Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, 7001, Australia.
Blue Economy Cooperative Research Centre, PO Box 897, Launceston, TAS, 7250, Australia.
Genet Sel Evol. 2024 Sep 12;56(1):63. doi: 10.1186/s12711-024-00929-z.
A genotype-by-environment (G × E) interaction is defined as genotypes responding differently to different environments. In salmonids, G × E interactions can occur in different rearing conditions, including changes in salinity or temperature. However, water flow, an important variable that can influence metabolism, has yet to be considered for potential G × E interactions, although water flows differ across production stages. The salmonid industry is now manipulating flow in tanks to improve welfare and production performance, and expanding sea pen farming offshore, where flow dynamics are substantially greater. Therefore, there is a need to test whether G × E interactions occur under low and higher flow regimes to determine if industry should consider modifying their performance evaluation and selection criteria to account for different flow environments. Here, we used genotype-by-sequencing to create a genomic-relationship matrix of 37 Chinook salmon, Oncorhynchus tshawytscha, families to assess possible G × E interactions for production performance under two flow environments: a low flow regime (0.3 body lengths per second; bl s) and a moderate flow regime (0.8 bl s).
Genetic correlations for the same production performance trait between flow regimes suggest there is minimal evidence of a G × E interaction between the low and moderate flow regimes tested in this study, for Chinook salmon reared from 82.9 ± 16.8 g ( ± s.d.) to 583.2 ± 117.1 g ( ± s.d.). Estimates of genetic and phenotypic correlations between traits did not reveal any unfavorable trait correlations for size- (weight and condition factor) and growth-related traits, regardless of the flow regime, but did suggest measuring feed intake would be the preferred approach to improve feed efficiency because of the strong correlations between feed intake and feed efficiency, consistent with previous studies.
This new information suggests that Chinook salmon families do not need to be selected separately for performance across different flow regimes. However, further studies are needed to confirm this across a wider range of fish sizes and flows. This information is key for breeding programs to determine if separate evaluation groups are required for different flow regimes that are used for production (e.g., hatchery, post smolt recirculating aquaculture system, or offshore).
基因型与环境（G×E）互作是指不同基因型对不同环境的反应不同。在鲑鱼中，G×E 互作可能发生在不同的养殖条件下，包括盐度或温度的变化。然而，水流量是一个可以影响新陈代谢的重要变量，尽管生产阶段的水流量不同，但尚未考虑其潜在的 G×E 互作。鲑鱼产业现在正在通过在水箱中操纵水流来改善福利和生产性能，并在近海扩大海笼养殖，那里的水流动态要大得多。因此，有必要测试低流量和高流量条件下是否会发生 G×E 互作，以确定鲑鱼产业是否需要考虑修改其性能评估和选择标准，以适应不同的水流环境。在这里，我们使用基因型测序技术构建了 37 个奇努克鲑鱼（Oncorhynchus tshawytscha）家系的基因组关系矩阵，以评估在两种水流环境下生产性能的可能 G×E 互作：低流量环境（0.3 个体长每秒；bl s）和中流量环境（0.8 bl s）。
同一生产性能性状在不同水流条件下的遗传相关表明，在本研究中测试的低流量和中流量条件之间，奇努克鲑鱼从 82.9±16.8g（±s.d.）到 583.2±117.1g（±s.d.）生长时，几乎没有证据表明存在 G×E 互作。性状之间的遗传和表型相关估计没有显示任何不利于大小（体重和条件系数）和生长相关性状的性状相关，无论水流条件如何，但确实表明测量饲料摄入量将是提高饲料效率的首选方法，因为饲料摄入量和饲料效率之间存在很强的相关性，这与以前的研究一致。
这些新信息表明，奇努克鲑鱼家系不需要根据不同的水流条件分别进行性能选择。然而，还需要进一步的研究来确认这一点，以涵盖更广泛的鱼类大小和水流范围。这些信息对于确定是否需要为用于生产的不同水流条件（例如孵化场、后幼鱼再循环水产养殖系统或近海）建立单独的评估群体，对于繁殖计划来说是关键的。
