Summary
Many widespread invasive plant species express high phenotypic variation across novel environments, providing a unique opportunity to examine ecological and evolutionary dynamics under global change. However, studies often lack information about the origin of introduced populations, limiting our understanding of post-introduction evolution.
We assessed the responses of Reynoutria japonica from 128 populations spanning latitudinal transects in the native (China and Japan), and introduced (North America and Europe) ranges when grown in two common gardens.
Plants from introduced populations differed in almost all traits from those from Chinese populations, but were similar to plants from the putative origin in Japan. Compared to Chinese populations, North American, European and Japanese populations expressed lower trait values and plasticity in most traits. However, plants from both introduced and Japanese populations expressed higher clonality and plasticity in clonality than plants from Chinese populations. Further, introduced populations expressed higher plasticity in clonality but lower plasticity in basal diameter compared to Japanese populations.
Our findings emphasize the potential role of clonality and plasticity in clonality for invasion success. In addition, our study highlights the importance of comparisons to source populations within the native range to identify evolutionary responses of introduced plants to novel environments.
摘要
许多广泛扩散的入侵植物在新环境中表现出较高的表型变异，这为我们在全球变化背景下研究其生态与进化动态提供了独特的机会。然而，诸多研究往往缺乏引入种群来源的背景信息，因而限制了我们对其引入后进化过程的认识。
本研究中，我们沿纬度梯度收集了原产地(中国和日本)和引入地(北美洲和欧洲)的128个虎杖(Reynoutria japonica)种群， 比较了其在两个同质园中的生长表现和可塑性。
我们发现来自引入地的种群在几乎所有性状表现上均与中国种群存在差异，但与推定的起源地日本种群相似。与中国种群相比，北美、欧洲和日本种群的大多数性状表现出较低的性状值和可塑性。然而，引入地种群和日本种群在克隆性及其可塑性方面表现出高于中国种群的水平。此外，引入地种群的克隆可塑性也高于日本种群，但基径可塑性低于日本种群。
我们的研究结果表明，克隆性及其可塑性对外来植物入侵成功可能发挥着关键作用。此外，我们的研究也强调了将引入地种群与原产地源种群进行生物地理学比较的重要性，只有这样才能理解外来植物引种后对新环境的进化响应。
