title: Phylogeography and genetic structure of a Tertiary relict tree species, Tapiscia sinensis (Tapisciaceae): implications for conservation.
abstract: OBJECTIVE
  The phylogeography of plant species in sub-tropical China remains largely unclear. This study used Tapiscia sinensis, an endemic and endangered tree species widely but disjunctly distributed in sub-tropical China, as a model to reveal the patterns of genetic diversity and phylogeographical history of Tertiary relict plant species in this region. The implications of the results are discussed in relation to its conservation management.
  
  
  METHODS
  Samples were taken from 24 populations covering the natural geographical distribution of T. sinensis. Genetic structure was investigated by analysis of molecular variance (AMOVA) and spatial analysis of molecular variance (SAMOVA). Phylogenetic relationships among haplotypes were constructed with maximum parsimony and haplotype network methods. Historical population expansion events were tested with pairwise mismatch distribution analysis and neutrality tests. Species potential range was deduced by ecological niche modelling (ENM).
  
  
  RESULTS
  A low level of genetic diversity was detected at the population level. A high level of genetic differentiation and a significant phylogeographical structure were revealed. The mean divergence time of the haplotypes was approx. 1·33 million years ago. Recent range expansion in this species is suggested by a star-like haplotype network and by the results from the mismatch distribution analysis and neutrality tests.
  
  
  CONCLUSIONS
  Climatic oscillations during the Pleistocene have had pronounced effects on the extant distribution of Tapiscia relative to the Last Glacial Maximum (LGM). Spatial patterns of molecular variation and ENM suggest that T. sinensis may have retreated in south-western and central China and colonized eastern China prior to the LGM. Multiple montane refugia for T. sinense existing during the LGM are inferred in central and western China. The populations adjacent to or within these refugia of T. sinense should be given high priority in the development of conservation policies and management strategies for this endangered species.
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan 430074, Hubei, China and.
authors.forename: Jinju
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan 430074, Hubei, China and.
authors.forename: Zuozhou
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Botany, California Academy of Sciences, 55 Music Concourse Drive, San Francisco, CA 94118, USA.
authors.forename: Peter W
authors.initials: PW
authors.lastname: Fritsch
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan 430074, Hubei, China and.
authors.forename: Hua
authors.initials: H
authors.lastname: Tian
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan 430074, Hubei, China and.
authors.forename: Aihong
authors.initials: A
authors.lastname: Yang
authors.affiliation: Key Laboratory of Plant Germplasm Enhancement and Speciality Agriculture, Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan 430074, Hubei, China and yaox@wbgcas.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yao
mesh_terms: D002681:China; D003247:Conservation of Natural Resources; D018742:DNA, Chloroplast / Q000235:genetics / Q000378:metabolism; D021903:DNA, Ribosomal Spacer / Q000235:genetics / Q000378:metabolism; D014644:Genetic Variation; D006239:Haplotypes; D019684:Magnoliopsida / Q000145:classification* / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D010802:Phylogeny; D058974:Phylogeography; D063148:Plant Dispersal; D017422:Sequence Analysis, DNA
chemical_list: D018742:DNA, Chloroplast; D021903:DNA, Ribosomal Spacer
keywords: Conservation; Pleistocene climate change; Staphyleaceae; Tapiscia sinensis; Tapisciaceae; Tertiary relict tree species; ecological niche modelling; local range expansion; multiple refugia; sub-tropical China