Phylogeographic pattern of the European forest grass species Hordelymus europaeus: cpDNA evidence Hana Dvoˇ ra ´ kova ´ a,n , Toma ´ˇ s Fe ´r a , Karol Marhold a,b a Department of Botany, Faculty of Science, Charles University, Bena ´tska ´ 2, CZ-128 01 Praha 2, Czech Republic b Institute of Botany, Slovak Academy of Sciences, Du ´bravska ´ cesta 9, SK-845 23 Bratislava, Slovak Republic article info Article history: Received 18 February 2009 Accepted 14 August 2009 Keywords: Central Europe cpDNA sequences Fagus sylvatica Glacial refugia Phylogeography Poaceae abstract The phylogeographical structure of the European forest grass Hordelymus europaeus (Poaceae) was studied by sequencing three non-coding regions of chloroplast DNA. Forty-three populations within the entire natural distribution area were analysed. The greatest haplotype variation and divergence were revealed on Balkan and Apennine Peninsula, suggesting main glacial refugia in these regions. Among southern refugia, probably only the Balkans could have remarkably contributed to postglacial re- colonisation of the northern parts of Europe. A distinctly different haplotype group found on the Crimean Peninsula and in central Italy may represent either relicts of a previously more widespread ancestor or result of long-distance dispersal. The phylogeographical pattern found in H. europaeus is to certain extent similar with that found in Fagus sylvatica. This might imply a partly common postglacial colonisation history of these ecologically narrowly tied species. Nevertheless, unlike in the case of F. sylvatica, we did not found convincing evidence for the existence of Central European glacial refugia for H. europaeus. & 2009 Elsevier GmbH. All rights reserved. Introduction Quaternary climatic changes in Europe are considered to be one of the most important factors affecting the present geogra- phical distribution and variation of organisms (Comes and Kadereit, 1998; Taberlet et al., 1998). Repeated fluctuations of mean temperature and precipitation have caused species migra- tion processes, which can be inferred only indirectly on the basis of palaeontological or phylogeographical evidence (Hewitt, 1999). Recently, several molecular studies have extended our previous knowledge based on pollen and macrofossil data (e.g., Palme ´ and Vendramin, 2002; Palme ´ et al., 2003; Magri et al., 2006). Moreover, in the case of insufficient or missing fossil evidence, phylogeographical molecular methods remain as the only alter- native to formulate hypotheses about glacial/postglacial changes in the distribution patterns of species (e.g. Cooper et al., 1995; Tyler, 2002; Fe ´r et al., 2007). The first phylogeographical studies on a European scale focused mostly on tree species and mammals (Taberlet et al., 1998; Hewitt, 1999). Results of these studies enabled the formulation of certain generalisations of postglacial migration routes, with common areas of secondary contacts and main glacial refugia situated on the Balkan, Apennine and Iberian Peninsulas as the main sources of postglacial colonisation (Hewitt, 1999). More recently, studies have been carried out on finer scales, extending the number of investigated species and using a broader assortment of non-molecular and molecular methods. This has revealed more complex phylogeographical patterns such as detection of species survival in areas where their occurrence during unfavorable climatic periods in the Quaternary period was not expected (Shonil and Willis, 2008). The possibility that woody plant species survived in more northerly regions than originally supposed opened the discussion about the existence of Central European refugia (Willis et al., 2000; Carcaillet and Vernet, 2001; Stewart and Lister, 2001; Willis and van Andel, 2004; Magri et al., 2006; Shonil and Willis, 2008). Moreover, the results of several studies support the presence of trees during full-glacial times in Central and eastern Europe, suggesting the occurrence of small isolated populations of trees in buffered local microclimates (like valley systems) in this area (Willis et al., 2000; Stewart and Lister, 2001; Willis and van Andel, 2004; Jankovska ´ and Pokorny ´ , 2008). For Fagus sylvatica L., fossil and genetic data taken together, support the existence of glacial refugia in Central Europe as an independent source for postglacial recolonisation of surrounding areas. Diffuse spread from several small and scattered populations is assumed (Magri et al., 2006; Magri, 2008). A similar pattern was also detected for Betula pendula Roth (Palme ´ et al., 2003; Maliouchenko et al., 2007). According to molecular analyses, a diversity centre indicating a ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.de/flora Flora 0367-2530/$ - see front matter & 2009 Elsevier GmbH. All rights reserved. doi:10.1016/j.flora.2009.12.029 n Corresponding author. E-mail addresses: ha.d@centrum.cz (H. Dvoˇ ra ´ kova ´ ), tomas.fer@centrum.cz (T. Fe ´ r), karol.marhold@savba.sk (K. Marhold). Flora 205 (2010) 418–423