罗氏沼虾形态性状对体长影响的通径分析

Path Analysis of Effects of Morphometric Traits on Body Length in Giant River Prawn Macrobrachium rosenbergii

为探究罗氏沼虾形态性状对体长的影响,随机选取391尾5月龄罗氏沼虾,对全长、体长、头胸甲长、头胸甲宽、第1腹节长、第2腹节宽等10个形态性状进行测量;经相关分析和通径分析,计算各性状指标间的相关系数、通径系数、决定系数和共同决定系数;选取通径系数达到显著水平的形态性状计算复相关指数,确定影响体长的重点性状;应用逐步回归分析方法建立形态性状估计体长的最优回归方程。试验结果表明,所测量形态性状与体长的相关系数均达到极显著水平(P<0.01);全长与体长相关系数、通径系数和决定系数均最大;回归方程的显著性检验结果显示,P<0.05,r^(2)=0.958,除第1腹节长、第2腹节高的偏回归系数为显著水平(P<0.05)外,其他性状的偏回归系数达到极显著水平(P<0.01)。由此可知,全长是影响体长的最重要性状,第2腹节宽、第6腹节宽对体长的直接作用极显著;将全长、第2腹节宽和第6腹节宽作为定向选育指标应用到建立罗氏沼虾快速生长专门化品系的生产实践中具有一定的理论依据。

In order to explore the effect of morphological characteristics of giant river prawn Macrobrachium rosenbergii on body length,391 individuals of five-month-old prawn were randomly sampled,ten morphometric characters such as total length,body length,carapace length,carapace width,first segment length and second segment width were measured.After correlation analysis and path analysis,the correlation coefficient,path coefficient,determination coefficient and common determination coefficient among various morphological traits were calculated;the morphological traits with significant path coefficients were selected to calculate the complex correlation index to determination the key morphological traits that affect body length;finally,the stepwise regression analysis equations for morphological traits were established to estimate body length.The results showed that the correlation coefficients between the measured morphological traits and body length had very significant level(P<0.01);the correlation coefficients between total length and body length,path coefficients,and determination coefficients were all the maximam;the regression coefficient of equations reached the significant level(P<0.05),r^(2)=0.958;except that the partial regression coefficients of the first segment length and second segment width were significant(P<0.05),the partial regression coefficients of other traits reached very significant levels(P<0.01).It was seen that the total length was the most important morphological trait that affected the body length.The second segment width and sixth width segment had significant direct effect on the body length;and total length,second segment width and sixth width segment as a directional breeding index,which were applied to the production practice of establishing a fast-growing specialized strain of giant river prawn.