The evolution of antiherbivore defenses and their contribution to species coexistence in the tropical tree genus Inga
The evolution of antiherbivore defenses and their contribution to species coexistence in the tropical tree genus Inga
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DOI：
10.1073/pnas.0904786106
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发表时间：
2009-10-27
影响因子：
11.1
通讯作者：
Coley, Phyllis D.
中科院分区：
文献类型：
--
作者：
Kursar, Thomas A.;Dexter, Kyle G.;Coley, Phyllis D.
植物和它们的食草动物构成了热带森林中一半以上的生物。因此，更好地了解植物防御草食动物的进化可能是我们理解热带生物多样性的核心。在这里，我们解决的进化，抗草食动物的防御和共存的新热带树属印加（豆科）的可能贡献。因加有超过300种，最近已经辐射，并经常是最多样化和丰富的属在一个给定的网站之一。对于来自巴拿马和秘鲁的37个物种，我们的特点是发育，蚂蚁和化学防御草食动物。我们发现了广泛的变化，防御，但几乎没有证据的系统发育信号。此外，在多变量分析中，发育、蚂蚁和化学防御独立变化（正交），似乎彼此独立进化。我们的研究结果是一致的强选择不同的防御性状，可能介导的食草动物。在社区集会的分析中，我们发现，英加物种共同出现的邻居在抗草食动物防御比随机更不同，这表明拥有一个罕见的防御表型增加健身。这些结果表明，与食草动物的相互作用可能是一个重要的轴的生态位分化，允许在一个单一的网站内共存的许多种的印加。植物与食草动物之间的相互作用可能在热带地区显著高的植物多样性的产生和维持中起着关键作用。
Plants and their herbivores constitute more than half of the organisms in tropical forests. Therefore, a better understanding of the evolution of plant defenses against their herbivores may be central for our understanding of tropical biodiversity. Here, we address the evolution of antiherbivore defenses and their possible contribution to coexistence in the Neotropical tree genus Inga (Fabaceae). Inga has > 300 species, has radiated recently, and is frequently one of the most diverse and abundant genera at a given site. For 37 species from Panama and Peru we characterized developmental, ant, and chemical defenses against herbivores. We found extensive variation in defenses, but little evidence of phylogenetic signal. Furthermore, in a multivariate analysis, developmental, ant, and chemical defenses varied independently (were orthogonal) and appear to have evolved independently of each other. Our results are consistent with strong selection for divergent defensive traits, presumably mediated by herbivores. In an analysis of community assembly, we found that Inga species co-occurring as neighbors are more different in antiherbivore defenses than random, suggesting that possessing a rare defense phenotype increases fitness. These results imply that interactions with herbivores may be an important axis of niche differentiation that permits the coexistence of many species of Inga within a single site. Interactions between plants and their herbivores likely play a key role in the generation and maintenance of the conspicuously high plant diversity in the tropics.