Systematics Section / ASPT
Schultz, Allison , Simmons, Mark P. .
Phylogeny of the Celastreae (Celastraceae): toward placing khat within a natural classification.
CELASTRACEAE tribe Celastreae, as defined by Loesener (1942) in the most recent comprehensive classification of the family, includes about 350 species of trees and shrubs in 15 genera that are native to tropical and subtropical regions. Recent morphological and molecular phylogenetic analyses have shown that the subfamilies and tribes delimited by Loesener are artificial. Despite the many genera sampled in these studies, resolution and support for many of the branches provided an insufficient basis from which to propose a new classification. This problem is being addressed by increased taxon and character sampling. In this study at least two species of each genus within the Celastreae are being sampled, in addition to genera hypothesized to be closely related to members of the tribe. Molecular sampling will consist of two plastid loci, matK and trnL-F, and two nuclear loci, ITS rDNA and the 5’end of 26S rDNA. Morphological characters sampled will include variation in gross morphology, seed anatomy and development, leaf and wood anatomy, pollen morphology, and karyotype. The Celastreae genera Catha and Maytenus are of particular interest. Grown for its stimulant properties, khat (Catha edulis) is a major economical and cultural component in several countries of East Africa and the Arabian Peninsula. Determination of its closely related genera will provide candidates for species containing cathinone-related compounds that will be useful to infer the evolution of cathinone’s biosynthetic pathway. The genus Maytenus has been resolved as polyphyletic in previous analyses. The current study will be used as a basis from which to delimit Maytenus sensu stricto as well as potential segregate genera.
Log in to add this item to your schedule
Program in Molecular Plant Biology at Colorado State University
1 - Colorado State University, Department of Biology, Fort Collins, Colorado, 80523-1878, USA
Presentation Type: Array
Location: Auditorium/Bell Memorial Union
Date: Tuesday, August 1st, 2006
Time: 12:30 PM