施氏獭蛤壳体表型性状对体质量的影响分析

Effects of Shell Phenotypic Traits on Body Weight of Clam Lutraria sieboldii

为研究施氏獭蛤选育群体壳体性状对体质量的影响,随机选取经2代群体繁育的20月龄、养殖在水深5~7 m的泥沙质潮下带滩涂中的施氏獭蛤150个,测量壳长(x1)、壳高(x2)、壳宽(x3)、壳质量(x4)、体质量(y1)和软体质量(y2)表型性状,进行相关的通径分析。试验结果显示,施氏獭蛤表型性状参数中,壳质量变异系数最高,性状间相关性达到极显著水平(P<0.01),体质量同软体质量和壳质量相关性均达0.85以上;根据多元回归分析结果,壳质量对施氏獭蛤体质量和软体质量的影响最大,对体质量通径系数达到0.657,高出壳长0.369,对软体质量的影响程度下降,通径系数为0.436,高出壳长0.086,壳质量的直接作用大于间接作用;体质量(y1)和软体质量(y2)与壳长(x1)、壳质量(x4)的回归方程分别为:y1=-14.769+0.613x1+2.002x4(r2=0.806),y2=-0.980+0.281x1+0.500x4(r2=0.549),r2<0.850表明存在对体质量性状影响较大的其他因素。以上结果为施氏獭蛤性状选择提供基础数据。

Shell length(x1),shell height(x2),shell width(x3),shell weight(x4),body weight(y1)and soft part weight(y2)were measured in 150 samples of clam Lutraria sieboldii randomly collected from the 20-month-old population bred in 2 generations and cultured in the 5—7 m-deep sediment tidal zone and correlated by path analysis to evaluate the effects of shell phenotypic traits on body weight of the clam.It was found that the maximal coefficient of variance was in shell weight,with very significant difference in correlation coefficients between the phenotypic traits among the phenotypic parameters of the clam(P<0.01),followed by the correlation coefficients between body weight and shell weight and soft-body weight(over 0.850).The multiple regression analysis indicated that shell weight had a major effect on body weight traits of the clam,with the path coefficient of 0.369 between shell weight and body weight,and larger path coefficient of up to 0.657 between shell weight and shell length.The effect of shell weight on soft part weight was reduced,with path coefficient of 0.436 between shell weight and body weight,0.086 higher than that between shell weight and shell length,greater direct effect of shell weight than the indirect effect.The regression equation was expressed as y1=-14.769+0.613x1+2.002x4(r2=0.806)between shell length(x1)and shell weight(x4)to body weight(y1)and y2=-0.980+0.281x1+0.500x4(r2=0.549)between soft part weight(y2),r2<0.850,indicating that other factors had a impact on body weight traits.The findings provide basic data for the selection of traits for clam L.sieboldii.