A Preliminary Phylogeny of Caribbean Tabebuia Based on the Nrdna ITS Region

A preliminary phylogeny of Caribbean Tabebuia based on the nrDNA ITS region

T. berterii T. acrophylla T. schumanniana T. ophiolitica T. densifolia

T. rosea T. heterophylla T. ricardii T. acrophylla T. ricardii T. polyantha

Introduction Preliminary Results

Tabebuia Gomes ex DC. (Bignoniaceae) is an extremely diverse Overview Neotropical genus of woody species with great economical value and wide distribution from Mexico to Argentina. Although ca 108 taxa have been The preliminary reconstructed phylogeny (Figure 2) suggests that the genus described (Gentry, 1992), approximately 61 are distributed throughout the Tabebuia is paraphyletic, congruent with chloroplast DNA sequence data Caribbean with 88% endemicity to the region (Figure 1). The genus also (Grose and Olmstead, 2007). In addition, the data shown suggest a clade exhibits great versatility in morphological variation (e.g., flower color, uni- that consist of 3 continental species (T. ochracea, T. guayacan, and T. foliolate to multi-foliolate), as well as adaptations to a wide range of impetiginosa). Another clade contains the sampled Caribbean taxa in close ecological conditions (e.g., from cloud forest to arid zones, diverse geology, relationship with a pair of continental taxa (T. rosea and T. aurea). and high to low altitudes). However, the evolutionary relationships of the Caribbean species has still not been elucidated. The purpose of the study is Cuba/Bahamas-Hispaniola relationship to test the monophyly of the Caribbean group and evaluate the evolutionary The two species sampled that occur in Cuba and the Bahamas (T. relationships. In addition, the gathered information will help evaluate bahamensis and T. lepidota) are related to the sampled Hispaniolan taxa, patterns of morphological evolution, adaptive-ecological diversification, as with the exception of T. ophiolitica. However, Cuba/Bahamas-Hispaniola well as biogeographical patterns. grouping has a low bootstrap support.

Methods Puerto Rico and eastern Caribbean taxa There is no robustness for grouping Puerto Rican species with the The preliminary analysis includes 19 species from Taxonomic sampling. exception of the two endemic species that are distributed in the cloud forest the genus Tabebuia and outgroups representing different genera in the ecological life zone (T. rigida and T. schumanniana). They differ by only one Bignoniaceae family. base pair position on the analyzed sequences. T. heterophylla, considered to be a highly diverse and widely distributed species throughout the Genomic DNA was DNA extraction, amplification, and sequencing. Caribbean, including Puerto Rico, seems to have a close relationship with T. extracted from leaves using Dneasy Plant Mini Kit (Qiagen). PCR was used pallida, a species considered to be distributed in the eastern Caribbean and to amplified the nrITS region using the set of primers ITS-5ang, specific for often confused with T. heterophylla. angiosperm plants, and universal primer ITS-4. PCR products were cleaned and sequenced. Sequencher 4.9 (Gene Codes) was used for contig Caribbean group relationship with continental T. rosea and T. aurea assembly and sequence editing. Two continental species come out in the Caribbean clade. T. rosea is Phylogenetic analysis. MEGA 4.0 (Tamura, Dudley, Nei, and Kumar, 2007) imbedded in the clade (bootstrap support 100%). Although T. aurea also was used for the ClustalW multiple sequence alignment feature and comes out as related to the Caribbean group, bootstrap support is weak. phylogenetic analysis. The evolutionary history was inferred under These patterns for T. aurea and T. rosea with the Caribbean taxa coincide Maximum Parsimony optimality criterion. The resulting bootstrap consensus with results from chloroplast sequence data (Grose and Olmstead, 2007). tree inferred from 1000 replicates is taken to represent the evolutionary history of the taxa analyzed. Branches corresponding to partitions Future Directions reproduced in less than 50% bootstrap replicates were collapsed. • To continue the taxonomic sampling of the genus in additional

Taxa Distribution geographical regions.

Bahamas/Cuba • Incorporate other nuclear and chloroplast regions to add resolution to Dominican Republic elucidate the evolutionary relationships. Puerto Rico

Widespread and/or Eastern Caribbean • Carry out ecological and morphological (e.g., leaves and flower)

Continental assessments of the taxa.

Figure 1. Distribution of Tabebuia in Literature Cited the Greater Antilles and the Bahamas (number of Gentry, A.H. 1992. Bignoniaceae – Part II (Tribe Tecomeae). Flora species/number of endemic species). Neotropica Monograph 25. New York: New York Botanical Garden

Grose, S.O. and R.G. Olmstead. 2007. Evolution of a charismatic Neotropical Clade: Molecular Phylogeny of Tabebuia s. l., Crescentieae, and Allied Genera (Bignoniaceae). Systematic Botany 32: 650-659. Figure 2. Maximum Parsimony consensus tree. Branches with bootstrap Tamura, K., J. Dudley, M. Nei, and S. Kumar. 2007. MEGA4: Molecular support greater than 50% are shown above the branches. Branches with less Evolutionary Genetics Analysis (MEGA) software version 4.0. Molecular than 50% are collapsed in a polytomy. Biology and Evolution 24:1596-1599.

T. obovata T. heterophylla T. obovata T. revoluta T. revoluta

T. ochraceae T. berterii T. bullata T. rosea T. rosea T. polyantha Nirzka Martínez1,2, Eugenio Santiago1,2, Jackeline Salazar3 1- Biology Department, University of Puerto Rico, Rio Piedras Campus 2- Botanical Garden Herbarium, University of Puerto Rico 3- Biology Department, Autonomous University of Santo Domingo, Dominican Republic

Funded by National Science Foundation, HRD #0734826 and University of Puerto Rico, Rio Piedras Campus