Several bryological research projects are currently taking place at Duke University, with support from the U.S. National Science Foundation.
Linking evolutionary processes and taxonomy in the peatmoss group Sphagnum subg. Cuspidata
DEB1928514. The central aims of this project are to assess species delimitation, phylogenetic relationships, interspecific admixture, and inter- / intra-specific genome structure in Sphagnum, subgenus Cuspidata. Subgenus Cuspidata includes approximately 20-25 species. The project covers a broad range of geographic scales including proximate populations, regional metapopulations, and plants from different continents, and includes three integrated parts. The first aim uses RADSeq to test hypotheses of phylogeographic structure among plants collected in Europe, eastern North America, western North America, Asia, and specifically, whether eastern North American and European plants form a clade sister to plants from western North America and Asia. The RADSeq data will be used to delimit phylogenetic species, including estimates of genetic admixture among species and intraspecific, geographic metapopulation systems. The second aim uses whole genome sequencing to test hypotheses about genomic differentiation among species and geographically disjunct population systems, as well as genomic regions that are shared among species- and population-level clades. A major goal is to assess the physical architecture of shared and differentiated genomic regions across the 19 chromosomes of haploid gametophytes. Comparative analyses will test hypotheses that species differ in genes related to nutrient requirements and water relations, two important niche gradients that differentiate members of Sphagnum subg. Cuspidata. The comparative analyses are facilitated by rich genomic resources available for Sphagnum, including a reference genome and genetic map for a species in subg. Cuspidata (S. fallax). The third and final aim integrates and synthesizes data within a taxonomic revision of the subgenus, including identification keys, descriptions, nomenclatural revisions, illustrations, and distribution maps.
Dimensions: Collaborative Research: Genome structure and adaptive evolution in peatmosses (Sphagnum): ecosystem engineers
DEB1737899. This is a collaborative project between researcher from Duke University, Kenyon College, University of New Mexico, and Oak Ridge National Laboratory.
This research integrates broad-level phylogenetics, common garden experiments of a widely-distributed Sphagnum species, and genus-wide comparative genomic studies to understand how adaptive processes occurring within species scale up to and explain diversification of the genus on a worldwide scale. Whole genome DNA sequences will be assembled for 96 Sphagnum species representing the worldwide range of the genus. These data will then be used to reconstruct phylogenetic relationships among species and assess genus-wide genomic variation. Analyses of these data will then test for correlations among phylogenetic patterns, distributional range, ecological breadth, and variation in ecologically important phenotypic traits. Plants of Sphagnum magellanicum, which occurs from arctic to tropical regions, will be collected across a latitudinal gradient and grown under experimental conditions to assess photosynthetic responses to environmental factors including day length and temperature, and population differentiation in physiological response. Gene expression responses in experimental plants will be measured using RNA sequencing to better understand the genetic basis of local physiological adaptation. Whole genome DNA sequences of different S. magellanicum populations will be assembled to assess variation in gene content within a single species (Pan genome structure). Comparing these population-level data with whole genome sequence data from species spanning the Sphagnum genus will identify how many of these genes are shared with other peatmoss species. One specific prediction these data will be used to test is whether inducible physiological responses in tropical plants of a widespread species have become fixed and constitutive in tropical Sphagnum species.
Digitization TCN: Collaborative Research: Building a global consortium of bryophytes and lichens: keystones of cryptobiotic communities
DBI2001288. Through this collaboration, twenty-five US herbaria, including Duke Bryophyte collection, will image and digitize associated metadata for almost 1.2 million bryophyte and lichen herbarium specimens held in US institutions.
Links: Duke Bryophyte Herbarium, GLOBAL TCN website.
Collaborative Research: AToL: Assembling the Pleurocarp Tree of Life: Resolving the rapid radiation using genomics and transcriptomics
A collaborative project between the University of Connecticut, Chicago Botanical Gardens and Duke University. This study focuses on untangling the relationships among species of pleurocarpous mosses that arose from an explosive diversification, on identifying the geologic or climatic shifts that triggered these events, and on understanding the significance of morphological innovations allowing adaptations to diverse habitats. [–> project website]
A model systematic treatment of a hyper-diverse lineage descended from early land plants (aka, Frullania project)
A collaborative project between the Field Museum Chicago & Duke University, preparing monograph of two lineages within liverwort genus Frullania. [–> Frullania portal]
Phylogeny and speciation in Sphagnum section Subsecunda
The project has three major components. The first part involves a global analysis of peatmoss diversity in order to determine if genetic relationships reflect geographic proximity, or structural similarity among plants; that is, have similar morphologies in widely disjunct regions evolved convergently?. The second part of the research investigates ecological, genetic, and morphological variation in a group of closely related species surrounding S. subsecundum s.s. that are widespread in North America, Europe, and Asia.
NSF-PEET (Partnerships for Enhancing Expertise in Taxonomy): Systematics of the Daltoniaceae
(Collaborative with W. R. Buck, New York Botanical Garden)
NSF-ATOL (Assembling the Tree of Life): Phylogeny of liverworts
The project is a comprehensive collaborative investigation of liverwort phylogeny. The research team includes B. Goffinet (University of Connecticut: chloroplast genomics), Y. Qiu (University of Michigan: mitochondrial genomics), K. Renzaglia (Southern Illinois University: ultrastructural morphology), B. Crandall Stotler & R. Stotler (Southern Illinois University: anatomy, morphology, taxonomy), J. Engel & M. von Konrat (Field Museum in Chicago, specimen vouchering, taxonomy, educational outreach), N. Celinese & R. Beaman (Yale University: informatics), J. Shaw (Duke University: nucleotide sequencing).
Moss Diversity Project
Population genetics in Ceratodon purpureus
Databasing Southeastern Bryophytes
Fungal Endophytes in Bryophytes
Checklist of the Mosses of North Carolina
(link to the current site)