DISSERTATION RESEARCH: Speciation and hybridization in the moss genus Sphagnum

论文研究：苔藓属的物种形成和杂交

• 批准号: 0710178
• 负责人: Arthur Shaw
• 金额: --
• 依托单位: Duke University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-07-01 至 2010-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0710178&HistoricalAwards=false
• 关键词: DISSERTATION; RESEARCH; Speciation; hybridization; moss

Partially fertile, interspecific hybrids of mosses can serve as a model for studying gene flow between parent species. The bryophyte (moss, liverworts and hornworts) life cycle, in which both diploid and haploid generations are well developed, provides an excellent system in which to document interspecific hybridization in the diploid generation through genetic analysis of the resulting recombinant gametophytes in the haploid generation. This investigation of gene flow will focus on two closely related species of Sphagnum moss (Sphagnum macrophyllum and S. cribrosum). The amount of reproductive isolation between closely related species can be determined through genetic analyses of the recombinant gametophytes produced by their partially fertile, interspecific hybrids. Samples will be collected throughout their ranges where the two species occur together and where they do not. The recent discovery of a site where gametophytes of both species are intimately intermixed provides an exceptional opportunity to test for gene flow between species under circumstances where it is most likely to occur. Gene flow in the samples will be evaluated using DNA markers in extremely variable stretches of the genome. Data analyses will test newly advanced coalescence models in population genetics that involve population size and migration rates. This study will improve our understanding of the evolutionary history of this ecologically and economically important group of mosses. In addition, it will also lead to a better understanding of the complex processes involved in speciation. This award provides the student investigator opportunities to enhance his doctoral dissertation study and share his discoveries with others.

苔藓的部分可育、种间杂交可以作为研究亲本物种之间基因流动的模型。苔藓植物（苔藓、地钱和金鱼草）的生命周期中，二倍体和单倍体世代都发育良好，提供了一个优秀的系统，通过对单倍体世代中所得的重组配子体进行遗传分析，记录二倍体世代中的种间杂交。这项基因流研究将重点关注两种密切相关的泥炭藓物种（Sphagnum macrophyllum 和 S. cribrosum）。密切相关的物种之间的生殖隔离程度可以通过对其部分可育的种间杂种产生的重组配子体进行遗传分析来确定。将在两个物种同时出现和不出现的整个范围内收集样本。最近发现两个物种的配子体紧密混合的地点，为在最有可能发生的情况下测试物种之间的基因流动提供了绝佳的机会。样本中的基因流将使用极其可变的基因组片段中的 DNA 标记进行评估。数据分析将测试涉及种群规模和迁移率的种群遗传学中​​最新先进的合并模型。这项研究将增进我们对这一具有生态和经济重要性的苔藓类群进化历史的理解。此外，它还将有助于更好地理解物种形成所涉及的复杂过程。该奖项为学生研究者提供了加强博士论文研究并与他人分享发现的机会。