Rapid evolution of an invasive plant
Rapid evolution of an invasive plant
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DOI：
10.1890/03-4027
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发表时间：
2004-05-01
影响因子：
6.1
通讯作者：
Beardsley, P
中科院分区：
文献类型：
--
作者：
Maron, JL;Vila, M;Beardsley, P
外来植物常常面临与本土植物不同的条件。外来物种如何应对新范围内的陌生环境这一普遍问题尚不清楚。表型可塑性历来被视为首要的。使外来物种能够在大片、环境多样化的地区殖民的机制。然而，新的研究表明外来物种可以快速进化，这表明当代进化在入侵生态学中可能比以前认为的更重要。确定当代进化的影响；为了研究表型可塑性以及影响引入植物表型变异的创始人效应，我们比较了从欧洲本土采集的圣约翰草（贯叶连翘）的大小、繁殖力和叶面积，并在华盛顿、加利福尼亚、西班牙和瑞典的普通花园中引入了北美西部和中部种群。我们还通过检查扩增片段长度多态性 (AFLP) 标记的变异来确定这些植物之间的遗传关系。引入的种群之间存在显着的遗传变异，并且有证据表明穿叶穿孔素多次引入北美。在普通花园中，引进的植物并不普遍比本地植物更大，也并不多产。然而，在常见的花园中，引入的种群和本地种群在大小和繁殖力方面都表现出显着的纬度谱系。引进人群的谱系与本地人群的谱系大体趋同。当在华盛顿和瑞典的北纬地区花园中种植时，来自北纬地区的引进植物和本地植物通常表现优于来自南纬地区的植物。相反，来自南部纬度的植物在西班牙和加利福尼亚州的南部花园中表现最好。然而，不同花园之间叶面积的临床模式并没有变化。在华盛顿和加利福尼亚州这两个花园中，来自北纬地区的欧洲和中北美植物比来自南纬地区的植物有更大的叶子，这两个花园测量了这一性状。引入的植物并不总是出现在与其最密切相关的本地祖先相似的纬度上，这表明预适应（即气候匹配）不太可能是引入种群中临床模式的唯一解释。相反，结果表明，引入的植物正在进化适应其引入范围内的大范围环境条件。
Exotic plants often face different conditions from those experienced where they are native. The general issue of how exotics respond to unfamiliar environments within their new range is not well understood. Phenotypic plasticity has historically been seen as the primary. mechanism enabling exotics to colonize large, environmentally diverse areas. However, new work indicates that exotics can evolve quickly, suggesting that contemporary evolution may be more important in invasion ecology than previously appreciated. To determine the influence of contemporary evolution; phenotypic plasticity, and founder effects in affecting phenotypic variation among introduced plants, we compared the size, fecundity, and leaf area of St. John's wort (Hypericum perforatum) collected from native European and introduced western and central North American populations in common gardens in Washington, California, Spain, and Sweden. We also determined genetic relationships among these plants by examining variation in amplified fragment length polymorphism (AFLP) markers.There was substantial genetic variation among introduced populations and evidence for multiple introductions of H. perforatum into North America. Across common gardens introduced plants were neither universally larger nor more fecund than natives. However, within common gardens, both introduced and native populations exhibited significant latitudinally based clines in size and fecundity. Clines among introduced populations broadly converged with those among native populations. Introduced and native plants originating from northern latitudes generally outperformed those originating from southern latitudes when grown in northern latitude gardens of Washington and Sweden. Conversely, plants from southern latitudes performed best in southern gardens in Spain and California. Clinal patterns in leaf area, however, did not change between gardens; European and central North American plants from northern latitudes had larger leaves than plants from southern latitudes within these regions in both Washington and California, the two gardens where this trait was measured. Introduced plants did not always occur at similar latitudes as their most closely related native progenitor, indicating that pre-adaptation (i.e., climate matching) is unlikely to be the sole explanation for clinal patterns among introduced populations. Instead, results suggest that introduced plants are evolving adaptations to broad-scale environmental conditions in their introduced range.