Systematics/Phytogeography / Taxonomie/ Section
Porter-Utley, Kristen E. , Krosnick, Shawn , McDade, Lucinda .
Untangling the passionflower vines: preliminary insights on the phylogeny of Passiflora subg. Decaloba based upon ncpGS sequences.
Passiflora is a large genus of ca. 550 species of vines, lianas, and trees known for its incredible morphological diversity and stunningly beautiful flowers. The genus is currently recognized with five subgenera: Astrophea, Decaloba, Deidamioides, Passiflora, and Tetrapathea. The largest and most diverse subgenera are Passiflora and Decaloba, each consisting of ca. 235 species. Due to its economic significance, subg. Passiflora has been the focus of most recent scientific study. The equally fascinating and species-rich subg. Decaloba has been largely ignored, yet this group displays equivalent morphological and ecological variation. Moreover, it consists of many species that are currently recognized as threatened or endangered and has special biogeographic significance in that it is the only clade in the genus with species naturally present in both the New and Old World. Subgenus Decaloba contains eight supersections, of which only two, Disemma and Cieca, have been tested for monophyly. Thus, we present here a preliminary phylogenetic analysis of subg. Decaloba based on ncpGS (chloroplast-expressed glutamine synthetase) data and including taxa that represent all supersections in subgenus Decaloba. These data support the monophyly of supersections Disemma, Cieca, Bryonioides and Pterosperma, but suggest that Multiflora, Auriculata, Hahniopathanthus, and Decaloba are likely paraphyletic as currently defined. Morphological and molecular synapomorphies for the monophyletic lineages are provided. We also use the ncpGS dataset to explore rates of diversification across the subgenus. Recent analyses with limited sample sizes have suggested that rates of nucleotide substitution have been relatively constant across Decaloba. Given the morphological variability observed in this clade, these conclusions are revisited and possible explanations for this diversity are considered. This is the first presentation stemming from NSF 0717084 to PIs P. JĂ¸rgensen, S. Krosnick, L. MacDougal, L. McDade, and K. Porter-Utley.
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Passiflora Research Network
1 - Keene State College, Biology, 229 Main Street, MS-2001, Keene, NH, 03435, USA
2 - Rancho Santa Ana Botanic Garden, Research, 1500 North College Avenue, Claremont, CA, 91711, USA
3 - Rancho Santa Ana Botanic Garden, 1500 North College Avenue, Claremont, California, 91711, USA
Presentation Type: Oral Paper:Papers for Sections
Date: Wednesday, July 30th, 2008
Time: 1:15 PM