大菱鲆25日龄3个经济性状的遗传参数评估

Estimation of genetic parameters for three economic traits in 25d turbot fry

为估计我国引进大菱鲆群体的遗传学参数,2006年从多个大菱鲆养殖场采集源于不同国家和地区、不同进口批次的大菱鲆亲鱼,利用人工授精技术构建了66个全同胞家系,包括26个父系半同胞家系组。选用混合模型方程,通过约束最大似然法进行了方差、协方差、遗传力和遗传相关等估计。结果表明,大菱鲆25d仔鱼体长、存活率和白化率的遗传力分别为0.20、0.07和0.22;3个性状间呈负遗传相关关系,检验不显著。研究结果表明,大菱鲆体长和白化率是中度遗传力,选择育种潜力较大;3个性状任何性状的选择对其他两个性状的影响很小,利用一个性状对另一个性状的间接选择是不可行的。

Different batches of imported turbot Scophthalmus maximus L.,were collected from different fish farms as broodstock for a genetic breeding program in 2006.Twenty-six paternal half-sib families and sixty-six full-sib families were obtained by artificial fertilization.Variance,covariance matrix,heritability and genetic correlation were estimated by restricted maximum likelihood.The results showed that the heritability of body length,survivorship and albinism rate for 25 d fry were 0.20,0.07 and 0.22,respectively.There was no significant correlation between the three traits.The study revealed moderate heritability in body length and albinism rate and a relatively high potential for selective breeding.Selection of any one of the three traits had little effect on the others,indicating that indirect selection of these traits was unfeasible.