广西北部湾海域不同月龄施氏獭蛤(Lutraria sieboldii)形态性状对体质量的相关性和通径分析

Correlation and Path Analysis of Morphological Characters of Lutraria sieboldii at Different Months of Age on Body Mass in Beibu Gulf of Guangxi

为确定不同月龄施氏獭蛤形态性状与体质量之间的关系,随机选取施氏獭蛤3月龄(13.83 ± 4.25 mm)、6月龄(33.21 ± 4.53 mm)各200个样本和24月龄(94.17 ± 8.50 mm) 98个样本,采用多元回归分析和通径分析研究对体质量的影响。使用偏相关性检验和方差膨胀系数排除对体质量影响不显著的性状和存在多元共线性的性状,采用逐步回归的方法分别构建施氏獭蛤3月龄、6月龄和24月龄体质量的线性回归方程。回归分析结果显示,除24月龄贝壳高外,各月龄贝表型性状均显著或极显著影响体质量。通径分析结果显示,壳长对3月龄稚贝和24月龄贝体质量影响最大,壳宽对6月龄贝体质量影响最大,各月龄贝的总决定系数(R2)均大于0.85。不同月龄施氏獭蛤形态性状对体质量的回归方程如下,3月龄贝:W3 = −0.744 + 0.027SH,R2 = 0.916;6月龄贝:W6 = −9.217 + 0.185SL + 0.128SH + 0.535SW,R2 = 0.853;24月龄贝:W24 = −212.727 + 1.872SL + 2.748SW,R2 = 0.850。广西北部湾海域施氏獭蛤不同月龄各形态性状对体质量影响不同,以施氏獭蛤体质量为选育目标时,3月龄贝应以壳高为选择性状,6月龄贝以壳宽为主选择性状同时兼顾壳高,24月龄贝以壳长为主选择性状,壳宽为辅助选择性状。研究结果为广西北部湾海域施氏獭蛤苗种培育和亲贝挑选提供了基础的资料。To understand the relationship between morphological traits and body weight in different months of age, we randomly selected 200 samples at 3 months (13.83 ± 4.25 mm), 200 samples at 6 months (33.21 ± 4.53 mm) and 98 samples at 24 months (94.17 ± 8.50 mm) to study the effects of multiple regression analysis and path analysis on body weight. Partial correlation test and variance expansion coefficient were used to exclude the characters with no significant effect on body weight and the characters with multiple collinearity. The linear regression equations of the body weight of L. sieboldii at 3 months, 6 months and 24 months were constructed by stepwise regression method. The results of regression analysis showed that the phenotypic traits of seashells at each month old had significant or extremely significant effects on body weight except the height of seashells at 24 months old. The results of path analysis showed that shell length had the greatest effect on the body weight of 3-month-old juveniles and 24-month-old juveniles, while shell width had the greatest effect on the body weight of 6-month-old juveniles. The total coefficient of determination (R2) of each month was greater than 0.85. The regression equation of morphological traits on body weight of L. sieboldii at different months of age was as follows: W3 = −0.744 + 0.027SH, R2 = 0.916;6-month-old shellfish: W6 = −9.217 + 0.185SL + 0.128SH + 0.535SW, R2 = 0.853;24-month-old shellfish: W24 = −212.727 + 1.872SL + 2.748SW, R2 = 0.850. Guangxi beibu gulf L. sieboldii different months each morphological characters influence on body quality is different, L. sieboldii body quality breeding goal, Shell height should be selected for 3-month-old shellfish. Shell width was the main selection trait of 6 month old shellfish, while shell height was also considered. Shell length was the main selection trait and shell width was the auxiliary selection trait in 24-month-old shellfish. The results provided basic data for the breeding and selection of parental shells in Beibu Gulf of Guangxi.