Norwegian Institute for Nature Research (NINA), P.O. Box 5685 Torgarden, 7485, Trondheim, Norway.
Norwegian Veterinary Institute, P.O. Box 5695 Torgarden, 7485, Trondheim, Norway.
Nat Commun. 2019 Jan 14;10(1):199. doi: 10.1038/s41467-018-08021-z.
Stocking of hatchery produced fish is common practise to mitigate declines in natural populations and may have unwanted genetic consequences. Here we describe a novel phenomenon arising where broodstock used for stocking may be introgressed with farmed individuals. We test how stocking affects introgression in a wild population of Atlantic salmon (Salmo salar) by quantifying how the number of adult offspring recaptured in a stocked river depend on parental introgression. We found that hatchery conditions favour farmed genotypes such that introgressed broodstock produce up to four times the number of adult offspring compared to non-introgressed broodstock, leading to increased introgression in the recipient spawning population. Our results provide the first empirical evidence that stocking can unintentionally favour introgressed individuals and through selection for domesticated genotypes compromise the fitness of stocked wild populations.
养殖鱼类的存池是减轻自然种群减少的常见做法，但可能会产生意想不到的遗传后果。在这里，我们描述了一种新出现的现象，即用于存池的亲鱼可能与养殖个体发生基因渗入。我们通过量化在一个养殖的大西洋鲑（Salmo salar）种群中，有多少成年后代被重新捕获来检测存池对基因渗入的影响，以此来研究存池如何影响野生种群的基因渗入。我们发现，养殖条件有利于养殖基因型，以至于与未基因渗入的亲鱼相比，基因渗入的亲鱼产生的成年后代数量最多可达四倍，从而导致受纳产卵群体的基因渗入增加。我们的研究结果首次提供了经验证据，表明存池可能会无意中选择基因渗入个体，并通过选择驯化基因型来损害存池野生种群的适应性。
