Invasive and native populations of common ragweed exhibit strong tolerance to foliar damage
Invasive and native populations of common ragweed exhibit strong tolerance to foliar damage
复制标题
DOI：
10.1016/j.baae.2012.10.007
复制
发表时间：
2013-01-01
影响因子：
3.8
通讯作者：
Laitung, B.
中科院分区：
文献类型：
--
作者：
Gard, B.;Bretagnolle, F.;Laitung, B.
耐受性和抗性是植物为科普食草动物造成的损害而进化出的防御策略。引入外来物种到一个新的地理范围可能会改变植物草食动物的相互作用，并诱导新的植物防御策略与修改资源分配的选择压力。为了检测在普通豚草草食动物的耐受性的演变，我们比较了3个本地（北美）和3个引进（法国）人口，生长在一个共同的花园环境。探讨了叶类取食对植物营养和繁殖性状的影响。用手将植物脱叶，通过去除每个叶片的0%、50%或90%来模拟不同程度的昆虫放牧。总干生物量和地上部干生物量没有受到影响，而根干生物量和根冠比显着下降，本地和引进人口。此外，落叶处理并不影响任何植物繁殖性状的测量。因此，常见的豚草表现出有效的重新分配资源的地上部生物量的代价根落叶后，这使得该物种能够容忍草食动物没有明显的成本健身。我们没有发现引进和本地种群之间的植食性耐受性有任何差异，但显着差异被发现在繁殖与入侵种群产生更多的种子比本地种群。因此，在引进的植物种群中保持了对食草动物的耐受性。我们讨论了这些初步结果的生物防治策略，致力于共同豚草的一些影响。
Tolerance and resistance are defence strategies evolved by plants to cope with damage due to herbivores. The introduction of exotic species to a new biogeographical range may alter the plant herbivore interactions and induce selection pressures for new plant defence strategies with a modified resource allocation. To detect evolution in tolerance to herbivory in common ragweed, we compared 3 native (North America) and 3 introduced (France) populations, grown in a common garden environment. We explored the effect of leaf herbivory on plant vegetative and reproductive traits. Plants were defoliated by hand, simulating different degrees of insect grazing by removing 0%, 50% or 90% of each leaf blade. Total and shoot dry biomasses were not affected by increasing defoliation, whereas root dry biomass and root:shoot ratio decreased significantly for native and introduced populations. Furthermore, defoliation treatments did not affect any of the plant reproductive traits measured. Hence, common ragweed displayed an efficient reallocation of resources in shoot biomass at the expense of roots following defoliation, which allows the species to tolerate herbivory without obvious costs for fitness. We did not detect any difference in herbivory tolerance between introduced and native populations, but significant differences were found in reproduction with invasive populations producing more seeds than native populations. As a result, tolerance to herbivory has been maintained in the introduced plant populations. We discuss some implications of these preliminary results for biological control strategies dedicated to common ragweed.