Population Structure and the Evolution of Inbreeding Depression

植物的交配系统具有显著的多样性。 具有混合交配系统的植物物种（例如，两个自我- 受精和异交）提供了一个特殊机会， 研究自然选择如何塑造交配系统 一些 围绕这个问题的争论，因为不同的理论 模型对哪些因素是 重要. 拟议的研究将使用共同的年度， 好望角凤仙花，以检查是否近交衰退 增加或减少与近亲繁殖的历史， 人口 使用电泳，研究人员将分析 近亲繁殖的来源和遗传结构在几个 自然人口。 这些信息将与 近交衰退和遗传负荷 来自竞争实验。 这将揭示， 遗传负荷由于漂移和突变而增加，或者 当近亲繁殖发生时通过选择清除。 这项研究的结果应该有助于确定 可能的遗传效应引导着交配系统的进化。 在 此外，它还应查明下列问题的来源和后果： 自然种群中的近亲繁殖。 这些信息将帮助 阐明了小种群面临的遗传危害， 稀有和受威胁的物种，并可能有助于指导人工 选择和植物育种的农业计划。

Plants display a remarkable diversity of mating systems. Plant species that have mixed mating systems (e.g., both self- fertilize and outcross) provide a special opportunity for studying how natural selection molds the mating system. Some controversy surrounds this issue because different theoretical models make different predictions concerning which factors are important. The proposed research will use the common annual, Impatiens capensis, to examine whether inbreeding depression increases or decreases with a history of inbreeding in a population. Using electrophoresis, the investigator will analyze the sources of inbreeding and genetic structure in several natural populations. This information will be compared to levels of inbreeding depression and genetic load in each population derived from competition experiments. This should reveal whether the genetic load increases due to drift and mutation, or is purged via selection when inbreeding occurs. The results of this research should help determine which possible genetic effects steer mating system evolution. In addition, it should identify the sources and consequences of inbreeding in natural populations. This information will help illuminate the genetic hazards faced by the small populations of rare and threatened species and may help guide artificial selection and plant breeding in agricultural programs.