| Abstract Detail
From Gels to Genomics: The Evolving Landscape of Pteridology. A Celebration of Gerald Gastony's Contributions to Fern Evolutionary Biology Windham, Michael [1], Beck, James [1], Grusz, Amanda L. [1], Huiet, Layne [1], Rothfels, Carl [1], Schuettpelz, Eric [1], Yatskievych, George [2], Pryer, Kathleen M. [1]. Using plastid and nuclear DNA sequences to redraw generic boundaries and demystify species complexes in cheilanthoid ferns. Having spent a significant portion of their careers studying cheilanthoids, Rolla and Alice Tryon still considered them to be “the most contentious group of ferns with respect to a practical and natural generic classification.” This troublesome reputation of cheilanthoids, a large (400–500 species) clade within the family Pteridaceae, is well deserved. These ferns exhibit extensive morphological convergence (driven by adaptation to xeric habitats), as well as rampant hybridization, polyploidy and apomixis. The result is a classification in which monophyly has turned out to be an exception rather than the rule. In an effort to better understand cheilanthoid relationships and arrive at a more natural classification, we have initiated a large scale phylogenetic study of these ferns using DNA sequences derived from three plastid regions (rbcL, atpA, trnG-R) and a newly developed nuclear marker (gapCp). Building on earlier molecular work by Jerry Gastony and others, our multi-gene plastid tree now includes nearly one third of all cheilanthoid species. Phylogenetic analyses of these data have allowed us to identify a number of monophyletic subclades, which can be recognized as genera. Using the rapidly evolving nuclear gapCp locus, we have also been able to clarify relationships in several of the most difficult species groups. Our results indicate that these loci, used in combination with other types of data (e.g., morphology, cytogenetics, and isozymes), can go a long way in helping us to understand evolutionary history within this contentious group of ferns.
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1 - Duke University, Department of Biology, Durham, NC, 27708, USA
2 - Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri, 63166, USA
Keywords:
apomixis
gapCp
hybridization
molecular systematics
polyploidy
Pteridaceae.
Presentation Type: Symposium or Colloquium Presentation
Session: S6
Location: Room 5/Woodward
Date: Tuesday, July 29th, 2008
Time: 9:15 AM
Number: S6003
Abstract ID:686 |
