PANERO, JOSE L.1*, BRUCE G. BALDWIN2, EDWARD E. SCHILLING3, and JENNIFER A. CLEVINGER4. 1Section of Integrative Biology, University of Texas, Austin, TX 78712; 2Jepson Herbarium & Dept. of Integrative Biology, 1001 Valley Life Sciences Bldg. #2465, University of California, Berkeley, CA 94720-2465; 3Department of Botany, University of Tennessee, Knoxville, TN 37996-1100; 4Department of Biology, James Madison University, MSC 7801, Harrisonburg, VA 22807. - Molecular phylogenetic studies of members of tribes Helenieae, Heliantheae, and Eupatorieae (Asteraceae). 1. Introduction.
Past molecular studies aimed at elucidating tribal relationships in
the Asteraceae have revealed a Helenieae-Heliantheae-Eupatorieae (HHE)
clade in a somewhat terminal position in subfamily Asteroideae. This
interesting result and our interest in elucidating further
relationships among these tribes have been the stimulus for the
present study. We believed a comprehensive DNA sequencing effort would
provide a more robust hypothesis of relationships among the genera of
the HHE clade. Sequencing studies have focused on completing data
matrices for 26 primers for several genes, introns and spacer regions
of the chloroplast genome. The final data matrix contains 16,650 bp
for 127 genera of the HHE clade. The regions of the chloroplast genome
sampled include the genes matK, ndhF, ndhD, and accD; the introns of
rpl16, petB, petD, trnL, and 5’trnK-matK, and the spacers between
rpl20-rps12, 23S–16S, accD-rbcL, trnT-trnL, and trnL-trnF.
Phylogenetic studies based on this data matrix reveal the polyphyletic
composition of tribes Helenieae and Heliantheae as currently
circumscribed, with members of tribe Eupatorieae in a highly nested
position within a clade with the Peritylinae and Galeana-Villanova
clade. Moderate to strong jackknife support has been obtained for most
clades in the strict consensus tree.
Key words: Asteraceae, chloroplast DNA, Eupatorieae, Helenieae, Heliantheae, phylogenetics