大菱鲆不同进口群体杂交后代的早期生长差异

Growth of the juvenile hybrids from different crossing combinations of the imported Scophthalmus maximus L.

2003-2005年间，分5批收集不同批次进口的大菱鲆群体，从各群体中挑选性腺发育良好的个体，利用人工授精技术，通过不平衡巢式交配设计，构建了5种杂交组合，测试其杂交子一代生长性能，为培育优良的大菱鲆养殖新品种提供基础资料。5个杂交组合共生产31个家系，在初孵仔鱼第25天和第80天，从每个家系随机取样50尾，测定其体长、体重等性状值，计算各杂交组合和家系25～80d的绝对增重率，通过方差分析、聚类分析比较各组合、家系间的生长性能的差异，并对不同家系25d和80d的体长体重相关性进行了分析。结果表明：杂交组合25d、80d体重性状间存在较大变异，80d体重LSD多重比较显示丹麦与法国进口群体的杂交组合（D×F）子一代生长优于其它杂交组合。系统聚类分析表明，丹麦×智利（D×C）组合与丹麦×法国（D×F）组合生长性能较为接近聚为一类，丹麦×西班牙（D×S）组合、丹麦×英国（D×E）组合和英国×西班牙（E×S）3个组合聚为一类，且前者的生长速度高于后者。家系间生长性能聚类分析表明，生长速度最快的家系分布在不同的杂交组合，80d体重的组合内家系间方差分析也表明组合内家系间存在较大变异。组合间和家系间生长分析发现大部分组合和家系在25d和80d的体长、体重性状值排序上不一致。家系相关分析表明，25d体长、体重与80d体长、体重间相关系数（0．132、0．096）和决定系数（0．017、0．009）均较小，25d体长体重对80d体长体重的影响甚微。

Five batches of turbot, Scophthalmus maxinuLs L., imported from 2003 to 2005 was collected to initiate the genetic breeding program. The five batches of turbot were Spain （S）, Chile （C）, Denmark （D）, England （E） and France （F） respectively. The unbalanced nest design was adopted and five cross combinations （thirty one full-sib families） were obtained by in vitro fertilization. Sample of fifty individuals was randomly collected from each family, and body length （cm） and the body weight （g） of fry on 25 days and 80 days were analysed by variance analysis, correlation analysis and cluster analysis. The results showed that there was significant difference in body weight of fry on 25 days and 80 days. Least-significant difference for comparisons of multi-average in body weight showed the fastest growth rate occured in the cross between the Danish batch and the French batch. The results of the cluster analysis indicated that five cross combinations could be divided into two groups. The first group including two cross combinations （D×C and D×F） was better than the other groups including three cross combinations （D×S, D×E and E×S） on growth rate. The families with better growth rate were found in each cross and the ANOVA analysis for body weight showed it was significantly different among the cross combinations. The data sorting of body length and the body weight on 25 days and 80 days ranked different in most cross and families. The results of the correlation analysis showed that the correlation index （0.132, 0.096） and determination coefficients （0.017, 0. 009） were small between the body length and the body weight of fry on 25 days and 80 days. It was clear that the growth time gave slightly indirect effect on body weight from 25 days to 80 days. The early growth traits varied in different hybrids cross combinations of the imported turbot. The results of this study imply the need and efficiency for turbot genetic breeding, by hybridization and selection based on Best Linear Unbiased Prediction, for the imported Scophthalmus maximus L.