Phylogeography of Cyananthus delavayi （Campanulaceae） in Hengduan Mountains inferred from variation in nuclear and chloroplast DNA sequences  

作　　者：Guo-Dong LI Liang-Liang YUE Hang SUN Zi-Gang QIAN 

机构地区：[1]Key Laboratory of Biodiversity and Biogeography,Kunming Institute of Botany,Chinese Academy of Sciences,Kunming 650200 [2]Graduate University of Chinese Academy of Sciences,Beijing 100049,China [3]Yunnan University of Traditional Chinese Medicine,Kunming 650500,China

出　　处：《Journal of Systematics and Evolution》2012年第4期305-315,共11页植物分类学报（英文版）

基　　金：Acknowledgements We sincerely thank Prof. Jian- Quan LIU, Dr. Ying-Xiong QIU, and two anonymous reviewers for comments and suggestions to improve the manuscript. We thank Dr. Hong-Guang ZHA and Dr. Yong-Hong ZHANG for assistance with the molecular techniques and helpful comments on this manuscript. We are also grateful to Dr. Yang NIU, Mr. Zhuo ZHOU, and Mr. Bo XU for help with the field survey and leaf collection. This study was supported by a Na- tional Natural Science Foundation of China and Yunnan Natural Science Foundation Joint Project （Grant No. Ul136601）, the 100 Talents Program of the Chinese Academy of Sciences （No. 2011312D11022）, and the National Natural Science Foundation of China （Grant No. 31061160184 and No. 40930209 to Prof. Hang SUN; 30960501 to Prof. Zi-Gang QIAN）.

摘　　要：Phylogeographic studies on alpine plants endemic to the Hengduan Mountains of the southeastern Qinghai-Tibet Plateau are still limited in number. In this study, we used sequence variation of one nuclear gene （ncpGS, which encodes the chloroplastic glutamine synthetase） and in two chloroplast DNA segments to investigate the phylogeographic structure and population demographic history of Cyananthus delavayi, a narrow-range species endemic to this region. We identified eight chlorotypes and 16 nuclear genotypes in a survey of 10 populations sampled throughout the range of the species. The results of both phylogenetic and network analyses suggested that the genealogical relationships of both chlorotypes and nuclear genotypes showed a clear geographical correlation. High total genetic diversity, low levels of within-population diversity, and strong population differentiation （chloroplast DNA： hT = 0.827, hs = 0.087, NST = 0.899, GST = 0.895; nuclear DNA： hT = 0.910, hs ~ 0.348, NST = 0719, GST = 0.618） were identified. Based on the mismatch distribution analyses, no evidence of recent demographic population expansion was found for this species. Nested clade analyses of both chlorotypes and nuclear genotypes indicated that restricted gene flow resulting from isolation by distance and allopatric fragmentation were likely to have been the major processes that shaped their present-day spatial distribution. Our dating of the genetic divergences between three major geographic lineages suggested that the largest glaciation of the early Quaternary developed in the Qinghai-Tibet Plateau and mountainous isolation may have together led to deep intraspecific vicariance within this species.Phylogeographic studies on alpine plants endemic to the Hengduan Mountains of the southeastern Qinghai-Tibet Plateau are still limited in number. In this study, we used sequence variation of one nuclear gene （ncpGS, which encodes the chloroplastic glutamine synthetase） and in two chloroplast DNA segments to investigate the phylogeographic structure and population demographic history of Cyananthus delavayi, a narrow-range species endemic to this region. We identified eight chlorotypes and 16 nuclear genotypes in a survey of 10 populations sampled throughout the range of the species. The results of both phylogenetic and network analyses suggested that the genealogical relationships of both chlorotypes and nuclear genotypes showed a clear geographical correlation. High total genetic diversity, low levels of within-population diversity, and strong population differentiation （chloroplast DNA： hT = 0.827, hs = 0.087, NST = 0.899, GST = 0.895; nuclear DNA： hT = 0.910, hs ~ 0.348, NST = 0719, GST = 0.618） were identified. Based on the mismatch distribution analyses, no evidence of recent demographic population expansion was found for this species. Nested clade analyses of both chlorotypes and nuclear genotypes indicated that restricted gene flow resulting from isolation by distance and allopatric fragmentation were likely to have been the major processes that shaped their present-day spatial distribution. Our dating of the genetic divergences between three major geographic lineages suggested that the largest glaciation of the early Quaternary developed in the Qinghai-Tibet Plateau and mountainous isolation may have together led to deep intraspecific vicariance within this species.

关 键 词：chloroplast DNA Cyananthus delavayi Hengduan Mountains ncpGS PHYLOGEOGRAPHY VICARIANCE 

分 类 号：Q523[生物学—生物化学] S512.101[农业科学—作物学]