不同牙鲆群体遗传力和育种值分析

Analysis of heritability and breeding value of different stocks for Japanese flounder (Paralichthys olivaceus)

以牙鲆(Paralichthys olivaceus)抗病群体(RS)、RS(♂)与从日本引进的日本群体(♀)交配建立的群体(RJ)、日本群体(♂)与RS(♀)交配建立的群体(JR)、以及韩国群体(KS)为基础群体,通过随机交配建立牙鲆家系,研究了4个群体作为亲本的育种性能。待所建立的家系生长至19月龄左右时,测量家系生长性状,包括全长和体质量,测量所得数据用SPSS及DMU软件中的REML算法和BLUP方法进行分析。结果显示,从表型参数可以看出KS(♂)×RJ(♀)杂交后代表现出明显的生长优势。19月龄牙鲆全长和体质量的遗传力分别为0.301、0.295,都属于中等遗传力。因此,牙鲆群体具有较好的遗传改良潜力。全长、体质量育种值与其表型值的相关系数分别为0.838和0.827,且呈极显著相关(P<0.01),表明个体育种值的预测结果具有较高的准确性。对父母本分别进行育种值比较可知,父本中KS的育种值最高,母本中RJ的育种值最高,因此选用KS(♂)和RJ(♀)杂交可培育出生长迅速的牙鲆新品种。本研究通过比较4个资源群体牙鲆生长性状的育种性能,并以此作为筛选优良亲本群体的重要依据,旨在为牙鲆新品种的成功选育奠定理论基础,同时为牙鲆的进一步遗传改良提供重要的科学依据。

As an important mariculture species in China, the rapid development of breeding industry of Japanese flounder （Paralichthys olivaceus）, lead to the breeding of Japanese flounder facing more and more serious problems at present, such as growth rate depression, fertility declined, resistance recession etc. In order to keep Japanese flounder aquaculture developing healthy and sustainability, it is necessary to get fast-growing Japanese flounder by crossbreeding and selecting. In this paper, four base stocks of Japanese flounder （Paralichthys olivaceus）, including Resistance stock （RS）, Korea stock （KS）, Resistance Japanese stock （RJ）, Japanese Resistance stock （JR）, were used to crossbreed and establish Japanese flounder families. The total length and body weight of these families would be measured, when they were about 19 months old. The SPSS system was used to analysis the data, at first. And then, estimated breeding values （EBVs） and other genetic parameters of total length and body weight were estimated by DMU package, based on the method of REML （Restricted Maximum Likelihood） and BLUP （Best Linear Unbiased Prediction） procedure. Results showed that, the phenotypic value of crossbreed- ing combination, KS （♂） × RJ （♀）, was best among all the combinations. The heritabilities of Japanese flounder＇s total length and body weight were 0.301 and 0.295, respectively, both of which were medium heritability. The correlations coefficient of breeding value and phenotypic value of growth traits were 0.838 and 0.827; both phenotypes of total length and body weight were statistically highly significant （P〈0.01） correlated to their breeding values, respectively. That is to say, the prediction result of breeding value reasonable accuracy was perfect. Comparing the means of breeding value of all combinations, we selected KS as male and RJ as female to breeding new species, because the two has the best breeding value relative to sex. By this method, new Japanese flounder variety growing rapidly could be brood successfully.