The Arctic charr breeding programme has been a main driving force for developing the aquaculture industry in Sweden. Selection has been performed for almost 40 years using animals from a closed breeding nucleus. The aim of the current study was to evaluate the potential of further improving growth-related traits taking into account the existence of genotype-by-environment interaction. Furthermore, we investigated the magnitude of the genetic component associated with survival to the eyed stage and potential associations with inbreeding coefficients. A preliminary heritability estimate of 0.23 (SE 0.20) was obtained for survival to the eyed stage using records spanning from 2000 to 2017 (n = 230). Moreover, moderate-to-high heritability estimates (0.27-0.49) were obtained for growth-related traits (body weight and length), using animals from the latest generation of selection (year class 2017). Those animals (n = 2,776), originating from 55 full-sib families, were split into two groups and reared in separate land-based facilities of commercial fish farms in Sweden. The growth-related traits were recorded twice in both sites when animals were of >1 and >2 years of age. Existence of sexual growth dimorphism was indicated with the males having on average 6%-8% higher total length and 22%-34% higher body weight. Furthermore, high genetic correlations regarding growth traits were obtained amongst animals reared at the two different sites (0.82-0.95). In addition, we assessed the accuracy of best linear unbiased prediction (BLUP)-derived estimated breeding values (EBVs) when phenotypes from each rearing site were subsequently masked and used as a validation set. A mean prediction accuracy of 0.60 (length) and 0.64 (weight) were derived for both rearing sites. Overall, our results suggest that further growth improvements should be possible in the subsequent generations of selection. Finally, even though indications for the existence of an underlying genetic component(s) involved in survival to the eyed stage were obtained additional data will be required for elucidating its magnitude.

中文翻译：

---

评估选择性繁殖的北极红点鲑（Salvelinus alpinus）提高生长和存活到眼期的潜力

北极红点鲑育种计划一直是瑞典发展水产养殖业的主要推动力。近 40 年来一直使用来自封闭育种中心的动物进行选择。当前研究的目的是评估进一步改善生长相关性状的潜力，同时考虑到基因型与环境相互作用的存在。此外，我们调查了与存活到眼期相关的遗传成分的大小以及与近交系数的潜在关联。使用 2000 年至 2017 年的记录（n = 230）获得了存活至眼期的初步遗传力估计值为 0.23 (SE 0.20)。此外，获得了与生长相关的性状（体重和身长）的中到高遗传力估计值（0.27-0.49），使用最新一代选择的动物（2017 年级）。这些动物 (n = 2,776) 来自 55 个全同胞家庭，被分成两组，分别在瑞典商业养鱼场的陆基设施中饲养。当动物大于 1 岁和大于 2 岁时，在两个地点都记录了两次与生长相关的性状。雄性的总长度平均高 6%-8%，体重平均高 22%-34%，表明存在性生长二态性。此外，在两个不同地点饲养的动物之间获得了关于生长性状的高遗传相关性 (0.82-0.95)。此外，当每个饲养地点的表型随后被掩盖并用作验证集时，我们评估了最佳线性无偏预测 (BLUP) 衍生的估计育种值 (EBV) 的准确性。两个饲养场的平均预测精度为 0.60（长度）和 0.64（重量）。总的来说，我们的结果表明，在后续的选择中应该有可能进一步改善生长。最后，即使获得了与眼睛阶段存活有关的潜在遗传成分存在的迹象，但仍需要额外的数据来阐明其重要性。