Crossbreeding of three different shell color lines in the Pacific oyster reveals high heterosis for survival but low heterosis for growth
Crossbreeding of three different shell color lines in the Pacific oyster reveals high heterosis for survival but low heterosis for growth
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DOI：
10.1016/j.aquaculture.2020.735621
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发表时间：
2020-12-15
期刊：
影响因子：
4.5
通讯作者：
Kong, Lingfeng
中科院分区：
文献类型：
--
作者：
Han, Ziqiang;Li, Qi;Kong, Lingfeng
杂种优势是提高水产养殖生产性状的重要途径，但双壳贝类选育品系间的杂种优势尚不清楚。本研究以太平洋牡蛎黑壳（B，第7代）、白色壳（W，第7代）和橙子壳（O，第6代）品系为材料，进行了双列杂交，探讨了选育品系利用生产性状杂种优势的潜力。对27个全同胞家系的生长和存活进行了仔稚鱼期杂种优势和配合力分析，其中仔稚鱼期在荣成和乳山两个环境中进行了10个月的观察。幼鱼存活率和幼鱼生长量的方差中，特殊配合力方差占绝大部分，说明了非加性遗传效应（杂种优势）在各品系间的重要性。此外，所有正反交杂种表现出低或没有优势的生长在幼虫和少年阶段，但高优势的幼虫存活。这一发现表明，品系间杂交育种可以应用于提高孵化场的幼虫存活率。6个杂交组合中有4个组合在乳山表现为HPH阳性，在荣成表现为HPH阴性。乳山的高株高表明，可以进行线间杂交。在乳山地区具有较大的应用价值。此外，黑壳和白色壳品系的存活率通过与橙子壳品系杂交而得到改善。特别是杂交组合WO（W雌× O雄）可使纯种WW的成活率在幼虫期提高近130%，在幼鱼期提高近40%。本研究揭示了太平洋牡蛎选育系间的高存活杂种优势，为利用现有双壳贝类选育系间的非加性遗传效应提供了理论依据。
Heterosis is important for improving productive traits in aquaculture, but the heterosis between selected lines remains unclear in bivalve molluscs. Here, a diallel crosses among black shell (B, 7th generation), white shell (W, 7th generation) and orange shell (O, 6th generation) lines of the Pacific oyster were performed to examine the potential for exploiting heterosis of productive traits by crossbreeding of selected lines. Heterosis and combining abilities for growth and survival of 27 full-sib families were analyzed at both larval and juvenile stages, of which the juvenile stage was examined at two environments (Rongcheng and Rushan) for 10 months. The variance of specific combining ability accounts for the majority of the total variance for larval and juvenile survival and juvenile growth, which revealed the importance of non-additive genetic effects (heterosis) among these lines. Moreover, all reciprocal hybrids showed low or no heterosis for growth at both larval and juvenile stages, but a high heterosis for larval survival. This finding suggested that inter-line crossbreeding can be applied to improve the larval survival in hatcheries. Furthermore, four of six hybrid crosses showed positive HPH in Rushan but negative HPH in Rongcheng. The higher HPH at Rushan suggested that inter-line crossbreeding in C. gigas has more application value in Rushan. In addition, the survival of both black shell and white shell lines have been improved by crossing with the orange shell line. Especially, the hybrid cross WO (W female x O male) can improve the survival rate of purebred WW by nearly 130% at larval stage and nearly 40% at juvenile stage. Overall, this study reveals the high heterosis for survival among selected lines in the Pacific oyster, and will be helpful for the utilization of non-additive genetic effects among existing selected lines in bivalves.