Allelopathy confers an invasive Wedelia higher resistance to generalist herbivore and pathogen enemies over its native congener
Allelopathy confers an invasive Wedelia higher resistance to generalist herbivore and pathogen enemies over its native congener
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化感作用赋予入侵性蟛蜞菊比其本地同类对通才草食动物和病原体天敌具有更高的抵抗力
DOI：
10.1007/s00442-019-04581-z
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发表时间：
2020-02-01
期刊：
影响因子：
2.7
通讯作者：
Bonser, Stephen P.
中科院分区：
文献类型：
--
作者：
Qi, Shan-Shan;Liu, Yan-Jie;Bonser, Stephen P.
新防御假说预测，引进的植物可能具有新的化感化学物质，作为对本地多面手敌人的防御。本研究旨在通过对入侵植物三叶裂叶橐吾（Wedelia trilobata）的化感作用化学物质进行实验室对照研究，以确定三叶裂叶橐吾的化感作用化学物质是否能提高其对多种食草动物和病原菌的抗性。研究了三叶草叶提取物对多面虫的化感作用。结果表明，两种蛾的幼虫对中国白叶蛾的偏好高于三叶蛾。取食三叶木犀叶的幼虫生长速度显著低于取食中国木犀叶的幼虫。在离体叶片上接种病原菌后，三叶木犀叶的侵染面积显著小于中国木犀叶。此外，三叶曲叶提取物还能有效抑制病原菌的幼虫生长和菌丝生长。结果表明，外来入侵的三叶虫对一般食草动物和病原菌的防御能力强于本土同系物，这可能与化感作用有关。本研究提供了新颖的见解，可以全面联系新颖防御，行为约束和敌人释放假说。这些综合假设将解释入侵植物如何逃离它们的天然天敌，它们的化感化学物质可能会阻止食草昆虫并抑制病原体感染。
The Novel Defense Hypothesis predicts that introduced plants may possess novel allelochemicals which act as a defense against native generalist enemies. Here, we aim to test if the chemicals involved in allelopathy in the invasive plant Wedelia trilobata can contribute to higher resistance against generalist herbivore and pathogen enemies by comparing with its native congener W. chinensis in controlled laboratory conditions. The allelopathic effects of the leaf extract from W. trilobata on the generalist enemies were also assessed. We showed that the larvae of two moth species preferred W. chinensis over W. trilobata. The growth rate of larvae feeding on W. trilobata leaves was significantly lower than those feeding on W. chinensis leaves. When detached leaves were inoculated with phytopathogens, the infected leaf area of W. trilobata was significantly smaller than that of W. chinensis. In addition, the leaf extract of W. trilobata also effectively inhibited the growth of the larvae and the mycelial growth of the phytopathogens. Our results indicate that the defenses of invasive W. trilobata against generalist herbivore and pathogen enemies are stronger than that of its native congener, which may be attributed to the allelopathic effects. This study provides novel insights that can comprehensively link the Novel Defense, Behavioral Constraint and Enemy Release hypotheses. These combined hypotheses would explain how invasive plants escape from their natural specialist enemies, where their allelopathic chemicals may deter herbivorous insects and inhibit pathogen infection.