A Diploids-First Approach to Species Delimitation and Interpreting Polyploid Evolution in the Fern Genus Astrolepis (Pteridaceae)

Journal Article (Journal Article)

Polyploidy presents a challenge to those wishing to delimit the species within a group and reconstruct the phylogenetic relationships among these taxa. A clear understanding of the tree-like relationships among the diploid species can provide a framework upon which to reconstruct the reticulate events that gave rise to the polyploid lineages. In this study we apply this “diploids-first” strategy to the fern genus Astrolepis (Pteridaceae). Diploids are identified using the number of spores per sporangium and spore size. Analyses of plastid and low-copy nuclear sequence data provide well-supported estimates of phylogenetic relationships, including strong evidence for two morphologically distinctive diploid lineages not recognized in recent treatments. One of these corresponds to the type of Notholaena deltoidea, a species that has not been recognized in any modern treatment of Astrolepis. This species is resurrected here as the new combination Astrolepis deltoidea . The second novel lineage is that of a diploid initially hypothesized to exist by molecular and morphological characteristics of several established Astrolepis allopolyploids. This previously missing diploid species is described here as Astrolepis obscura.

Full Text

Duke Authors

Cited Authors

  • Beck, JAMESB; Windham, MICHAELD; Yatskievych, GEORGE; Pryer, KATHLEENM

Published Date

  • April 2010

Published In

Volume / Issue

  • 35 / 2

Start / End Page

  • 223 - 234

Electronic International Standard Serial Number (EISSN)

  • 1548-2324

International Standard Serial Number (ISSN)

  • 0363-6445

Digital Object Identifier (DOI)

  • 10.1600/036364410791638388


  • eng