title: A chloroplast tree for Viburnum (Adoxaceae) and its implications for phylogenetic classification and character evolution.
abstract: • Premise of the study: Despite recent progress, significant uncertainties remain concerning relationships among early-branching lineages within Viburnum (Adoxaceae), prohibiting a new classification and hindering studies of character evolution and the increasing use of Viburnum in addressing a wide range of ecological and evolutionary questions. We hoped to resolve these issues by sequencing whole plastid genomes for representative species and combining these with molecular data previously obtained from an expanded taxon sample.• Methods: We performed paired-end Illumina sequencing of plastid genomes of 22 Viburnum species and combined these data with a 10-gene data set to infer phylogenetic relationships for 113 species. We used the results to devise a comprehensive phylogenetic classification and to analyze the evolution of eight morphological characters that vary among early-branching lineages.• Key results: With greatly increased levels of confidence in most of the early branches, we propose a phylogenetic classification of Viburnum, providing formal phylogenetic definitions for 30 clades, including 13 with names recognized under the International Code of Nomenclature for Algae, Fungi, and Plants, eight with previously proposed informal names, and nine newly proposed names for major branches. Our parsimony reconstructions of bud structure, leaf margins, inflorescence form, ruminate endosperm, extrafloral nectaries, glandular trichomes, palisade anatomy, and pollen exine showed varying levels of homoplasy, but collectively provided morphological support for some, though not all, of the major clades.• Conclusions: Our study demonstrates the value of next-generation plastid sequencing, the ease of creating a formal phylogenetic classification, and the utility of such a system in describing patterns of character evolution.
authors.affiliation: Department of Biology, The College of New Jersey, 2000 Pennington Rd, Ewing, New Jersey 08628 USA.
authors.forename: Wendy L
authors.initials: WL
authors.lastname: Clement
authors.affiliation: Facultad de Ciencias Biológicas and Museo de Historia Natural, UNMSM, Av. Arenales 1256, Apdo. 14-0434, Lima 14, Perú Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, Rhode Island 02912 USA.
authors.forename: Mónica
authors.initials: M
authors.lastname: Arakaki
authors.affiliation: Peabody Museum of Natural History, Yale University, P.O. Box 208105, New Haven, Connecticut 06520 USA.
authors.forename: Patrick W
authors.initials: PW
authors.lastname: Sweeney
authors.affiliation: Department of Ecology and Evolutionary Biology, Brown University, Box G-W, Providence, Rhode Island 02912 USA.
authors.forename: Erika J
authors.initials: EJ
authors.lastname: Edwards
authors.affiliation: Department of Ecology and Evolutionary Biology, Yale University, P.O. Box 208106, New Haven, Connecticut 06520 USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Donoghue
mesh_terms: D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D054627:Genome, Plastid; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D027925:Viburnum / Q000145:classification*
chemical_list: D018742:DNA, Chloroplast; D018744:DNA, Plant
keywords: Viburnum; character evolution; chloroplast DNA; classification; phylogenetic definitions; phylogenetic nomenclature; phylogeny; plastid genome