Effect of the Aegean Sea barrier between Europe and Asia on differentiation in Juniperus drupacea (Cupressaceae) KAROLINA SOBIERAJSKA 1 , KRYSTYNA BORATY  NSKA 1 , ANNA JASI  NSKA 1 , MONIKA DERING 1 , TOLGA OK 2 , BOUCHRA DOUAIHY 3 , MAGDA BOU DAGHER-KHARRAT 3 ,  ANGEL ROMO 4 and ADAM BORATY  NSKI 1 * 1 Institute of Dendrology, Polish Academy of Sciences, Parkowa 5, 62-035 K ornik, Poland 2 Department of Forest Botany, Faculty of Forestry, Kahramanmaras Sutcu Imam University, 46100 Kahramanmaras, Turkey 3 Laboratoire Caract  erisation G enomique des Plantes, Facult  e des Sciences, Universit  e Saint-Joseph, Campus Sciences et Technologies, Mar Roukos, Mkalles, BP: 1514 Riad el Solh, Beirut 1107 2050, Lebanon 4 Institute of Botany, Consejo Superior de Investigaciones Cient ıficas-Ajuntament de Barcelona, IBB-CSIC-ICUB, Passeig del Migdia s/n, Parc de Montju€ ıc., 08038 Barcelona, Spain Received 26 June 2015; revised 2 December 2015; accepted for publication 18 December 2015 Juniperus drupacea is an eastern Mediterranean mountain tree with a disjunct geographical range. We hypothesized that this disjunct occurrence (the Peloponnese in Europe and the Taurus and Lebanon Mountains in Asia) should be reflected in the patterns of genetic and morphological diversity and differentiation. Nuclear microsatellite markers (nSSR) and biometric variables of the cones and seeds were examined on material sampled from four populations in Europe and eight in Asia. The Asian populations were characterized by a higher level of genetic diversity than the European populations. The genetic differentiation among populations was moderate but significant (F ST = 0.101, P < 0.001). According to the clustering performed with BAPS, six genetically and geographically groups of populations were found: I and II from the Peloponnese; III from the Taurus Mountains; IV and V from the Anti-Taurus Mountains; and VI from the Lebanon Mountains. The level of genetic differentiation among these six groups (4.30%, P= 0.012) probably reflects long-lasting genetic isolation during the Pleistocene, as limited genetic admixture was found. In accordance with genetic analysis, the biometric investigations indicated a high level of morphological divergence between the European and Asian populations of the species, with further differentiation between the populations from the Taurus and Lebanon Mountains. © 2016 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180, 365–385. ADDITIONAL KEYWORDS: Bayesian clustering – biogeography – biometrics – East Mediterranean – multivariate analyses – nSSR – plant diversity – plant variation – STRUCTURE clustering. INTRODUCTION The Mediterranean Region is one of the global bio- diversity hotspots (Myers et al., 2000), one of the important global centres of endemism and speciation (Greuter, Burdet & Lang, 1984; Tan, Iatrou & John- sen, 2001; Thompson, 2005) and the main Pleis- tocene refugial region for the European Tertiary floras (Hewitt, 1996; M edail & Diadema, 2009). The present geographical ranges of organisms in the east- ern Mediterranean basin result from the geological alternations and subtropical climate cooling, which started with the regression of the Thetys (Thompson, 2005; Popov et al., 2006). The catastrophic effects of the Messinian salinity crisis (Krijgsman et al., 1999) and the Pliocene land-plate movements that formed the Peloponnese and Aegean Islands (Popov et al., 2006; Ivanov et al., 2011) also had a great influence *Corresponding author. E-mail: borata@man.poznan.pl 365 © 2016 The Linnean Society of London, Botanical Journal of the Linnean Society, 2016, 180, 365–385 Botanical Journal of the Linnean Society, 2016, 180, 365–385. With 4 figures Downloaded from https://academic.oup.com/botlinnean/article-abstract/180/3/365/2416573 by guest on 16 June 2020