Abstract Detail

Systematics Section / ASPT

Simoes, Andre [1], Endress, Mary [1], van der Niet, Timo [1], Kinoshita, Luiza [2], Conti, Elena [1].

Tribal and intergeneric relationships in Mesechiteae (Apocynaceae, Apocynoideae): evidence from three non-coding plastid DNA regions and morphology.

The Neotropical tribe Mesechiteae (Apocynaceae) is currently considered to include nine genera: Allomarkgrafia, Galactophora, Macrosiphonia, Mandevilla, Mesechites, Quiotania, Secondatia, Telosiphonia and Tintinnabularia. Tribal and intergeneric relationships, however, are in dispute. To test the monophyly of the tribe and evaluate intratribal relationships, a maximum parsimony analysis was conducted based on DNA sequences from the plastid rpl16 intron, rps16 intron and trnS-G intergenic spacer region as well as morphological data for 23 taxa of Mesechiteae and 11 taxa from other tribes of Apocynoideae. Mesechiteae, as currently circumscribed, is found to be polyphyletic. Only removal of Secondatia and Galactophora and inclusion of Forsteronia renders the tribe monophyletic. Thus defined, Mesechiteae forms a strongly supported clade including seven genera in three subclades : the Mesechites subclade (comprising Tintinnabularia, Allomarkgrafia and Mesechites), the Forsteronia subclade (containing only Forsteronia) and the Mandevilla subclade (comprising Macrosiphonia, Mandevilla and Telosiphonia). Allomarkgrafia is nested in Mesechites. Macrosiphonia and Telosiphonia form two distinct monophyletic clades. Both, however, are nested in Mandevilla. Results suggest upholding the following genera in Mesechiteae: Allomarkgrafia, Forsteronia, Mandevilla, Mesechites and Tintinnabularia. The status of Quiotania could not be evaluated.

1 - University of Zürich, Institute of Systematic Botany, Zollikerstrasse 107, Zurich, Zurich, CH-8008, Switzerland
2 - Universidade Estadual de Campinas, Departamento de Botanica, Caixa Postal 6109, Campinas, Sao Paulo, 13083 970, Brazil

Keywords:
Apocynaceae
Mesechiteae
phylogenetic systematics
morphology
rpl16 intron
rps16 intron
trnS-G intergenic spacer.

Presentation Type: Paper
Session: 18-5
Location: Cottonwood A (Snowbird Center)
Date: Monday, August 2nd, 2004
Time: 2:15 PM
Abstract ID:171