Systematics Section / ASPT
Volz, Stefanie , Kocyan, Alexander , Renner, Susanne S. .
Assessment of the value of ITS and trnL for a study of sexual system evolution in Bryonia and Ecballium(Cucurbitaceae).
Based on a multi-locus family-wide phylogeny of Cucurbitaceae (Kocyan et al., this meeting), Bryonia and Ecballium form an isolated clade near the base of Cucurbitoideae, the larger of the two subfamilies of cucurbits. Traditionally, both genera were placed in Benincaseae, but that tribe is highly polyphyletic. Bryonia consists of perhaps 12 species and Ecballium of one, but species and subspecies circumscriptions in both genera are problematic (Jeffrey, 1969). Both are distributed in the Mediterranean, Irano-Turranian, and (in part) Holarctic floral kingdoms and both have received attention from geneticists and ecologists because of their labile sexual systems, with species under certain conditions monoecious, under others dioecious. For a phylogeographic study of sexual system evolution in Bryonia, we are cloning and sequencing nuclear ITS and the plastid trnL intron and spacer. The entities analyzed so far span the diversity of Bryonia, including three accessions of B. alba from Bavaria, one of B. cretica from Greece, three of B. dioica from Western Germany, one of B. marmorata from Sardinia, and one of B. verrucosa from Gran Canaria. For ITS, we found up to seven paralogous copies per accession. For trnL, we found impressive interspecific differences, but little intraspecific variation. Dense sampling of populations throughout Europe is planned for this summer, with a goal of relating the distribution of the two sexual systems to local conditions and historic range changes of Bryonia and Ecballium. Man is expected to have modified ranges because of the medicinal use of some forms of Bryonia against lung ailments.
Cucurbitaceae phylogenetic tree
1 - Ludwig-Maximilians Universitaet Muenchen, Faculty of Biology, Munich, D-80638
Presentation Type: Poster
Location: Special Event Center (Cliff Lodge)
Date: Tuesday, August 3rd, 2004
Time: 12:30 PM