Advanced understanding of phylogenetic relationships, morphological evolution and biogeographic history of the mega-diverse plant genus Myrcia and its relatives (Myrtaceae: Myrteae)
Resource type
Journal article
Creator (person)
Amorim, Bruno
Vasconcelos, Thais
Souza, Gustavo
Alves, Marccus
Antonelli, Alexandre
Lucas, Eve
Date published
September 1, 2019
Abstract
Myrcia is the largest exclusively Neotropical genus of the plant family Myrtaceae with c. 770 species. Although several studies have elucidated the relationships within particular sections of the genus, to date no phylogeny has been produced that includes a broad taxonomic and geographic representation. Here we present a phylogenetic hypothesis of Myrcia and close relatives comprising 253 species and based on two nuclear and seven plastid markers. We combine previously available sequence data with 234 new sequences of the genus Myrcia for this study. We use this phylogeny to investigate the evolution of selected morphological traits and to infer the biogeographic history of the genus. Our results yield a highly supported phylogenetic tree where the Myrceugenia group is sister to the Myrcia and Plinia groups. Five Myrcia species previously considered unplaced emerge in a newly circumscribed clade. The monophyly of two Myrcia sections previously considered uncertain, Aulomyrcia and Gomidesia, are confirmed with strong support. Flowers with free calyx lobes, 2-locular ovaries, and anthers with symmetrical thecae are ancestral features of Myrcia. The Myrcia sect. Gomidesia is highly supported and recovered as monophyletic, with asymmetric anthers that retain their curvature after dehiscence as a morphological synapomorphy. The Atlantic Forest is the most likely ancestral area of the genus and most of its internal clades, from where multiple lineages colonized different regions of South and Central America, in particular the Brazilian Cerrado through multiple unidirectional range expansions. The southern Atlantic Forest is the ancestral area for Myrcia sect. Gomidesia, with lineages reaching the northern Atlantic Forest, Cerrado, Yungas, and other savanna vegetation of South America. Our results provide a solid backbone for further evolutionary and taxonomic work and clarify several previously uncertain relationships in this mega-diverse plant group, and shed light on its geographical range evolution.
Journal title
Molecular Phylogenetics and Evolution
Volume
138
ISSN
1055-7903
eISSN
1095-9513
Rights statement
In Copyright