The Role of Herbivores in the Evolution of Dioecy from Gynodioecy

植物生物学中的一个中心问题是理解雌雄同体何时以及如何进化。最近的研究已经明确指出，环境是促成这一转变的重要因素，然而，很少有人关注环境的敌人层面。本研究的目的是以野生草莓及其修剪花蕾的草食动物为模型系统，评价草食动物在雌雄同体进化中的作用。这项研究将测试一个长期存在的假说，即偏向男性的食草动物如何促进不同性别的进化，以及四个新发展的假说，即草食性如何阻碍这种转变。这些假说将通过温室和实验园艺研究相结合的方式进行验证。食草动物的水平将被操纵，并通过男性和女性的功能来衡量健康状况。这些研究将得到对选择反应的直接测量的补充。这项工作将扩大我们对动植物相互作用的理解，这些相互作用支配着不同性别的进化，包括敌人。在这样做的过程中，它将提供一些关于拮抗剂在育种系统进化中的作用的第一批数据。此外，由于这项研究利用了一种农业物种的野生近亲及其最具破坏性的害虫之一，因此在该系统中收集的抗药性和耐受性数据将与在管理环境中开发杀虫剂使用的替代品相关。

A central problem in plant biology is understanding when and how separate sexes evolve from hermaphroditism. Recent research has pin-pointed the environment as an important element mediating this transition, however, little attention has been paid to the enemy dimension of the environment. The objective of this research is to evaluate the role of herbivory in the evolution of separate sexes from hermaphroditism using the wild strawberry and it's flower bud clipping herbivore as a model system. This research will test a long standing hypothesis for how male-biased herbivory could facilitate the evolution of separate genders as well as four newly developed hypotheses for how herbivory could impede this transition. These hypotheses will be tested using a combination of greenhouse and experimental garden studies. Herbivore levels will be manipulated and fitness through male and female function will be measured. These studies will be complemented by direct measures of the response to selection.This work will expand our understanding of the plant-animal interactions governing the evolution of separate genders to include enemies. In doing so, it will provide some of the first data on the role of antagonists in breeding system evolution. Moreover, because this study utilizes a wild relative of an agricultural species and one of its most damaging pests, data gathered on resistance and tolerance in this system will be relevant to development of alternatives to pesticide use in managed settings.