Systematics of Tanaecium Sw. emend L.G. Lohmann (Bignonieae, Bignoniaceae)

Author(s)

Annelise Frazão Nunes

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2019-08-28

Examining board members

Lucia Garcez Lohmann; Suzana Maria dos Santos Costa; Rafaela Campostrini Forzza; André Olmos Simões

• Advisor: Lucia Garcez Lohmann

Abstract

Tanaecium Sw. emend L.G. Lohmann is a monophyletic genus of Neotropical lianas within the tribe Bignonieae (Bignoniaceae). The genus is characterized by mixed subulate and bromeliad-like prophylls of the axillary buds, putative morphological synapomorphy. In the most recent synopsis of Tanaecium, 17 species were recognized; subsequent works included four new species into the genus leading to 21 species in Tanaecium. Even though some phylogenetic studies sampled representatives of Tanaecium in the past, these studies were not focused on reconstructing the phylogeny of Tanaecium as whole and phylogenetic relationships among its species remain unclear. In this thesis I undertook taxonomic and phylogenetic studies to better understand the systematics and evolution of Tanaecium. The taxonomic component of this thesis resulted in: (i) the description of one new species (Tanaecium decorticans Frazão & L.G. Lohmann), (ii) the combination of one species in Fridericia (i.e., Fridericia mutabilis (Bureau & K. Schum.) Frazão & L.G. Lohmann, (iii) the elucidation of the genus typification, and (iv) a revised synopsis that treated all 21 species for Tanaecium recognized. The phylogenetic component of this thesis combined Sanger and High-Throughput Sequencing (HTS) datasets to reconstruct the most comprehensive phylogeny of the genus to date. This phylogeny was based on sequences of 28 plastomes (16 Tanaecium and 12 outgroups), and 176 sequences generated with Sanger for three molecular markers (i.e., ndhF, rpl32-trnL, and pepC) representing 92 individuals and 17 species of Tanaecium. The 16 plastomes of Tanaecium assembled in this study revealed five different patterns of organization of the Large Single Copy (LSC), Inverted Repeat (IR), and Small Single Copy (SSC) regions. Additionally, four main IR boundary shifts were found, with contractions of the IRs associated to expansions of the SSC and LSC. The topologies reconstructed using the three datasets assembled in this study (i.e., Sanger, plastome, and combined plastome and Sanger) reconstructed four major clades within the core Tanaecium. The topology reconstructed through the analysis of the combined plastome and Sanger dataset provides the most resolved and supported phylogeny of Tanaecium to date. This thesis highlights the importance of in depth studies of individual lineages, including detailed studies of the taxonomy, distribution, and evolutionary relationships, for the understanding of the assembly of the biotas of megadiverse regions such as the Neotropics (AU)

• FAPESP's process: 15/10914-5 - Phylogeny, taxonomic revision, floral evolution and biogeography of Tanaecium Sw. (Bignonieae, Bignoniaceae)
• Grantee: Annelise Frazão Nunes
• Support Opportunities: Scholarships in Brazil - Doctorate