Details

Autor(en) / Beteiligte

• Medeiros, Maria Cláudia M.P. de
• Lohmann, Lúcia G.

Titel

Phylogeny and biogeography of Tynanthus Miers (Bignonieae, Bignoniaceae)

Ist Teil von

• Molecular phylogenetics and evolution, 2015-04, Vol.85, p.32-40

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Elsevier ScienceDirect Journals Complete

Beschreibungen/Notizen

• [Display omitted] •This study presents the first comprehensive molecular phylogeny of Tynanthus.•This phylogeny reconstructs major relationships among species of the genus.•Most species are monophyletic while two species are paraphyletic.•The phylogeny was used as basis to reconstruct the biogeographic history of the group.•The genus diverged and diversified throughout the Neotropics during the Miocene. The origin of Neotropical biodiversity represents a key question in evolutionary biology. Despite the attempts to decipher the role of ecological and historical factors to present-day distribution patterns, robust phylogenetic studies of Neotropical clades are still needed before a comprehensive picture of the origin of Neotropical biodiversity can be achieved. Tynanthus Miers (Bignonieae, Bignoniaceae) is a well-circumscribed genus of Neotropical lianas with species that are narrowly distributed, except from a few taxa. The genus is characterized by a clove odor, small bilabiate flowers with the two upper lobes almost fused, and fruits with raised margins, all of which represent morphological synapomorphies for this clade. Other distinctive characters are the thecae reflexed forward, the densely pubescent ovaries and the poorly-developed nectariferous disk. The circumscription of the genus has remained constant over the years, despite the problematic limits of most genera of tribe Bignonieae. In this study, we reconstruct the phylogeny of Tynanthus based on two plastid (ndhF and rpl32-trnL) and one nuclear (pepC) markers and use this phylogenetic framework to investigate the biogeographical history of the genus. Our phylogenetic hypothesis provides further support for the monophyly of Tynanthus, and strongly supports a series of infra-generic clades. Most species are reconstructed as monophyletic, while T. cognatus and T. polyanthus are paraphyletic. Biogeographic reconstructions suggest that Tynanthus originated between 9.4 and 21.5Mya, most likely at approximately 15.3Mya. The MRCA of the genus was likely broadly distributed through lowland Amazonia, Western South America and Central America and diversified in the Neotropics during the Miocene. Closely related species are generally distributed within the same biogeographic area, suggesting that niche conservatism has played an important role in the diversification history of the group.