Systematics Section / ASPT
Neves, Susana S. , Hoot, Sara B. .
Evolution and systematics of Menispermaceae based on plastid DNA sequences.
Menispermaceae ("moonseed family") comprises more than 70 genera and 500 species of dioecious lianas or climbing shrubs (rarely erect shrubs or herbs) distributed worldwide, mainly in tropical lowlands. Intrafamilial relationships have been difficult to ascertain and available classifications disagree as to the number and composition of major groups. In this study, atpB and rbcL plastid genes were sequenced to produce a family phylogeny. Sampling included >40 genera, representing all tribes and subtribes recognized in earlier classifications. A multiple outgroup was selected based on previous molecular studies in the Ranunculales. In all analyses, including maximum parsimony (MP) and Bayesian, Menispermaceae is a highly supported monophyletic group (MP bootstrap 100%; PP 1.0). Relationships among the earliest diverging lineages in the family remain uncertain, but several well-supported clades are found. Results clearly indicate that Cissampelos, Cyclea and Antizoma (subtribe Cissampelinea Diels) form a strongly supported monophyletic group, closely related to Stephania. Another well-supported group is a redefined tribe Anamirteae Diels, including Anamirta, Arcangelisia, Coscinium and Tinomiscium (Diels placed Tinomiscium in tribe Fibraureae), but a morphological synapomorphy for Anamirteae (essentially Indo-Malesian) has not been found. The neotropical tribe Anomospermeae Miers (extended to include more recently described genera) may be monophyletic, but sampling in the group is limited. Another geographically restricted and well-supported clade consists of Burasaia and Spirospermum, genera endemic to Madagascar. Results also suggest that some fruit characters traditionally used to delimit groups, such as lack of endosperm (tribe Pachygoneae Miers), are homoplastic and thus misleading. Evolution of other morphological characters in the family will be briefly discussed.
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1 - University of Wisconsin-Milwaukee, Department of Biological Sciences, P.O. Box 413, Milwaukee, Wisconsin, 53201, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Boulevard C/Hilton
Date: Wednesday, July 11th, 2007
Time: 11:00 AM