Herbivores can select for mixed defensive strategies in plants
Herbivores can select for mixed defensive strategies in plants
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DOI：
10.1111/nph.12023
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发表时间：
2013-01-01
期刊：
影响因子：
9.4
通讯作者：
Fornoni, Juan
中科院分区：
文献类型：
--
作者：
Carmona, Diego;Fornoni, Juan
抵抗力和耐受力是针对食草动物最重要的防御机制。最初的理论研究认为这两种机制在功能上是多余的，但最近的实证研究表明这些机制可能相互补充，有利于混合防御模式的存在。然而，耐受性和抗性之间存在冗余的预期仍然没有得到支持。在这项研究中，我们通过生态遗传学现场实验测试了这一假设，其中操纵了曼陀罗两种食草动物（曼陀罗和小花）的存在/不存在。在三种处理中的每一种中，都进行了基因型选择分析并比较了选择模式。我们的结果表明，两种食叶植物之间的抗性和耐受性选择存在显着差异。耐受性和抵抗性并不是 D. stramium 中多余的防御策略，而是作为针对两种甲虫物种的互补防御，有利于混合防御策略的进化。尽管每种食草动物都选择了不同的防御策略，但观察到的平均耐受性和抗性更接近针对 E. parvula 和两种甲虫共同预测的适应性峰值。在我们的实验群体中，食草动物施加的自然选择有利于植物中混合防御策略的进化，解释了中等水平的耐受性和抗性的存在。
Resistance and tolerance are the most important defense mechanisms against herbivores. Initial theoretical studies considered both mechanisms functionally redundant, but more recent empirical studies suggest that these mechanisms may complement each other, favoring the presence of mixed defense patterns. However, the expectation of redundancy between tolerance and resistance remains unsupported.In this study, we tested this assumption following an ecological genetics field experiment in which the presence/absence of two herbivores (Lema daturaphila and Epitrix parvula) of Datura stramonium were manipulated. In each of three treatments, genotypic selection analyses were performed and selection patterns compared.Our results indicated that selection on resistance and tolerance was significantly different between the two folivores. Tolerance and resistance are not redundant defense strategies in D. stramonium but instead functioned as complementary defenses against both beetle species, favoring the evolution of a mixed defense strategy. Although each herbivore was selected for different defense strategies, the observed average tolerance and resistance were closer to the adaptive peak predicted against E. parvula and both beetles together.In our experimental population, natural selection imposed by herbivores can favor the evolution of mixed defense strategies in plants, accounting for the presence of intermediate levels of tolerance and resistance.