Abstract Detail

Systematics

Frazão, Annelise [1], Lohmann, Lucia [1].

Using molecular and morphological data to investigate the Tanaecium dichotomum species complex (Bignonieae, Bignoniaceae).

Tanaecium is a Neotropical genus that belongs to the trumpet-creeper plant family (Bignoniaceae). The genus includes 21 species of lianas with variable morphological features, especially in floral traits. The genus is monophyletic and most of its species are well circumscribed, except the Tanaecium dichotomum species complex, which was recovered as polyphyletic in a recent molecular phylogeny of the genus based on NGS and Sanger sequencing data. Morphological data corroborate the hypothesis that T. dichotomum represents a species complex. To investigate the T. dichotomum diversity, we conducted a phylogenetic study of Tanaecium based on three molecular markers (ndhF, rpl32-trnL, and PepC) and a broad sampling of individuals within the T. dichotomum species complex. To test species limits within this group we used the Bayesian multispecies coalescent approach implemented in the software Bayesian Phylogenetics and Phylogeography (BPP). We tested five models established based on morphology that treated T. dichotomum as one to five separate species. The worse posterior probability (PP) was for the model that treated T. dichotomum as a single species, supporting the hypothesis of T. dichotomum as a species complex. The models that recognize two or three species did not differ suggesting that two or three distinguishable morphotypes are also supported as separate units by molecular data. Both models strongly support the recognition of one of the Central South American morphotypes of T. dichotomum as a separate species. Our results support the hypothesis that the Tanaecium diversity is underestimated and that more detailed morphological and molecular studies are crucial for more accurate species delimitation of the T. dichotomum species complex.

1 - Universidade de São Paulo, Departamento de Botânica, Rua do Matão, 277, Cidade Universitária, São Paulo, SP, 05580-090, BRA

Keywords:
Tanaecium
species delimitation
Bayesian multispecies coalescent approach
Lianas.

Presentation Type: Oral Paper
Session: SYS3, Systematics III: Cooley Award presentations
Location: Virtual/Virtual
Date: Wednesday, July 29th, 2020
Time: 11:15 AM
Number: SYS3006
Abstract ID:670
Candidate for Awards:George R. Cooley Award