J Syst Evol ›› 2011, Vol. 49 ›› Issue (2): 108-119.DOI: 10.1111/j.1759-6831.2011.00117.x

• Research Articles • Previous Articles     Next Articles

Chloroplast DNA variation and phylogeography of Ligularia tongolensis (Asteraceae), a species endemic to the Hengduan Mountains Region of China

1,2Jin-Feng WANG 1Yue-Zhi PAN 1Xun GONG* 3Yu-Chung CHIANG* 4Chiaki KURODA   

  1. 1(Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, China)
    2(Graduate School of the Chinese Academy of Sciences, Beijing 100049, China)
    3(Department of Biological Sciences, National Sun Yat-Sen University, Kaohsiung 80424, Taiwan, China)
    4(Department of Chemistry, Rikkyo University, Tokyo 171-8501, Japan)
  • Received:2010-09-14 Published:2011-03-10

Abstract: In this research, we aimed to study the genetic variation and phylogeographic pattern of Ligularia tongolensis, a perennial herb endemic to the Hengduan Mountains region of China. We sequenced two chloroplast DNA (cpDNA) intergenic spacers (trnQ-5′rps16, trnL-rpl32) in 140 individuals from 14 populations of three groups (Jinshajiang vs. Yalongjiang vs. Wumeng) within this species range. High levels of haplotype diversity (Hd = 0.814) and total genetic diversity (Ht = 0.862) were detected at the species level, based on a total of 12 haplotypes identified. Low levels of intrapopulation diversity (Hs = 0.349), high levels of genetic divergence (Gst = 0.595, Nst = 0.614, Fst = 0.597), and the absence of isolation by distance tests were also found in L. tongolensis. Furthermore, H2 and H5, the dominant haplotypes that located at internal nodes and deviated from extinct ancestral haplotype in the network, were found to be shared between Jinshajiang and Yalongjiang groups. These results indicate that past fragmentation may be the important factor responsible for the present phylogeographical pattern of L. tongolensis. Meanwhile, the locations occupied by each group might have served as independent refugia for L. tongolensis during the Quaternary glaciation. Unimodal mismatch distribution and star-like genealogies indicated this species underwent past demographic expansion events, with expansion ages of 274 ka BP.

Key words: genetic variation, Ligularia tongolensis, phylogeography, Quaternary glaciation.