title: Phylogeography of the endangered orchid Dendrobium moniliforme in East Asia inferred from chloroplast DNA sequences.
abstract: The aim of the current study was to elucidate the phylogeographic history of Dendrobium moniliforme, an endangered orchid species, based on two chloroplast DNA (cpDNA) markers (trnC-petN and trnE-trnT). One hundred and thirty-five samples were collected from 18 natural populations of D. moniliforme covering the entire range of the Sino-Japanese Floristic Region (SJFR) of East Asia. A total of 35 distinct cpDNA haplotypes were identified in these populations, of which 23 haplotypes were each present in only one sample and thus restricted to a single population. The significantly larger NSTvalue (0.586) than GST(0.328) (p < 0.05) demonstrated the presence of strong phylogeographic structure. Phylogenetic analyses indicated that all haplotypes were clustered into two lineages. The genetic diversity of D. moniliforme was high at the species level, reflected in its haplotype diversity (Hd=0.8862), nucleotide diversity (Pi=0.00361), total genetic diversity (HT=0.9011), and significant differentiation (ΦST=0.5482). Based on mismatch distribution analysis and neutrality tests, population expansion was evident in all sampled populations and also in all populations sampled in mainland China. Three refuge areas were identified, one each in southwestern China, central-southeastern China, and the CKJ (Taiwan, Japan and Korea) Islands. The results supported the hypothesis that glacial refugia were maintained on different spatial-temporal scales in the SJFR during the last glacial maximum or earlier cold periods, suggesting that Quaternary refugial isolation promoted allopatric speciation of D. moniliforme in East Asia.
authors.affiliation: a College of Life Sciences , Nanjing Normal University , Nanjing , China.|b College of Life Sciences , Anhui Science and Technology University , Fengyang , China.
authors.forename: Meirong
authors.initials: M
authors.lastname: Ye
authors.affiliation: a College of Life Sciences , Nanjing Normal University , Nanjing , China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: a College of Life Sciences , Nanjing Normal University , Nanjing , China.
authors.forename: Qingyun
authors.initials: Q
authors.lastname: Xue
authors.affiliation: c Nanjing Institute for Comprehensive Utilization of Wild Plants , Nanjing , China.
authors.forename: Beiwei
authors.initials: B
authors.lastname: Hou
authors.affiliation: d College of Physical Sciences , Nanjing Normal University , Nanjing , China.
authors.forename: Jing
authors.initials: J
authors.lastname: Luo
authors.affiliation: a College of Life Sciences , Nanjing Normal University , Nanjing , China.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Ding
mesh_terms: D018742:DNA, Chloroplast; D031667:Dendrobium / Q000235:genetics*; D056727:Endangered Species; D005202:Asia, Eastern; D014644:Genetic Variation; D010802:Phylogeny; D058974:Phylogeography; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast
keywords: Dendrobium moniliforme; cpDNA; haplotype; phylogeography; refuge