Data from: Strong divergence in trait means but not in plasticity across hatchery and wild populations of sea-run brown trout Salmo trutta

There is ample evidence that organisms adapt to their native environment when gene flow is restricted. However, evolution of plastic responses across discrete environments is less well examined. We studied divergence in means and plasticity across wild and hatchery populations of sea-run brown trout (Salmo trutta) in a common garden experiment with two rearing environments (hatchery and a nearly natural experimental stream). Since natural and hatchery environments differ, this arrangement provides an experiment in contemporary adaptation across the two environments. A QST-FST approach was used to investigate local adaptation in survival and growth over the first summer. We found evidence for divergent selection in survival in one year and in body length in both years and rearing environments. In general, the hatchery populations had higher survival and larger body size in both environments. QST in body size did not differ between the rearing environments and constitutive divergence in the means was in all cases stronger than divergence in the plastic responses. These results suggest that in this system constitutive changes in mean trait values are more important for local adaptation than increased plasticity. In addition, ex-situ rearing conditions induce changes in trait means that are adaptive in the hatchery, but potentially harmful in the wild, suggesting that hatchery rearing is likely to be a sub-optimal management strategy for trout populations facing selection in the stream environment.已有充分证据表明，当基因流受限之时，生物会适应其原生栖息环境。然而，针对离散环境下可塑性响应的演化研究仍相对不足。我们借助设置两种饲养环境（人工孵化场环境与近自然实验溪流环境）的共同花园实验（common garden experiment），针对洄游褐鳟（*Salmo trutta*）的野生种群与孵化场种群，探究了其性状均值与可塑性的分化情况。鉴于自然环境与孵化场环境存在显著差异，该实验设计可用于开展两种环境下的当代适应性研究。本研究采用QST-FST分析法，针对首个夏季的存活与生长性状展开本地适应性探究。研究结果显示，单一年份的存活性状以及两年各饲养环境下的体长性状均存在分歧选择的证据。总体而言，孵化场种群在两种环境中均展现出更高的存活率与更大的个体体型。体型的QST值在不同饲养环境间并无显著差异，且所有情境下的均值固有分化均强于可塑性响应分化。上述结果表明，在本研究体系中，性状均值的固有变化对本地适应性的贡献，相较于可塑性提升更为关键。此外，迁地饲养条件会诱导产生一类在孵化场环境中具备适应性，但在野生环境中或具危害性的性状均值变化，这提示针对溪流环境中存在选择压力的鳟鱼种群，孵化场饲养或许并非最优的种群管理策略。