Population Genetics of Brook Trout in the Southern Appalachian Mountains
Population Genetics of Brook Trout in the Southern Appalachian Mountains
复制标题
DOI：
10.1002/tafs.10337
复制
发表时间：
2022-01-07
影响因子：
1.4
通讯作者：
King，Tim L.
中科院分区：
文献类型：
--
作者：
Kazyak，David C.;Lubinski，Barbara A.;King，Tim L.
在美国东部的特有范围内，对小溪鲑鱼遗传多样性的大范围模式仍然知之甚少。我们研究了从美国乔治亚州到加拿大魁北克省，再到西部五大湖区的836个种群中，22,020条小溪鲑鱼的12个微卫星座位的变异。与大西洋中部和东北部地区相比，阿巴拉契亚山脉南部的种群内多样性通常较低。阿巴拉契亚山脉南部的有效种群规模往往很小，许多人估计不到30只。位于阿巴拉契亚山脉南部的Brook Trout的种群遗传学远比传统上简单的“北方”和“南方”二分法所暗示的要复杂得多。当代种群遗传变异与来自密西西比河、大西洋中部和阿卡迪亚冰川避难所的小溪鲑鱼的地理扩张以及这些更广泛分支内的水系之间的分化是一致的。不同流域间的遗传变异显著(57.4%的总体变异发生在10位数的水文单位代码[HUC10]或更大的单位之间)，但即使在精细空间尺度上也是相当可观的(13%的变异发生在HUC12排水单位内的集合之间)。值得注意的是，87.2%的个体被正确分配到他们的起源集合中。虽然与现有主要孵化场的鱼进行比较表明，在一些种群中放养的影响，但遗传渗透并没有盖过种群遗传结构的大范围模式的信号。尽管我们的结果揭示了布鲁克特劳特在广阔的空间范围内的深层遗传结构，但细微规模的种群结构在阿巴拉契亚山脉南部普遍存在。我们的发现突出了阿巴拉契亚山脉南部许多小溪鲑鱼种群的特殊性和脆弱性，并对野生小溪鲑鱼的管理具有重要意义。为了方便保护从业者应用我们的发现，我们提供了一个互动的在线可视化工具，使我们的结果可以在与管理相关的尺度上进行探索。
Broad‐scale patterns of genetic diversity for Brook TroutSalvelinus fontinalisremain poorly understood across their endemic range in the eastern United States. We characterized variation at 12 microsatellite loci in 22,020 Brook Trout among 836 populations from Georgia, USA, to Quebec, Canada, to the western Great Lakes region. Within‐population diversity was typically lower in the southern Appalachian Mountains relative to the mid‐Atlantic and northeastern regions. Effective population sizes in the southern Appalachians were often very small, with many estimates less than 30 individuals. The population genetics of Brook Trout in the southern Appalachians are far more complex than a conventionally held simple “northern” versus “southern” dichotomy would suggest. Contemporary population genetic variation was consistent with geographic expansion of Brook Trout from Mississippian, mid‐Atlantic, and Acadian glacial refugia as well as differentiation among drainages within these broader clades. Genetic variation was pronounced among drainages (57.4% of overall variation occurred among 10‐digit hydrologic unit code [HUC10] units or larger units) but was considerable even at fine spatial scales (13% of variation occurred among collections within HUC12 drainage units). Remarkably, 87.2% of individuals were correctly assigned to their collection of origin. While comparisons with fish from existing major hatcheries showed impacts of stocking in some populations, genetic introgression did not overwhelm the signal of broad‐scale patterns of population genetic structure. Although our results reveal deep genetic structure in Brook Trout over broad spatial extents, fine‐scale population structuring is prevalent across the southern Appalachians. Our findings highlight the distinctiveness and vulnerability of many Brook Trout populations in the southern Appalachians and have important implications for wild Brook Trout management. To facilitate application of our findings by conservation practitioners, we provide an interactive online visualization tool to allow our results to be explored at management‐relevant scales.