title: Phylogenetic relationships in the Gesnerioideae (Gesneriaceae) based on nrDNA ITS and cpDNA trnL-F and trnE-T spacer region sequences.
abstract: The Gesnerioideae includes most of the New World members of the Gesneriaceae family and is currently considered to include five tribes: Beslerieae, Episcieae, Gesnerieae, Gloxinieae, and Napeantheae. This study presents maximum parsimony and maximum likelihood phylogenetic analyses of nuclear ribosomal DNA internal transcribed spacer regions (ITS), and the chloroplast DNA trnL intron, trnL-trnF intergenic spacer region, and trnE-trnT intergenic spacer region sequences. The ITS and cpDNA data sets strongly support the monophyly of a Beslerieae/Napeantheae clade; an Episcieae clade; a Gesnerieae clade; a Gloxinieae clade minus Sinningia, Sinningia relatives, and Gloxinia sarmentiana; and a Sinningia/Paliavana/Vanhouttea clade. This is the first study to provide strong statistical support for these tribes/clades. These analyses suggest that Sinningia and relatives should be considered as a separate tribe. Additionally, generic relationships are explored, including the apparent polyphyly of Gloxinia. Chromosome number changes are minimized on the proposed phylogeny, with the exception of the n = 11 taxa of the Gloxinieae. Scaly rhizomes appear to have been derived once in the Gloxinieae sensu stricto. The number of derivations of the inferior ovary is unclear: either there was one derivation with a reversal to a superior ovary in the Episcieae, or there were multiple independent derivations of the inferior ovary.
authors.affiliation: Laboratory of Molecular Systematics, National Museum of Natural History, Smithsonian Institution, Washington, DC 20560 USA;
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Zimmer
authors.forename: Eric H
authors.initials: EH
authors.lastname: Roalson
authors.forename: Laurence E
authors.initials: LE
authors.lastname: Skog
authors.forename: John K
authors.initials: JK
authors.lastname: Boggan
authors.forename: Alexander
authors.initials: A
authors.lastname: Idnurm