title: Tectonic and climatic impacts on the biota within the Red River Fault, evidence from phylogeography of Cycas dolichophylla (Cycadaceae).
abstract: Dramatic crustal deformation and river incision in Southwest China induced by the Indo-Asian collision have long been argued to contribute to the complicated landscapes, heterogeneous environment and abundant biodiversity in this region. However, biological impacts in promoting intraspecific phylogeographical subdivision and divergence along the Red River Fault zone (RRF) remain poorly understood. To investigate the possible biological effects of tectonic movements and environment variations within the RRF, the phylogeography of Cycas dolichophylla-an endemic but widely distributed Cycas in Southwest China and North Vietnam along the RRF were carried out based on four chloroplast DNA intergenic spacers (cpDNA), three nuclear DNA sequences (nDNA) and 16 simple sequence repeat variations (SSR). Two different phylogeographical patterns were detected: a Southwest-Northeast break across the RRF disclosed by chlorotypes and a China-Vietnam separation revealed by SSR. A Bayesian skyline plot from cpDNA data demonstrated a historical increasing, but a recent declining, dynamic in population size during the Pleistocene. Consequently, we infer it is the local environmental variation during Cenozoic that contributed to the complex landscape and microclimate mosaics, facilitating speciation and divergence of C. dolichophylla. Subsequently, the Quaternary climatic fluctuations coupled with human activities profoundly influenced the genetic structure and demographic history of this species.
authors.affiliation: Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.|University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.affiliation: Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, China.
authors.forename: Xun
authors.initials: X
authors.lastname: Gong
mesh_terms: D001483:Base Sequence; D001499:Bayes Theorem; D058448:Biota; D002681:China; D002980:Climate; D029784:Cycas / Q000145:classification*; D018742:DNA, Chloroplast / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D055593:Geological Phenomena; D006239:Haplotypes; D018895:Microsatellite Repeats / Q000235:genetics; D010802:Phylogeny; D058974:Phylogeography
chemical_list: D018742:DNA, Chloroplast