Abstract Detail

Systematics Section

Martinez, Nirzka [1], Santiago, Eugenio [1], Salazar, Jackeline [2], Mateo, Amelia [2].

A preliminary phylogenetic analysis of Caribbean Tabebuia based on nuclear (ITS) and chloroplast (psbD-trnT and rpl32-trnL) molecular regions.

Tabebuia Gomes ex DC. (Bignoniaceae) is an extraordinarily diverse plant genus that comprises species of economical importance. Traditionally, the genus circumscribed ca. 100 Neotropical species (Gentry, 1992), with many (ca. 60 species) confined to the Greater Antilles, especially to the islands of Cuba and Hispaniola. The genus exhibits great morphological variability and adaptations to a great diversity of ecological conditions (dry coastal scrubs, moist subtropical forest, cloud forest, among others). These characteristics make Tabebuia an interesting case to assess plant radiation in the Caribbean islands. Recent molecular studies based on chloroplast data indicate that the genus is paraphyletic (Grose and Olmstead, 2007a), supporting a taxonomic revision that has separated the "traditional Tabebuia" or "Tabebuia sensu lato" into three genera: Handroanthus, Roseodendron and Tabebuia (Grose and Olmstead, 2007b). Still, the relationships between the many species in the Caribbean have not been elucidated. The purpose of the study is to test the monophyly of the Caribbean species of Tabebuia, and to evaluate their evolutionary relationships, diversification, and biogeography. A preliminary phylogeny has been established based on nuclear (ITS) and chloroplast (psbD-trnT, rpl32-trnL) DNA sequences. The position in the phylogeny of members of Crescentieae and the genus Spirotecoma and Ekmanianthe included in the analysis further supports the hypothesis that the "traditional" genus Tabebuia is paraphyletic. Furthermore, the results suggest that the Caribbean group is monophyletic, with a close relationship to predominantly continental species T. rosea and T. aurea. Although additional sampling and molecular analyses are currently underway, the preliminary results clearly show the complexity of the taxa under study. Financial support: University of Puerto Rico (NSF-CREST Program, Biology Department-Rio Piedras campus and UPR Botanical Garden Herbarium); Ministerio de Educación Superior, Ciencia y Tecnología de República Dominicana (MESCyT).

Broader Impacts:

1 - University of Puerto Rico - Rio Piedras, Biology Department, PO Box 23360, San Juan, PR, 00931, USA
2 - Universidad Autónoma de Santo Domingo (UASD), Escuela de Biología, Zona Universitaria, Santo Domingo, DN, República Dominicana

Keywords:
Tabebuia
Handroanthus
Bignoniaceae
Caribbean
ITS
psbD-trnT
rpl32-trnL.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM
Number: PSY031
Abstract ID:535