Population Structure and the Evolution of Inbreeding Depression

人口结构和近亲繁殖衰退的演变

• 批准号: 8918958
• 负责人: Donald Waller
• 金额: $ 16万
• 依托单位: University of Wisconsin-Madison
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-01-15 至 1993-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8918958&HistoricalAwards=false
• 关键词: Population; Structure; Evolution; Inbreeding; Depression

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.

植物表现出显着的交配系统多样性。 具有混合交配系统（例如，自体受精和异型杂交）的植物物种为研究自然选择如何塑造交配系统提供了特殊的机会。 围绕这个问题存在一些争议，因为不同的理论模型对哪些因素重要做出了不同的预测。 拟议的研究将使用常见的一年生凤仙花（Impatiens capensis）来研究近交衰退是否会随着种群中近交史的增加或减少而增加或减少。 研究人员将利用电泳分析几个自然种群中近亲繁殖的来源和遗传结构。 该信息将与竞争实验得出的每个种群的近交抑制水平和遗传负荷进行比较。 这应该揭示遗传负荷是否由于漂移和突变而增加，或者在近亲繁殖发生时通过选择而被清除。 这项研究的结果应该有助于确定哪些可能的遗传效应引导交配系统的进化。 此外，还应确定自然种群中近亲繁殖的来源和后果。 这些信息将有助于阐明稀有和受威胁物种小种群所面临的遗传危害，并可能有助于指导农业计划中的人工选择和植物育种。