Dissertation Research: Competition and Genotypic Diversity in Poeciliopsis

论文研究：拟青藻的竞争和基因型多样性

• 批准号: 8815423
• 负责人: Robert Vrijenhoek
• 金额: $ 0.57万
• 依托单位: Rutgers University New Brunswick
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-01-15 至 1991-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8815423&HistoricalAwards=false
• 关键词: Dissertation; Research; Competition; Genotypic; Diversity

In the fish genus Poeciliopsis (Poeciliidae) all female clones coexist in Mexican desert streams with males and females of closely related sexually reproducing species. Past work has confirmed that genetically fixed differences in the use of food resources and habitat space contribute to the coexistence of sexual and asexual lines. The proposed study consists of two parts. (1) Competition experiments within and between two clonal lines and a sexual line will be conducted in artificial streams to test whether genetically variable populations show lowered intraspecific competition relative to monoclonal populations. Results from this study will shed light on the ecological advantage of sexual reproduction. (2) Field studies will quantify natural densities and relative frequencies of the two clonal lines and the sexual line. Results from these collections will show the relative reproductive success of the above three lines in a range of densities and relative frequencies. Such ecological studies are necessary for increasing knowledge of the costs and benefits of genetic variability in natural populations. However, this study also has potential applied value as well. Genetically uniform populations can grow well in controlled environments, such as well fertilized and well watered agricultural fields, but are unlikely to perform as well in uncontrolled environments. Both aquaculturists and conservationists are confronted with maintaining populations in uncontrolled environments, and therefore need to understand the ecological benefits of maintaining genetic variation in these populations.

在鱼属Poeciliopsis(Poeciliidae)中，所有雌性克隆与近亲有性生殖物种的雄性和雌性共存于墨西哥沙漠溪流中。过去的研究已经证实，在食物资源和栖息地空间的使用上，遗传固定的差异有助于有性和无性品系的共存。这项拟议的研究包括两个部分。(1)两个无性系和有性系之间的竞争实验将在人工溪流中进行，以测试遗传变量群体是否表现出相对于克隆群体的种内竞争降低。这项研究的结果将揭示有性繁殖的生态优势。(2)田间研究将量化两个无性系和有性系的自然密度和相对频率。这些收集的结果将显示上述三个品系在一定密度和相对频率范围内的相对繁殖成功。这样的生态学研究对于增加对自然种群中遗传变异的成本和收益的了解是必要的。然而，本研究也具有潜在的应用价值。基因一致的种群可以在受控环境中很好地生长，例如肥沃和灌溉良好的农田，但在不受控制的环境中不太可能表现得那么好。水产养殖者和自然资源保护者都面临着在不受控制的环境中维持种群的问题，因此需要了解在这些种群中保持遗传变异的生态效益。