Molecular phylogeny of Osmanthus (Oleaceae) based on non-coding chloroplast and nuclear ribosomal internal transcribed spacer regions

Abstract

The phylogenetic relationships of Osmanthus Lour. were investigated using the nuclear ribosomal internal transcribed spacer (ITS) regions and non-coding chloroplast regions (psbA-trnH, trnL-F). The two datasets support the conclusion that Osmanthus is polyphyletic, with some species of the subtribe Oleinae nested within Osmanthus. Osmanthus didymopetalus P. S. Green is nested within the clade formed by species of section Osmanthus in two trees. Osmanthus attenuatus P. S. Green, O. yunnanensis P. S. Green, and O. gracilinervis R. L. Lu of traditional section Osmanthus are clearly divergent from other accessions, and do not form a monophyletic group with other Osmanthus accessions. Osmanthus marginatus Hemsl. is embedded in the clade formed by species of section Osmanthus in the ITS tree. In cpDNA trees all species of section Osmanthus are placed in the large clade and all species of section Leiolea formed a group. The taxonomic incongruence among trees for ITS and cpDNA indicate hybridization, as introgression may have occurred among some species of sections Osmanthus and Leiolea. Phylogeny of Osmanthus is discussed in light of molecular and morphological data, and a revised infrageneric classification with three sections (Leiolea, Siphosmanthu, and Osmanthus) is presented. The section Linocieroides is abandoned and united with section Osmanthus.

Museomics illuminate the history of an extinct, paleoendemic plant lineage (Hesperelaea, Oleaceae) known from an 1875 collection from Guadalupe Island, Mexico

“…Both ptDNA and nrDNA topologies corroborate polyphyly of several genera [i.e. Chionanthus (at least three lineages), Osmanthus (two lineages), and Olea (two lineages)] as previously reported in other studies (Besnard et al ., ; Yuan et al ., ; Guo et al ., ). Our analyses also indicate at least three separate Oleinae lineages in America that include the following taxa: (i) Chionanthus filiformis (Brazil), Ch.…”

“…Our ability to generate high‐quality ptDNA and nrDNA sequence data for Hesperelaea allowed us to investigate the phylogenetic placement of this genus within the Oleinae . Phylogenies estimated separately with ptDNA and nrDNA data corroborate polyphyly of several Oleinae genera, as previously shown by other authors (Besnard et al ., ; Yuan et al ., ; Guo et al ., ; Hong‐Wa & Besnard, ). The tree topologies for subtribe Oleinae based on ptDNA vs. nrDNA data, however, show deep incongruence, as very similarly found in a previous study on this group (Hong‐Wa & Besnard, ).…”

“…Hesperelaea belongs to tribe Oleeae , subtribe Oleinae (Wallander & Albert, ). The phylogenetic relationships of Oleeae have been investigated using plastid and nuclear ribosomal regions with various degrees of resolution, and recent studies have mainly focused on specific lineages such as Fraxinus (Jeandroz, Roy & Bousquet, ; Wallander, ; Arca et al ., ; Hinsinger et al ., , ), Syringa – Ligustrum (Kim & Jansen, ; Li, Alexander & Zhang, ), Olea (Besnard et al ., ), Osmanthus (Yuan et al ., ; Guo et al ., ), and Noronhia–Chionanthus (Hong‐Wa & Besnard, ). These studies revealed that several Oleeae genera (e.g.…”

“…Chionanthus, Ligustrum , Olea L., and Osmanthus ) are paraphyletic or polyphyletic, and there is a need for taxonomic revisions, in particular of subtribe Oleinae (e.g. Besnard et al ., ; Yuan et al ., ; Guo et al ., ; Hong‐Wa & Besnard, ). In addition, many Oleaceae species are rare or micro‐endemic, and some are known only from one or two old herbarium records (for Noronhia Stadtm.…”

Floral morphology resolves the taxonomy of <i>Camellia</i> L. (Theaceae) Sect. <i>Oleifera</i> and Sect. <i>Paracamellia</i>

“…A Bayesian Analysis (BA) was performed on standard data set, using a General Time Reversible (GTR) model (nst=6; rates=invgamma) with gammadistribution rate variation and a proportion of invariant sites, and one million generations of the Markov Chain Monte Carlo (MCMC) chains in two independent runs (Yuan et al, 2010). All other trees sampled were used to calculate a strict consensus tree, thus yielding the Posterior Probability (PP).…”