俄罗斯鲟早期生长性状遗传参数的估计

采用人工授精技术和家系标准化培育技术构建了30个俄罗斯鲟(Acipenser gueldenstaedtii)父系全同胞家系(包含6个母系半同胞组),培育至150日龄和410日龄时,分别从每个家系中随机测量50尾个体的体长和体重。利用ASReml软件进行方差组分的估计,应用多性状动物模型进行俄罗斯鲟生长性状遗传参数的估计。结果表明,150日龄俄罗斯鲟体长和体重的遗传力分别为0.16±0.055、0.18±0.058,410日龄俄罗斯鲟体长和体重的遗传力分别为0.18±0.070、0.094±0.049,不同日龄生长性状的遗传力均为低遗传力,表明俄罗斯鲟更适合大规模家系的育种方法;150日龄和410日龄俄罗斯鲟体长和体重2个生长性状的表型相关和遗传相关均为高度正相关,其中表型相关系数分别为0.91、0.85,遗传相关系数分别为0.62、0.57,说明对体重或体长进行选育,均能实现改良生长性状的目标;不同日龄俄罗斯鲟家系平均体重的平均变异系数高于平均体长,前者为29.09%、29.46%,后者为10.16%、8.43%,表明俄罗斯鲟体重性状更具选育潜力。本研究估测了俄罗斯鲟不同时期生长性状的遗传参数,旨在为下一步合理制定该物种育种方案提供参考依据。

Estimates of genetic growth trait parameters during early develop- ment of Acipenser gueldenstaedtii

Thirty full-sib families including six maternal half-sib Acipenser gueldenstaedtii families were built using artificial insemination. The families were spawned on the same day, and a standardized procedure was used to produce the families during larval rearing to eliminate spawning age and common environmental effects on traits to increase precision of the estimate. Fifty individuals of each family were sampled randomly on days 150 and 410, and A. gueldenstaedtii body weight and body length were measured. The variance component and genetic parameters of body weight and body length were estimated with a multi-trait animal model using ASReml software. The heritability estimates on day 150 were 0.16±0.055 for body length and 0.18±0.058 for body weight. The heritability estimates on day 410 were 0.18±0.070 for body length and 0.094±0.049 for body weight. Heritabilities at different growth stages were low, suggesting that mass family selection is necessary for further selective breeding of A. gueldenstaedtii. The estimates of phenotypic and genetic correlation coefficients between the two traits at different stages were highly positive and were 0.91, 0.85, 0.62, and 0.57, respectively. A difference in the degree of correlation was observed between the two traits. A correlation analysis of genetic parameters would quantify the relationships between growth traits and facilitate planning of a multi-traits breeding program. These results suggest that growth traits of A. gueldenstaedtii could be improved by selecting either body weight or body length. The coefficients of variation for body weight at the two growth stages were 29.09% and 9.46% and both were higher than those for body length, which were 10.16% and 8.43%. These results indicate that the selection potential for body weight was higher than that for body length and provide a theoretical basis for the next A. gueldenstaedtii breeding program.