title: Analysis of nuclear microsatellites reveals limited differentiation between Colchic and Hyrcanian populations of the wind-pollinated relict tree Zelkova carpinifolia (Ulmaceae).
abstract: •
  
  
  OBJECTIVE
  The Caucasus represents one of the world's biodiversity hotspots and includes the climatic refugia Hyrcan on the southern coast of the Caspian Sea and Colchis on the eastern coast of the Black Sea, where different species survived during the Quaternary climatic oscillations. We evaluated the genetic diversity of the relict tree Zelkova carpinifolia shared between the two refugia and distributed throughout the Caucasus and adjacent areas.•
  
  
  METHODS
  Specimens were collected from 30 geographical sites in Azerbaijan, Georgia, Iran, and Turkey and screened for variability at eight nuclear microsatellite loci. The genetic diversity among and within populations was assessed using a set of statistical measures.•
  
  
  RESULTS
  We detected 379 different genotypes from a total of 495 individuals with varying degrees of clonal reproduction at the different sites. Low to intermediate levels of genetic diversity were observed at all sites, and strong differentiation between sampling sites was absent. In addition, we observed no clear genetic differentiation between the Colchis and Hyrcan. Bayesian clustering of the genotypes revealed three populations with high levels of admixture between the sampling sites.•
  
  
  CONCLUSIONS
  The lack of strong genetic structure of studied populations of Z. carpinifolia contrasts with a previous study based on chloroplast markers and suggests that long-distance pollen dispersal is an important factor of gene flow among populations of Z. carpinifolia. The present study does not reveal any particular site with particularly isolated genotypes that would deserve more attention for conservation purposes than others, although some sites should be considered for further investigation.
authors.affiliation: Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin, 14195 Berlin, Germany Institute of Botany, Azerbaijan National Academy of Sciences, AZ1073 Baku, Azerbaijan.
authors.forename: Elmira H
authors.initials: EH
authors.lastname: Maharramova
authors.affiliation: Hirkan National Park, AZ4235 Lankaran, Azerbaijan.
authors.forename: Hajiaga M
authors.initials: HM
authors.lastname: Safarov
authors.affiliation: Department of Biology and Botanic Garden, University of Fribourg, CH-1700 Fribourg, Switzerland Natural History Museum, CH-1700 Fribourg, Switzerland.
authors.forename: Gregor
authors.initials: G
authors.lastname: Kozlowski
authors.affiliation: Botanischer Garten und Botanisches Museum Berlin-Dahlem, Freie Universität Berlin, 14195 Berlin, Germany Institut für Biologie-Botanik, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Borsch
authors.affiliation: Institut für Biologie-Botanik, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: Ludo A
authors.initials: LA
authors.lastname: Muller
mesh_terms: D002467:Cell Nucleus / Q000235:genetics; D003247:Conservation of Natural Resources; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D051456:Gene Flow; D014644:Genetic Variation; D018895:Microsatellite Repeats; D063148:Plant Dispersal; D054817:Pollination; D000068236:Refugium; D034401:Ulmaceae / Q000235:genetics* / Q000502:physiology
chemical_list: D018744:DNA, Plant
keywords: Caucasus biodiversity hotspot; Colchis; Hyrcan; Ulmaceae; Zelkova carpinifolia; gene flow; relict tree