Increased genetic variation and evolutionary potential drive the success of an invasive grass
Increased genetic variation and evolutionary potential drive the success of an invasive grass
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DOI：
10.1073/pnas.0607324104
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发表时间：
2007-03-06
影响因子：
11.1
通讯作者：
Molofsky, Jane
中科院分区：
文献类型：
--
作者：
Lavergne, Sebastien;Molofsky, Jane
尽管入侵物种的生物和经济影响越来越大，但对有利于引入物种的地理范围扩展和入侵性进化的进化机制知之甚少。在这里，我们重点介绍了入侵的湿地草。并记录了欧洲不同地区的遗传物质多次不受控制地引入北美所导致的进化后果。在欧洲范围内发生的大陆规模的遗传变异已经在北美引入的种群中重新洗牌和重组，产生了一些新的基因型。这一过程缓解了整个芦苇金丝雀草引进范围内的遗传瓶颈，包括在外围种群中，预计遗传多样性将耗尽，并在本地范围内观察到。此外，草芦在入侵区的遗传多样性和可遗传的表型变异比原生区高。由此产生的高进化潜力的入侵种群允许快速选择具有较高的营养定植能力和表型可塑性的基因型。我们的研究结果表明，重复引进一个单一的物种可能会无意中创造具有高适应潜力的有害入侵者。这些入侵物种可能会随着气候变化而进化，从而在未来对当地社区和生态系统产生越来越大的影响。更一般地说，多个移民事件，从而可能触发未来的适应和地理传播的物种种群，防止遗传瓶颈和通过重组产生遗传新奇。
Despite the increasing biological and economic impacts of invasive species, little is known about the evolutionary mechanisms that favor geographic range expansion and evolution of invasiveness in introduced species. Here, we focus on the invasive wetland grass Phalaris arundinacea L. and document the evolutionary consequences that resulted from multiple and uncontrolled introductions into North America of genetic material native to different European regions. Continental-scale genetic variation occurring in reed canarygrass' European range has been reshuffled and recombined within North American introduced populations, giving rise to a number of novel genotypes. This process alleviated genetic bottlenecks throughout reed canarygrass' introduced range, including in peripheral populations, where depletion of genetic diversity is expected and is observed in the native range. Moreover, reed canarygrass had higher genetic diversity and heritable phenotypic variation in its invasive range relative to its native range. The resulting high evolutionary potential of invasive populations allowed for rapid selection of genotypes with higher vegetative colonization ability and phenotypic plasticity. Our results show that repeated introductions of a single species may inadvertently create harmful invaders with high adaptive potential. Such invasive species may be able to evolve in response to changing climate, allowing them to have increasing impact on native communities and ecosystems in the future. More generally, multiple immigration events may thus trigger future adaptation and geographic spread of a species population by preventing genetic bottlenecks and generating genetic novelties through recombination.