Extending glacial refugia for a European tree: genetic markers show that Iberian populations of white elm are native relicts and not introductions
Extending glacial refugia for a European tree: genetic markers show that Iberian populations of white elm are native relicts and not introductions
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DOI：
10.1038/hdy.2013.81
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发表时间：
2014-02-01
期刊：
影响因子：
3.8
通讯作者：
Gil, L.
中科院分区：
文献类型：
--
作者：
Fuentes-Utrilla, P.;Venturas, M.;Gil, L.
保护政策通常侧重于就地保护本地种群，这一优先事项需要准确评估种群状况。对于那些自然栖息地已经变得既稀有又高度分散的物种来说，区分原生状态和引进状态可能特别困难（同时也是最重要的）。在这里，我们解决的地位，白色榆树（榆光），欧洲河岸树种的人口已被分割的人类活动，并保护无论它被认为是本土的。该物种的小种群位于伊比利亚，在那里它们是不受保护的，因为它们被认为是由于它们的稀有引进。然而，法国西南部的伊比利亚和邻近地区已被证明支持许多欧洲树木的离散冰川避难所种群，并且伊比利亚白色榆树是本地遗种的可能性仍然存在。我们使用叶绿体RFLP和核微卫星建立人口之间的关系，在伊比利亚和中欧核心分布。贝叶斯方法揭示了人口之间的显着空间结构。伊比利亚和法国西南部的物种具有中欧不存在的等位基因，并显示出伊比利亚内公认的本土分类群中常见的空间种群结构。伊比利亚人口显示了古代人口瓶颈的人口特征，而中欧人口则显示了近期人口瓶颈的特征。这些模式是不符合历史上引进的白色榆树伊比利亚，而不是强烈支持本土地位，主张立即实施的保护措施，白色榆树人口在西班牙和法国南部的毗连地区。
Conservation policies usually focus on in situ protection of native populations, a priority that requires accurate assessment of population status. Distinction between native and introduced status can be particularly difficult (and at the same time, is most important) for species whose natural habitat has become both rare and highly fragmented. Here, we address the status of the white elm (Ulmus laevis Pallas), a European riparian tree species whose populations have been fragmented by human activity and is protected wherever it is considered native. Small populations of this species are located in Iberia, where they are unprotected because they are considered introductions due to their rarity. However, Iberia and neighbouring regions in southwestern France have been shown to support discrete glacial refuge populations of many European trees, and the possibility remains that Iberian white elms are native relicts. We used chloroplast RFLPs and nuclear microsatellites to establish the relationship between populations in Iberia and the Central European core distribution. Bayesian approaches revealed significant spatial structure across populations. Those in Iberia and southwestern France shared alleles absent from Central Europe, and showed spatial population structure within Iberia common in recognized native taxa. Iberian populations show a demographic signature of ancient population bottlenecks, while those in Central European show a signature of recent population bottlenecks. These patterns are not consistent with historical introduction of white elm to Iberia, and instead strongly support native status, arguing for immediate implementation of conservation measures for white elm populations in Spain and contiguous areas of southern France.