以色列红罗非鱼与其他罗非鱼群体杂交子一代在海水中生长性能分析

The Growth Performance of the Hybridization Offspring of Israel Strain Red Tilapia and Other Tilapia Populations in Sea Water

中文关键词: 罗非鱼  家系  群体  遗传力  选育

英文关键词: Tilapia  Family  Population  Heritability  Selection

中文摘要:

      利用以色列红罗非鱼品系(Israel strain of red tilapia, R)、吉富品系(GIFT strain of Nile tilapia, J) (Oreochromis niloticus)、奥利亚罗非鱼(Blue tilapia, A) (O. aureus)、尼罗罗非鱼(Nile tilapia, N) (O. niloticus)等群体，构建了具有广泛遗传变异罗非鱼育种基础群体。采用人工定向交尾技术，获得了15个以色列红罗非鱼群体内和65个以色列红罗非鱼群体及其他群体间杂交全同胞家系。待家系平均体重5−8 g时进行标记，每个家系随机取样40尾标记个体放入养殖池中，采用逐渐提高盐度驯化至养殖盐度为28，养殖150 d后进行生长性能测试以及杂交和体重生长遗传参数分析。结果显示，在研究的所有群体内和群体间的交配组合中，以色列红罗非鱼品系(♀)与尼罗罗非鱼(♂)杂交的杂交组合(R×N)子一代生长速度最快，优于其他杂交组合，其平均体长、平均体重和绝对增重率分别为24.44 cm、385.23 g和4.94 g/d；ANOVA和LSD多重比较分析结果显示，杂交组合间在体长、体重指标上均达到差异极显著(P<0.01)，R×N与除J×R杂交组合外的其他3个杂交和1个群体自繁组子一代两两间存在显著差异(P<0.05)。利用实验构建的80个家系共2496个个体体重数据，考虑家系标记时的平均体重、池塘、雌、雄等因子，建立了遗传参数分析模型，估计体重的遗传力为0.46±0.07，属于中等遗传力。因此，利用本研究收集的罗非鱼基础群体，开展罗非鱼在海水中生长性状选育，具有很大的遗传改良潜力。

英文摘要:

      Brood stock was collected from Israel strains red tilapia, GIFT strain of Nile tilapia (Oreo¬chromis niloticus), Blue tilapia (O. aureus), and Nile tilapia (O. niloticus) to form a base population of tilapia with broad genetic variation. Using artificial oriented mating, we obtained 15 full-sib families by inbreeding within the Israel strain red tilapia population and 65 full-sib families from crossing filial generation between Israel strain red tilapia and other tilapia populations. The subjects were tagged when the mean body weight in a family was 58 g. Forty tagged individuals were randomly selected from each family and cultured in sea water with the salinity gradually increased to 28. After 150 days we measured the body length and the body weight of the subjects, and estimated the crossbreeding and genetic parameters of tilapia. Offspring of Israel strains red tilapia and Egyptian strain of Nile tilapia (R×N) showed the highest growth rate. The average body length, the average body weight and the absolute growth rate (AGR) of the first selected generation of R×N were 24.44 cm, 385.23 g and 4.94 g/d respectively. ANOVA analysis showed that there were significant differences (P<0.05) in the body length and the body weight. The multiple comparisons of LSD test in the body length and the body weight indicated that R×N were significantly different (P<0.05) from other three intercross populations (A×R, R×A, and R×J) and the self-reproducing population (RT), except for J×R. Based on the data of 2496 subjects from 80 full-sib groups of tilapia, we estimated the heritability of the body weight. The model was composed of different factors including the average body weight in the tagged family (covariate), tanks and sex effects, etc. The estimated heritability of the body weight was medium (0.46±0.07). Our results suggested that there was a great potential in the genetic improvement of tilapia through the selective breeding. This should provide the theoretical guidance for the mariculture and breeding of salt-tolerant strains of tilapia.