International Research Fellowship Program: Hybridization and Ecological Speciation in the Salt Tolerant Sedges (Carex, Cyperaceae)

国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持Julie A.Dragon博士与加拿大蒙特利尔麦吉尔大学的Marcia Watway博士和英国兰开夏郡Edge Hill大学的Paul Ashton博士合作，为期24个月的研究奖学金。在这项建议中，PI和东道主将测试假说，解决杂交和生态位划分在北大西洋苔草海洋物种形成中的作用。L。(C.Aquatilis，C.Paleacea，C.subspathacea，C.Salina，C.recta，C.haplophila和C.Vacillans)。他们的一般方法是收集与耐盐性相关的形态和生态数据，并将其与物种之间的遗传分化和生态位划分相关联。表型和生态数据将用于确定物种之间的生态位分化，包括中心种群和边缘种群之间的生态位差异，以及不同大陆上同一物种的种群之间的生态位差异。分子数据将被用来改善该群体的系统发育，确定涉及水曲柳S和L种的4个建议的稳定杂种的亲缘关系，推断该物种的生物地理历史，并将遗传多样性与表型和生态多样性联系起来。苔草属(Carex L.)是开花植物中最大的属之一，约有2500种分布于世界各地，几乎存在于所有生境类型中，但在世界湿地中尤为常见。该属的成员是加拿大和欧亚大陆潮湿草甸中的重要类群，在那里它们为许多野生和驯养动物提供饲料、栖息地和水过滤。苔草属植物S代表了一个广泛的和重要的生态分类群，非常适合研究杂交和生态位划分在生态物种形成中的作用。同倍体杂交种为研究这种作用，特别是杂交和生态分化之间的联系提供了很好的模型。PI和寄主将研究S苔草和L苔草之间的分歧范围，查看形态、生态和分子数据，从而使他们有机会具体讨论杂交和生态位分配在这个具有重要生态意义和广泛分布的种群中物种形成中的作用。研究结果将有助于理解植物将如何对全球气候变化下的生态位变化做出反应，特别是在盐沼中，以及类群之间的遗传渗透如何影响物种沿不断变化的环境梯度的分布，为学者和自然保护者提供信息。

0704987DragonThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Julie A. Dragon to work with Dr. Marcia Waterway at McGill University in Montreal, Canada and with Dr. Paul Ashton at Edge Hill University in Lancashire, UK.In this proposal the PI and host will test hypotheses addressing the role of hybridization and niche partitioning in the speciation of the North Atlantic maritime species of Carex aquatilis s. l. (C. aquatilis, C. paleacea, C. subspathacea, C. salina, C. recta, C. haplophila, and C. vacillans) of section Phacocystis (Cyperaceae). Their general approach is to collect morphological and ecological data relevant to salt tolerance and to correlate this to genetic differentiation and niche partitioning among the species. Phenotypic and ecological data will be used to determine niche differentiation among the species, including between central and marginal populations, and between populations of the same species on different continents. Molecular data will be use to improve the phylogeny of the group, to determine the parentage of four suggested stabilized hybrids involving species of C. aquatilis s. l., to infer the biogeographic history of the species, and to correlate genetic diversity with phenotypic and ecological diversity. The genus Carex L. is one of the largest genera of flowering plants, with approximately 2500 species of cosmopolitan distribution, occurring in nearly all habitat types, but particularly common in the wetlands of the world. Members of the genus are important taxa in wet meadows in Canada and Eurasia where they provide fodder for many wild and domesticated animals, habitat, and water filtration. Carex aquatilis s. l. represents a widespread and ecologically important taxon ideally suited for the study of the role of hybridization and niche partitioning in ecological speciation. Homoploid hybrids provide great models for the investigation of this role, specifically the connection between hybridization and ecological divergence. The PI and host will examine the scope of divergence within Carex aquatilis s. l., looking at morphological, ecological, and molecular data, therefore giving them the opportunity to specifically address the role of hybridization and niche partitioning in the speciation in this ecologically significant and widespread group. Outcomes will contribute significantly to the understanding of how plants will respond to niche shifts under global climate change, especially in salt marshes, and how genetic introgression between taxa affects the species distribution along changing environmental gradients, providing information for academics as well as conservationists.