Schuettpelz, Eric , Pryer, Kathleen M. , Windham, Michael .
A phylogenetic approach to species delimitation in the fern genus Pentagramma (Pteridaceae).
The goldback and silverback ferns of the American Southwest—composing the genus Pentagramma—are phylogenetically isolated within the xeric-adapted cheilanthoid clade and rather unusual in exhibiting polyploidy without apomixis. These ferns account for a diverse array of morphotypes, cytotypes, and flavonoid chemotypes. However, because the differences among the various entities are generally cryptic, they are usually treated at an infraspecific level. In recent years, as many as five subspecies have been ascribed to P. triangularis and only P. pallida has been considered sufficiently distinct to warrant recognition as a separate (second) species. In this study, we employ nuclear and plastid DNA sequencing to uncover relationships within Pentagramma and test previous hypotheses of species delimitation. We attempt to identify genetically distinct diploid lineages within the genus and characterize the origins of polyploid individuals. Our approach ultimately provides a better understanding of the evolutionary history of this group and an assessment of polyploidy’s role in generating diversity in the absence of apomixis.
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1 - Duke University, Department of Biology, 139 Biological Sciences Building, PO Box 90338, Durham, North Carolina, 27708, USA
low-copy nuclear gene
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Alpine B/Snowbird Center
Date: Monday, July 27th, 2009
Time: 11:00 AM