九孔鲍生长性状的遗传力及其相关性分析

Estimates of Heritabilities and Genetic Correlations for Growth in Haliotis diversicolor supertexta

采用平衡巢式设计方法和人工授精技术,构建九孔鲍(Haliotis diversicolor supertexta)12个半同胞家系和36个全同胞家系(每个雄鲍配3个雌鲍),分别测定每个母系生长到8月龄的全同胞个体30个后代的壳长、壳宽和体质量,应用数量遗传学的全同胞组内相关分析法,利用SPSS软件的GLM过程计算表型变量的原因方差组分,估算九孔鲍8月龄生长性状的遗传力以及性状间遗传相关和表型相关。结果表明:利用父系半同胞组内相关法估计的遗传力是九孔鲍各生长性状遗传力的无偏估计值,其中壳长、壳宽和体质量性状的狭义遗传力的估计值分别为0.285、0.264和0.343,属于中高等遗传力,显示出较高的选择育种潜力;基于父系半同胞遗传协方差组分及表型协方差分别估计的各性状间的遗传相关和表型相关表明,各性状间均表现出高的正相关,其中壳长―壳宽、壳长―体质量和壳宽―体质量性状间遗传相关的相关系数分别为0.947、0.934、0.902,表型相关的相关系数分别为0.910、0.791、0.760。经t检验,各性状间遗传相关和表型相关均有统计学意义(P<0.01)。研究表明,以任何一个生长性状为参数进行选育,均可达到改良九孔鲍生长的效果。

Twelve half-sib families and thirty-six full-sib families were constructed by using methods of nest design and artificial insemination, in which each male mated three females. Thirty 8-month-old Haliotis diversicolor supertexta were measured for three growth traits including the body mass (BM), the shell length (SL), the shell width (BL). According to quantitative genetic theory, the heritability of each growth trait, and the genetic and phenotypic correlation among the traits were statistically studied by utilizing the method of variance and covariance analysis. The results showed that the heritability estimates in the narrow sense from intra-group correlation of paternal half-sib were precise and unbiased, and the heritability values for the above three traits were 0.285, 0.264 and 0.343, respectively. All of them belonged to moderate and high heritability, thus showing a high potential for selective breeding. The estimates of genetic correlation coefficients were 0.947, 0.934 and 0.902, respectively. The estimates of phenotypic correlation coefficients were 0.910, 0.791 and 0.760, respectively. The statistical significance (P<0.01) was detected by t-test among the three growth traits for both genetic and phenotypic correlation coefficients, indicating all the three traits may respond favorably to direct and indirect selection for growth.