochromis aureus and Y=-418.506+0.871X1+12.551X6 in female Oreochromis aureus.