Abstract Detail

Systematics Section / ASPT

Goodson, Barbara [2], Jansen, Robert K. [2], Santos-Guerra, Arnoldo [1].

Molecular systematics of Descurainia (Brassicaceae) in the Canary Islands: biogeographic and taxonomic implications.

The genus Descurainia (Brassicaceae) comprises approximately 45 species distributed throughout temperate areas of the Old and New World. Most species are located in the New World and are disjunctly distributed between North America and western South America. Of the nine Old World species, seven are endemic to the Canary Islands, where they occupy different ecological zones on the islands of Gran Canaria, La Gomera, La Palma, and Tenerife. In contrast to the herbaceous annuals and biennials in the rest of the genus, the Canarian species are self-incompatible woody perennials. A molecular-based phylogeny of Canarian Descurainia has been constructed using DNA sequences obtained for nuclear ITS, chloroplast rps16 and trnL introns, and chloroplast trnD-trnE, trnE-trnT, trnL-trnF, ycf9-trnFM, and ndhF-rpl32 intergenic spacer regions. The Canary Island species and the European monotypic genus Hugueninia form a monophyletic group which is nested within Descurainia. The molecular data suggests a single introduction onto Tenerife with subsequent radiation into different habitats and several dispersals to other islands.

1 - Jardin de Aclimatacion de la Orotava, Calle Retama Numero 2, Puerto de la Cruz, Teneri, Canary Islands, E-38040, Spain
2 - University of Texas at Austin, Section of Integrative Biology, 1 Universiy Station, #A6700, Austin, Texas, 78712, USA

Keywords:
biogeography
Brassicaceae
Islands
Macaronesia
Descurainia.

Presentation Type: Paper
Session: 43-5
Location: Cottonwood A (Snowbird Center)
Date: Wednesday, August 4th, 2004
Time: 9:00 AM
Abstract ID:631