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.

部分可育的藓类种间杂种可以作为研究亲本种间基因流动的模型。苔藓植物（苔藓，地钱和金鱼藻）的生活史，其中二倍体和单倍体代都很发达，提供了一个很好的系统，在其中记录种间杂交的二倍体一代通过遗传分析所产生的重组配子体在单倍体一代。本研究主要针对两种密切相关的泥炭藓（Sphagnummacrophyllum和S. cribrosum）。近缘种间的生殖隔离程度可以通过对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同时出现的整个范围内采集样本。最近发现的一个网站，这两个物种的配子体密切混合提供了一个特殊的机会，测试物种之间的基因流的情况下，它是最有可能发生的。样本中的基因流将使用基因组中变化极大的DNA标记进行评估。数据分析将测试人口遗传学中涉及人口规模和迁移率的最新先进的合并模型。这项研究将提高我们对这一生态和经济上重要的藓类植物群的进化历史的理解。此外，它还将导致更好地了解物种形成所涉及的复杂过程。该奖项为学生研究人员提供了机会，以提高他的博士论文研究，并与他人分享他的发现。