title: Phylogenetic relationships in Myrceugenia (Myrtaceae) based on plastid and nuclear DNA sequences.
abstract: Myrceugenia is a genus endemic to South America with a disjunct distribution: 12 species occurring mainly in central Chile and approximately 25 in southeastern Brazil. Relationships are reconstructed within Myrceugenia from four plastid markers (partial trnK-matK, rpl32-trnL, trnQ-5'rps16 and rpl16) and two ribosomal nuclear regions (ETS and ITS) using maximum parsimony and Bayesian analyses. Relationships inferred previously from morphological data are not completely consistent with those from molecular data. All molecular analyses support the hypothesis that Myrceugenia is monophyletic, except for M. fernadeziana that falls outside the genus. Chilean species and Brazilian species form two separate lineages. Chilean species form three early diverging clades, whereas Brazilian species are a strongly supported monophyletic group in a terminal position. Least average evolutionary divergence, low resolution, short branches, and high species diversity found in the Brazilian clade suggest rapid radiation. Geographical distributions and phylogenetic reconstructions suggest that extant Myrceugenia species arose in northern Chile followed by colonization southward and finally to the Juan Fernández Islands and southeastern Brazil.
authors.affiliation: Departamento de Botánica, Universidad de Concepción, Casilla 160-C, Concepción, Chile. jcmurilloa@unal.edu.co
authors.forename: José
authors.initials: J
authors.lastname: Murillo-A
authors.forename: Eduardo
authors.initials: E
authors.lastname: Ruiz-P
authors.forename: Leslie R
authors.initials: LR
authors.lastname: Landrum
authors.forename: Tod F
authors.initials: TF
authors.lastname: Stuessy
authors.forename: Michael H J
authors.initials: MH
authors.lastname: Barfuss
mesh_terms: D001499:Bayes Theorem; D005075:Biological Evolution; D001938:Brazil; D002467:Cell Nucleus / Q000235:genetics*; D002677:Chile; D018742:DNA, Chloroplast / Q000235:genetics*; D021901:DNA, Intergenic / Q000235:genetics*; D049810:Genetic Speciation; D014644:Genetic Variation; D016013:Likelihood Functions; D027822:Myrtaceae / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D058974:Phylogeography; D018087:Plastids / Q000235:genetics*; D017422:Sequence Analysis, DNA; D013045:Species Specificity
chemical_list: D018742:DNA, Chloroplast; D021901:DNA, Intergenic