EAPSI: Evolution and Biogeography of an East Asian-North American Distribution in Sedges, a Hyper-Diverse Group of Flowering Plants

EAPSI：莎草（一种高度多样化的开花植物）东亚-北美分布的进化和生物地理学

• 批准号: 1614294
• 负责人: Jenna Dorey
• 金额: $ 0.54万
• 依托单位: Dorey Jenna
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-06-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1614294&HistoricalAwards=false
• 关键词: EAPSI; Evolution; Biogeography; East; Asian

Sedges (genus: Carex) are one of the five largest genera of flowering plants, and the most diverse plant genus in the temperate zone. Sedges, with an estimated 2100 species, are an ideal group for examining questions about broader patterns of biodiversity and evolution due to 1) high species diversity in the genus, 2) speciation driven by microhabitat specialization, and 3) restricted ability for physical dispersal. Within this genus, a clade of about 60 species in sections Laxiflorae, Paniceae, Limosae, and Bicolores are distributed widely across North America and Eurasia, with two centers of biodiversity in the eastern United States and Japan. The project will utilize a combination of molecular systematics and biogeographic methods to reconstruct the evolutionary relationships of these sedges and model their geographic range shifts through time. The award will allow the researcher to travel to Japan to sample East Asian sedges, including narrowly distributed Japanese endemics. Laboratory work will produce DNA sequences that integrate with data previously generated by the principal investigator for North American sedges. This is a collaborative research project with Dr. Takuji Hoshino, a plant systematist and sedge expert at the Okayama University of Science. During the research in Japan, DNA will be extracted from the collected silica-dried leaf samples. Six DNA sequence regions will be targeted and amplified by PCR. The generated DNA sequences will be edited with Sequencher, then aligned manually and with the program MUSCLE. BEAST, a Bayesian program for phylogenetic analyses, will be used to reconstruct a combined character phylogeny and perform divergence dating by calibrating node ages with fossil data. The research will test the hypothesis that the clade was once widespread throughout a continuous forest in the Northern Hemisphere, and that the present-day patterns of diversity are due to recent species radiations in both eastern North America and Japan. This work will investigate role that Beringia played in shaping patterns of diversity in the present-day flora, and examine long-term range shifts in dispersal-limited flora due to changes in climate and environment. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Japan Society for the Promotion of Science.

莎草属（苔草属）是有花植物的五大属之一，也是温带植物种类最多的属。估计有2100种莎草，是研究生物多样性和进化的更广泛模式的理想群体，因为1)属中物种多样性高，2)由微生境专业化驱动的物种形成，3)物理扩散能力有限。在这个属中，有一个分支，大约有60种，分布在北美和欧亚大陆，在美国东部和日本有两个生物多样性中心。该项目将结合分子系统学和生物地理学方法来重建这些莎草的进化关系，并模拟它们的地理范围随时间的变化。该奖项将允许研究人员前往日本取样东亚莎草，包括分布狭窄的日本特有莎草。实验室工作将产生DNA序列，与之前由首席研究员为北美莎草生成的数据相结合。这是与冈山科学大学植物系统学家和莎草专家Takuji Hoshino博士的合作研究项目。在日本进行研究期间，将从收集的硅干叶片样本中提取DNA。六个DNA序列区域将被定位并通过PCR扩增。生成的DNA序列将用Sequencher编辑，然后用MUSCLE程序手动对齐。BEAST是一个用于系统发育分析的贝叶斯程序，将用于重建组合特征系统发育，并通过使用化石数据校准节点年龄来进行分歧定年。这项研究将验证一个假设，即该分支曾经广泛分布于北半球的一片连续森林中，而今天的多样性模式是由于北美东部和日本最近的物种辐射造成的。这项工作将研究白令陆桥在塑造当今植物群多样性模式中的作用，并研究由于气候和环境变化而导致的分散有限的植物群的长期范围变化。该奖项隶属于东亚和太平洋暑期研究所项目，由美国国家科学基金会和日本科学促进会共同资助，支持一名美国研究生进行暑期研究。