Systematics Section / ASPT
Rai, Hardeep , Graham, Sean W. .
Deep phylogenetic relationships of leptosporangiate ferns.
LEPTOSPORANGIATE ferns are a large clade of ~33 families, second only to angiosperms in total diversity within the vascular plants. To date, most phylogenetic studies of pteridophyte (and leptosporangiate fern) relationships have a relatively limited sampling of loci. Recent studies have provided strong support for the backbone of pteridophyte relationships, but relationships within this clade are only partially resolved or supported in several critical areas. Using a large DNA data set sampled from across the plastid genome (~14 kb per exemplar taxon), we attempt to make a well-supported inference of the major branches of leptosporangiate fern phylogeny. We report on an expanded sampling of families, including six families not included in our previous analyses. We observe strong bootstrap support and bayesian posterior-probabilities across almost all of our plastid-based phylogeny. We also discuss issues that may cause potential mis-inference of higher-order relationship, such as the substantial rate heterogeneity we observe across lineages. Analyses that explore different partitions of the data produce generally compatible trees, which are also largely congruent with other recent molecular studies. However, we also find some conflicts concerning the exact branching order within key lineages, including the placement of the “basal” leptosporangiate fern families Gleicheniaceae and Hymenophyllaceae.
Log in to add this item to your schedule
1 - University of British Columbia, Botanical Garden And Centre For Plant Research, 6804 Sw Marine Drive, Vancouver, British Columbia, V6T 1Z4, Canada
Presentation Type: Oral Paper:Papers for Sections
Location: 144/Performing Arts Center
Date: Tuesday, August 1st, 2006
Time: 8:15 AM