Systematics Section / ASPT
Ekenäs, Catarina , Andreasen, Katarina , Baldwin, Bruce G. .
Chloroplast DNA evidence on phylogeny of Arnica (Asteraceae-Madieae): comparisons with nuclear ribosomal DNA data.
Chloroplast rpl16, trnT-L, and psbA-trnH spacer sequences were found to contain minimal sequence variation relative to variation in nuclear ribosomal transcribed spacers (ITS and ETS) for 23 Arnica species. The informative chloroplast DNA characters, however, confirm some of the clades in trees resulting from analysis of ITS and ETS variation. A phylogenetic hypothesis based on combined nuclear and chloroplast DNA data indicates that previous circumscriptions of subgenera in Arnica are problematical, although subgenus Austromontana constitutes a monophyletic group if A. dealbata is included and A. latifolia excluded. The molecular phylogenetic results are consistent with a previous hypothesis based on phytochemical studies (flavonoid content) of subgenus Austromontana that proposed that A. cordifolia gave rise to A. discoidea and that A. spathulata descended from A. discoidea. Because of limited chloroplast DNA variation, sequences from additional non-coding regions are needed to achieve a well-resolved chloroplast tree. In addition, sequencing of rapidly evolving, low-copy nuclear regions is being pursued to obtain another line of evolutionary evidence, with the goal of generating a robust phylogeny of Arnica. The phylogeny will later be correlated to secondary metabolite content of the species by obtaining chemical profiles.
1 - University of California, Berkeley, Integrative Biology, University and Jepson Herbaria, 1001 Valley Life Sciences Building, Berkeley, California, 94720-2465, USA
2 - Uppsala University, Systematic Botany, Department of Evolution, Genomics and Systematics, Norbyvägen 18D, Uppsala, SE-752 36, Sweden
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM