DISSERTATION RESEARCH: Pollinator-mediated Interspecific Competition in Ipomoea

在许多植物物种中，自交物种从异交祖先反复进化而来。 尽管植物交配系统进化的工作历史悠久，但是，在理解这种进化转变发生的生态背景方面存在重大差距。 有几种假说将自花受精的进化与环境条件联系起来。 其中一个假设认为，当两个物种共存并竞争共享的传粉者时，自花受精可能是有利的，作为减少对这些传粉者的依赖的一种手段，或者作为一种隔离机制，以防止它们之间的基因流动。 本研究的目的是在牵牛花Ipomoea hederacea和I.紫花。从达尔文时代到现在，自花受精和异花受精的意义一直吸引着进化生物学家。拟议的研究将是更好地理解这两种生殖模式之间过渡的一个步骤。 I.常春藤属和I. purpurea将被用来作为一个模型，以检查的作用，自花受精可能发挥生殖隔离机制，并解决更多的机械问题的具体条件下，授粉竞争可能有利于自花受精。

Self-fertilizing species have evolved repeatedly from outcrossing ancestors in a number of plant species. Despite the long history of work on plant mating system evolution, however, there are major gaps in the understanding of the ecological context in which this evolutionary transition occurs. Several hypotheses link the evolution of self-fertilization to environmental conditions. One such hypothesis suggests that self-fertilization can be advantageous when two species co-occur and compete for shared pollinators, as a means of reducing reliance on such pollinators or as an isolating mechanism to prevent gene flow between them. The purpose of the proposed work is to examine this hypothesis in the two morning glory species Ipomoea hederacea and I. purpurea. The significance of self- and cross-fertilization has interested evolutionary biologists from Darwin's time to the present. The proposed research will be a step towards a greater understanding of the transition between these two reproductive modes. The competitive interaction between I. hederacea and I. purpurea will be used as a model to examine the role self-fertilization may play as a reproductive isolating mechanism, and to address more mechanistic questions about the specific conditions under which competition for pollination is likely to favor self-fertilization.