J Syst Evol ›› 2010, Vol. 48 ›› Issue (3): 153-160.DOI: 10.1111/j.1759-6831.2010.00073.x

• Research Articles •     Next Articles

Allopatric divergence and regional range expansion of Juniperus sabina in China

1Yu-Peng GUO* 1Ru ZHANG* 1Cui-Yun CHEN 2Dang-Wei ZHOU 1Jian-Quan LIU   

  1. 1(Division of Molecular Ecology, Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, China)
    2(Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining 810000, China)
  • Received:2009-09-16 Published:2010-05-18

Abstract: In this study, we aimed to study the phylogeographical pattern of Juniperus sabina, a shrub species commonly occurring in the northern, northwestern and western China. We sequenced three chloroplast DNA fragments (trnL-trnF, trnS-trnG and trnD-trnT) for 137 individuals from 16 populations of this species. Five chloroplast DNA (cpDNA) chlorotypes (A, B, C, D and E) were identified and they showed no overlapping distribution. The population subdivision is very high (GST = 0.926, NST = 0.980), suggesting distinct phylogeographical structure (NST > GST, P < 0.05). Phylogenetic analyses of the five chlorotypes clustered into three clades which were consistent with their respective distributions in three separate regions: northern Xinjiang, western Xinjiang and northern-northwestern China. However, within each region, the inter-population differentiation is extremely low. These results as well as statistical tests suggested distinct allopatric differentiations between regional populations and independent glacial refugia for postglacial recolonization. The deserts developed during the late Quaternary might have acted as the effective barriers to promote genetic differentiation among these regions. However, the low diversity dominated by the single chlorotype within each fragmented region suggested that all current populations were derived from a common regional range expansion respectively.

Key words: cpDNA, genetic diversity, Juniperus sabina, phylogeography, range expansion.