Systematics Section / ASPT
Topalov, Katarina , Mort, Mark E. , Neeff, Philipp , Lakusic, Dmitar , Zlatkovic, Bojan .
Preliminary phylogenetic analyses of Sempervivum (Crassulaceae) inferred from DNA sequence data.
SEMPERVIVUM (Crassulaceae) is a medium size genus comprising 50 species of hardy alpine leaf-succulents. The genus is distributed mainly in mountainous regions of central and southern Europe and the Mediterranean. Phylogenetic studies of Crassulaceae confirm that Sempervivum is monophyletic and place the small genus Jovibarba (five taxa) as sister to the genus; however, other studies have suggested that Jovibarba is actually derived within Sempervivum. Although the phylogenetic position of Jovibarba relative to Sempervivum is still debated, the genus was separated from Sempervivum based primarily on the differences in flower morphology; Jovibarba species have 6-parted, bell-shaped flowers, whereas species of Sempervivum have polymerous flowers. This difference in floral morphology is striking; however within other genera of Crassulaceae, similar shifts in floral morphology have been shown to be a derived (multiple times) within larger genera. There has not yet been a focused phylogenetic study of Sempervivum. We used parsimony analyses of DNA sequence data derived from the nuclear ITS regions (including 5.8S) and four putatively rapidly evolving cpDNA regions: rpoB-trnC, rps16, rpl16 and psbM-trnD to reconstruct phylogeny for Sempervivum. Our analyses indicate that these data will provide a robust estimate of phylogeny for Sempervivum. Our preliminary analyses provide strong support for a monophyletic Jovibarba that is sister to the Sempervivum clade. This result coupled with the aforementioned floral morphological differences suggest that Jovibarba is a morphologically and phylogenetically divergent taxon that warrants taxonomic recognition. Furthermore, our data suggest that several widespread species of Sempervivum are not monophyletic, suggesting a need for a taxonomic revision of the genus.
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1 - University of Kansas, Department of Ecology & Evolutionary Biology, Natural History Museum and Biodiversity Research Center, 1200 Sunnyside Avenue, Lawrence, Kansas, 66045-7534, USA
2 - 1969 Loring Ave., San Diego, California, 92109-1406
3 - Burgunderstr. 29, Wuppertal, 42285, Germany
4 - University of Belgrade, Biology, Botanical Institute and Garden, Takovska 43, Belgrade, 11000, Serbia and Montenegro
5 - University of Nis, Faculty of Sciences and Mathematics, Visegradska 33, PO Box 224, Serbia, 18000, Nis
Presentation Type: Poster:Posters for Sections
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM