Red leaf margins indicate increased polygodial content and function as visual signals to reduce herbivory in Pseudowintera colorata
Red leaf margins indicate increased polygodial content and function as visual signals to reduce herbivory in Pseudowintera colorata
复制标题
DOI：
10.1111/j.1469-8137.2012.04063.x
复制
发表时间：
2012-04-01
期刊：
影响因子：
9.4
通讯作者：
Gould, Kevin S.
中科院分区：
文献类型：
--
作者：
Cooney, Luke J.;van Klink, John W.;Gould, Kevin S.
红色的叶缘很常见，但其功能意义尚不清楚。我们假设红叶边缘通过向食草性昆虫发出增加的化学防御的信号来减少叶片的食草性。叶片来自于一个自然种群。对边缘大小、草食危害、花色苷含量和多酚二醛(一种具有拒食特性的倍半萜二醛)的浓度进行了量化。在暗光、白光、绿光和红光下对红边和绿边的花叶草甲幼虫进行了取食试验，红边较宽的叶片含有较高浓度的多酚和花青素，引起的天然食草量较少。在白光下的试验中，斜纹夜蛾摄取的绿边叶片比红边叶片不成比例地多。在光照条件下，幼虫没有表现出取食偏好，从而削弱了叶片的颜色辨别能力。红叶边缘为花斑潜蝇提供了一种可靠而有效的化学防御视觉信号。斜纹夜蛾幼虫对叶缘的颜色作出感知和反应，而不是嗅觉信号。我们的研究为红叶的无色着色提供了直接的实验证据。
Red-pigmented leaf margins are common, but their functional significance is unknown. We hypothesized that red leaf margins reduce leaf herbivory by signalling to herbivorous insects the presence of increased chemical defences.Leaves were collected from a natural population of Pseudowintera colorata. Margin size, herbivory damage, anthocyanin content and concentrations of polygodial, a sesquiterpene dialdehyde with antifeedant properties, were quantified. Feeding trials involving larvae of Ctenopseustis obliquana, a generalist herbivore, were conducted on red- and green-margined P. colorata leaves in darkness, or under white, green or red light.Leaves with wider red margins contained higher concentrations of polygodial and anthocyanins, and incurred less natural herbivory. In trials under white light, C. obliquana consumed disproportionately more green- than red-margined leaf laminae. Larvae exhibited no feeding preference when light was manipulated such that leaf colour discrimination was impaired.Red leaf margins provide a reliable and effective visual signal of chemical defence in P. colorata. Ctenopseustis obliquana larvae perceive and respond to the colour of the leaf margins, rather than to olfactory signals. Our study provides direct experimental evidence for aposematic coloration in red leaves.