大口黑鲈生长性状的遗传参数和育种值估计

采用最佳线性无偏差预测法(BLUP法)对大口黑鲈(Micropterus salmoides)体质量、体长和体高的遗传参数和育种值进行估计.4月龄和6月龄的体质量遗传力分别为0.29±0.08和0.28±0.10、体长遗传力分别为0.31±0.08和0.26±0.10,6月龄的体高遗传力为0.29±0.10.这些性状的传力都属于中度遗传力(P＜0.01),表明在加性效应控制下,大口黑鲈生长性状具有较大的遗传改良潜力.6月龄的体质量与体长、体质量与体高及体长与体高的遗传相关分别为0.790±0.094、0.820±0.081和0.990±0.001,这些性状之间均表现为高的正遗传相关性(P＜0.01),说明在对体质量进行选择的同时,其他生长性状也可以获得相应的间接选择反应.从不同评定方法的秩相关来看,6月龄时综合育种值与体质量育种值、体长育种值以及体质量育种值与体长育种值的秩相关系数均达到了极显著(P＜0.01),分别为0.998、0.914和0.890,用综合育种值对大口黑鲈的评定名次排序与用单性状育种值排序的差异不大.本研究对大口黑鲈生长性状的遗传参数和育种值进行确定与分析,旨在为该物种的人工选育提供理论依据和技术参考.

Estimation of parameters and breeding values for growth traits of largemouth bass

The genetic parameters and breeding values for growth traits (including body weight, body length, and body height) of the largemouth bass (Micropterus salmoides) were estimated using the best linear unbiased prediction (BLUP) method. At four months of age, the heritability was 0.29±0.08 for body weight and 0.31±0.08 for body length; at six months of age, heritability was 0.28±0.10 for body weight, 0.26±0.10 for body length, and 0.29±0.10 for body height. These heritabilities indicated that there was a great potential for selective breeding in the growth traits of largemouth bass. At four and six months of age, the genetic correlations between body weight and body length were 0.750±0.082 and 0.790±0.094, respectively. At six months, the genetic correlation was 0.820±0.081 between body weight and body height and 0.990±0.001 between body length and body height. These genetic correlations indicated that selection for body weight would result in positive responses in other traits. Correlation analysis of different estimated breeding values (EBVs), at four and six months, gave correlation coefficients of 0.923 and 0.919 between comprehensive EBV and weight EBV, 1.000 and 0.998 between comprehensive EBV and length EBV, and 0.914 and 0.890 between weight EBV and length EBV, respectively. These correlation coefficients showed that there was little difference in ranking for largemouth bass when using comprehensive EBV compared to one-trait EBV. The above parameters and breeding value results provide a theoretical basis and technical reference for the selective breeding for largemouth bass.