Rapid evolution of latitudinal clines in growth and defence of an invasive weed
Rapid evolution of latitudinal clines in growth and defence of an invasive weed
复制标题
入侵杂草生长和防御中纬度梯度的快速进化
作者：
Yang Y;Liu M;Pan Y;Huang H;Pan X;Sosa A;Hou Y;Zhu Z;Li B
在生长相关性状中重新建立可遗传的纬度倾斜系已被认为是入侵植物适应性进化的证据。我们在中国常见的园林中种植了14个阿根廷本地种群和14个中国引种的空心莲子草种群，并对这些种群的生长和防御机制进行了研究。研究了与生长和防御有关的性状的纬度梯度及其与试验地点和土壤氮素的可塑性，发现引进种群的化学防御能力随纬度的升高而降低，而本地种群的化学防御能力随纬度的升高而升高。在生长速率方面，引进种群的纬度梯度为正，而本地种群则不存在。总生物量/地上部生物量和比叶面积也存在平行的正纬向梯度。试验地点影响了生长速率、分支强度和三萜皂苷含量等纬度倾斜的发生或大小。引进种群比本地种群对实验地点和土壤氮的可塑性更大。我们为入侵植物在生长和防御方面的渐变群快速进化提供了证据。改变草食动物梯度和权衡之间的增长和防御可以解释非平行的渐变之间的本地和引进的范围。
Re‐establishment of heritable latitudinal clines in growth‐related traits has been recognised as evidence for adaptive evolution in invasive plants. However, less information is known about latitudinal clines in defence and joint clinal evolution of growth and defence in invasive plants.We planted 14 native Argentinean populations and 14 introduced Chinese populations ofAlternanthera philoxeroidesin replicate common gardens in China. We investigated the latitudinal clines of traits related to growth and defence, and plasticity of these traits in relation to experiment site and soil nitrogen.We found that chemical defence decreased with latitude in introduced populations but increased with latitude in native populations. For growth rate, latitudinal clines were positive in introduced populations but nonexistent in native populations. There were also parallel positive latitudinal clines in total/shoot biomass and specific leaf area. Experiment site affected the occurrence or magnitude of latitudinal clines in growth rate, branch intensity and triterpenoid saponins concentration. Introduced populations were more plastic to experiment site and soil nitrogen than native populations.We provide evidence for rapid evolution of clines in growth and defence in an invasive plant. Altered herbivory gradients and trade‐off between growth and defence may explain nonparallel clines between the native and introduced ranges.