大竹蛏表型性状通径和回归分析

Path and Regression Analysis of the Phenotypic Characters of Solen Grandis

随机抽取野生大竹蛏(Solen grandis)63个,测定壳长等9个表型性状和活体质量,运用相关分析、通径分析定量分析大竹蛏表型性状对质量性状的影响效果.结果表明,9个表型性状与活体质量均呈现极显著正相关关系(P<0.01).壳长对活体质量的直接影响最大、间接影响最小,且直接影响大于间接影响;壳宽的直接影响亦大于间接影响;其余表型性状对活体质量的间接影响均大于直接影响,并主要通过壳长和壳宽间接影响活体质量.9个单独的决定系数和36个两两共同决定系数的总和Σd=0.933>0.850,表明表型性状是影响活体质量的重点性状.壳长对活体质量的决定程度最大(di=0.8271);在共同决定系数中,壳长和壳宽对活体质量的共同决定程度最大(dij=0.580 9).经多元回归分析,建立了表型性状与活体质量的回归方程:Y=-56.969+0.282X1+2.601X2+0.997 X6-0.191 X9.因此,在大竹蛏选择育种及亲本挑选中,壳长和壳宽是最主要的测量指标.

To evaluate the effects of phenotypic characters on the body weight in Solen grandis, 9 phenotypic characters and body weight were measured in 63 randomly sampled S. grandis individuals. With this dataset the correlation and path analysis were conducted. The results showed that the body weight was significantly or positively correlated with the selected phenotypic traits （ in all cases P 〈 0. 01 ）. Shell length showed the most direct but the least indirect effects on the body weight. The direct effect of shell length or shell width were more significant than their respective indirect effect. The indirect effect of any other phenotypie trait on the body weight, mostly through shell length and shell width, was lar- ger than direct one. The determination coefficient reveals that .Y.d = 0. 933 〉 0. 850, showing that these traits were critical in the explanation of body weight. Shell length had the largest determination coefficient on the live body weight （ di = 0. 827 1 ） , while shell length and shell width had the largest determination coefficient （ dij = 0. 580 9 ） in terms of code- termining coefficient. We established a multiple regression equation Y = - 56. 969 ＋ 0. 282X1 ＋ 2. 601X2 ＋ 0. 997 X6 - 0. 191X9. This work suggested in selective breeding and parents selecting of S. grandis, the shell length and width were most important indicative traits.