Theoretical and Applied Genetics

, Volume 109, Issue 7, pp 1459–1467

Population genetic structure and phylogeographical pattern of a relict tree fern, Alsophila spinulosa (Cyatheaceae), inferred from cpDNA atpB–rbcL intergenic spacers

  • Yingjuan Su
  • Ting Wang
  • Bo Zheng
  • Yu Jiang
  • Guopei Chen
  • Hongya Gu
Original Paper

DOI: 10.1007/s00122-004-1761-2

Cite this article as:
Su, Y., Wang, T., Zheng, B. et al. Theor Appl Genet (2004) 109: 1459. doi:10.1007/s00122-004-1761-2

Abstract

Sequences of chloroplast DNA (cpDNA) atpB–rbcL intergenic spacers of individuals of a tree fern species, Alsophila spinulosa, collected from ten relict populations distributed in the Hainan and Guangdong provinces, and the Guangxi Zhuang region in southern China, were determined. Sequence length varied from 724 bp to 731 bp, showing length polymorphism, and base composition was with high A+T content between 63.17% and 63.95%. Sequences were neutral in terms of evolution (Tajima’s criterion D=−1.01899, P>0.10 and Fu and Li’s test D*=−1.39008, P>0.10; F*=−1.49775, P>0.10). A total of 19 haplotypes were identified based on nucleotide variation. High levels of haplotype diversity (h=0.744) and nucleotide diversity (Dij=0.01130) were detected in A. spinulosa, probably associated with its long evolutionary history, which has allowed the accumulation of genetic variation within lineages. Both the minimum spanning network and neighbor-joining trees generated for haplotypes demonstrated that current populations of A. spinulosa existing in Hainan, Guangdong, and Guangxi were subdivided into two geographical groups. An analysis of molecular variance indicated that most of the genetic variation (93.49%, P<0.001) was partitioned among regions. Wright’s isolation by distance model was not supported across extant populations. Reduced gene flow by the Qiongzhou Strait and inbreeding may result in the geographical subdivision between the Hainan and Guangdong + Guangxi populations (FST=0.95, Nm=0.03). Within each region, the star-like pattern of phylogeography of haplotypes implied a population expansion process during evolutionary history. Gene genealogies together with coalescent theory provided significant information for uncovering phylogeography of A. spinulosa.

Copyright information

© Springer-Verlag 2004

Authors and Affiliations

  • Yingjuan Su
    • 1
    • 2
  • Ting Wang
    • 1
    • 3
  • Bo Zheng
    • 1
  • Yu Jiang
    • 1
  • Guopei Chen
    • 1
  • Hongya Gu
    • 2
  1. 1.School of Life SciencesZhongshan (Sun Yat-sen) UniversityGuangzhouChina
  2. 2.The National Laboratory of Protein Engineering and Plant Genetic EngineeringPeking UniversityBeijingChina
  3. 3.IBLS/Biochemistry and Molecular Biology, Joseph Black Building Room C3-09University of GlasgowGlasgowUK