Effective population size of steelhead trout: influence of variance in reproductive success, hatchery programs, and genetic compensation between life-history forms
Effective population size of steelhead trout: influence of variance in reproductive success, hatchery programs, and genetic compensation between life-history forms
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DOI：
10.1111/j.1365-294x.2006.03206.x
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发表时间：
2007-03-01
影响因子：
4.9
通讯作者：
Blouin, Michael S.
中科院分区：
文献类型：
--
作者：
Araki, Hitoshi;Waples, Robin S.;Blouin, Michael S.
在自然种群中，有效种群大小受多种生物学因素的影响。为了评估它们的相对重要性，我们估计了繁殖者的有效数量，每年（N-B）和有效的人口规模，每一代（N-E）在溯河产卵的虹鳟（Oncorhynchus mykiss）在胡德河，俄勒冈州（美国）。使用人口统计学数据和遗传亲子关系分析，对15年以上返回河流的所有成年人（> 15000人）的几乎完整的样本进行了分析，我们估计了13年的N-b和整整三代的N-e。结果如下：（i）N-e与估计的普查种群规模（N）的比值为0.17-0.40，个体间繁殖成功率的巨大差异是N-e/N降低的主要原因;（ii）来自传统孵化计划的鱼类（H-trad：非本地，孵化场中的多代）对N-b有负面影响，不仅通过降低平均繁殖成功率，而且通过增加繁殖亲本之间繁殖成功率的差异，而在补充剂孵化项目中没有发现这种影响的迹象（H-supp：本地，在孵化场单代）;（iii）N-b是相对稳定的运行年，尽管溯河产卵的成年人的年度运行大小波动很大。我们发现高水平的繁殖贡献nonanadromous父母溯河产卵的后代溯河产卵的运行大小是小的，这表明生活史形式（溯河产卵和nonanadromous）之间的遗传补偿。这是第一项研究表明，不同生活史形式之间的生殖相互作用可以缓冲波动的人口普查规模对N-e的遗传影响。
The effective population size is influenced by many biological factors in natural populations. To evaluate their relative importance, we estimated the effective number of breeders per year (N-b) and effective population size per generation (N-e) in anadromous steelhead trout (Oncorhynchus mykiss) in the Hood River, Oregon (USA). Using demographic data and genetic parentage analysis on an almost complete sample of all adults that returned to the river over 15 years (> 15 000 individuals), we estimated N-b for 13 run years and N-e for three entire generations. The results are as follows: (i) the ratio of N-e to the estimated census population size (N) was 0.17-0.40, with large variance in reproductive success among individuals being the primary cause of the reduction in N-e/N; (ii) fish from a traditional hatchery program (H-trad: nonlocal, multiple generations in a hatchery) had negative effects on N-b, not only by reducing mean reproductive success but also by increasing variance in reproductive success among breeding parents, whereas no sign of such effects was found in fish from supplementation hatchery programs (H-supp: local, single generation in a hatchery); and (iii) N-b was relatively stable among run years, despite the widely fluctuating annual run sizes of anadromous adults. We found high levels of reproductive contribution of nonanadromous parents to anadromous offspring when anadromous run size is small, suggesting a genetic compensation between life-history forms (anadromous and nonanadromous). This is the first study showing that reproductive interaction between different life-history forms can buffer the genetic impact of fluctuating census size on N-e.