title: Molecular phylogeny of Koenigia L. (Polygonaceae: Persicarieae): implications for classification, character evolution and biogeography.
abstract: To examine the phylogenetic relationships of Koenigia sensu lato (Polygonaceae), 43 samples representing all species of Koenigia and closely related taxa (e.g., Aconogonon, Bistorta, and Persicaria) were sequenced for nuclear ITS and four plastid regions (trnL-F, atpB-rbcL, rbcL, and rpl32-trnL((UAG))). Phylogenetic analyses indicate that Koenigia recognized by Hedberg is paraphyletic and that the basal species K. delicatula should be reassigned to a separate new genus. Based on these findings, we further propose that the genus Koenigia sensu lato be circumscribed to include five species. Ancestral state reconstruction showed that the pollen apertures likely evolved in parallel in the Aconogonon-Koenigia-Bistorta clade and Persicaria clade and that tricolpate pollen is most likely to be the ancestral state. Quincuncial aestivation likely evolved during the early evolution of Koenigia and its close relatives. Our findings suggest that the uplift of the Himalayas has played an important role in promoting species diversification of Koenigia. Koenigia islandica expanded its range during Pleistocene glacial cycles by tracking changes in newly available habitats.
authors.affiliation: Laboratory of Subtropical Biodiversity, Jiangxi Agricultural University, Nanchang 330045, PR China.
authors.forename: Deng-Mei
authors.initials: DM
authors.lastname: Fan
authors.forename: Jia-Hui
authors.initials: JH
authors.lastname: Chen
authors.forename: Ying
authors.initials: Y
authors.lastname: Meng
authors.forename: Jun
authors.initials: J
authors.lastname: Wen
authors.forename: Jin-Ling
authors.initials: JL
authors.lastname: Huang
authors.forename: Yong-Ping
authors.initials: YP
authors.lastname: Yang
mesh_terms: D001499:Bayes Theorem; D002681:China; D018742:DNA, Chloroplast / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D019143:Evolution, Molecular; D016013:Likelihood Functions; D008957:Models, Genetic; D010802:Phylogeny; D011058:Pollen / Q000033:anatomy & histology; D019664:Polygonaceae / Q000033:anatomy & histology / Q000145:classification* / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D018744:DNA, Plant; D021903:DNA, Ribosomal Spacer
keywords: Biogeographic diversification; Character evolution; Classification; Koenigia; The Himalayan region