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

Dragon Julie A, Underhill VT

Investigators

Abstract

0704987 Dragon The 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.