Abstract Detail

Pteridology

Patel, Nikisha [1], Fawcett, Susan [2], Sundue, Michael A. [3], Budke, Jessica [4].

A Phylogenetic Perspective on Perispore Morphology of Thelypteridaceae.

The importance of fern spore perine morphology is little understood. Previous studies suggest that character states pertaining to the often elaborate ornamentation of spores may be synapomorphic for some clades. However, for many groups of ferns the relative utility of various characters and the taxonomic scale at which they may be informative are not known. The Thelypteridaceae is among the largest fern families, and one for which generic circumscription is still contentious. In the present study, we generate sequence data for 16 species, and employ the software SUMAC to construct a supermatrix of published and unpublished data, thereby expanding phylogenetic representation for the Thelypteridaceae to 214 species. We generated SEM images of spores from 46 species and coded perine morphology as seven discrete characters. Augmenting our results with previously published SEM images representing 66 species, we optimized character states onto a phylogeny comprising 214 species, equivalent to 10% of species diversity in the family. Perine character optimization revealed synapomorphies for several genera, including Amauropelta, Stegnogramma, and Goniopteris. Likelihood-based assessment of phylogenetic signal for seven discrete characters associated with spore morphology reveals those which are useful at broad or fine phylogenetic scales. Characters representing macrostructure shape are phylogenetically informative on the generic level, whereas macrostructure reticulation is often synapomorphic for subgeneric clades and sections. We suggest that spore morphology is worthy of further exploration as a source of morphological characters with phylogenetic utility.

1 - University of Tennessee, Ecology and Evolutionary Biology, Knoxville, TN, 37996, USA
2 - University Of Vermont, 111 Jeffords Hall 63 Carrigan Drive, Burlington, VT, 05405, United States
3 - University of Vermont, The Pringle Herbarium, Department of Plant Biology, Burlington, VT, 05405, USA
4 - Univeristy of Tennessee, Hesler Hall, 1406 circle drive, Knoxville, TN, 37996

Keywords:
Pteridophytes
Systematics
Phylogenetics
Spores
ferns.

Presentation Type: Oral Paper
Session: 5, Pteridology I
Location: 108/Mayo Civic Center
Date: Monday, July 23rd, 2018
Time: 10:30 AM
Number: 5010
Abstract ID:747
Candidate for Awards:None