Articles containing the keyword 'marginal populations'

Populations at species’ range margins are expected to show lower genetic diversity than populations at the core of the range. Yet, long-lived, widespread tree species are expected to be resistant to genetic impoverishment, thus showing comparatively high genetic diversity within populations and low differentiation among populations. Here, we study the distribution of genetic variation in the pedunculate oak (Quercus robur L.) at its range margin in Finland at two hierarchical scales using 15 microsatellite loci. At a regional scale, we compared variation within versus among three oak populations. At a landscape scale, we examined genetic structuring within one of these populations, growing on an island of ca 5 km². As expected, we found the majority of genetic variation in Q. robur to occur within populations. Nonetheless, differentiation among populations was markedly high (F_ST = 0.12) compared with values reported for populations of Q. robur closer to the core of its range. At the landscape level, some spatial and temporal sub-structuring was observed, likely explained by the history of land-use on the island. Overall, Q. robur fulfils the expectation of the central-marginal hypothesis of high differentiation among marginal populations, but the notable population differentiation has most likely been influenced also by the long, ongoing fragmentation of populations. Finnish oak populations may still be adjusting to the drastic habitat changes of the past centuries. Preservation of genetic variation within the remaining stands is thus an important factor in the conservation of Q. robur at its range margin.

• Pohjanmies, University of Helsinki, Department of Agricultural Sciences, Spatial Foodweb Ecology Group, P.O. Box 27, FI-00014 University of Helsinki, Finland; University of Jyväskylä, Department of Biological and Environmental Sciences, P.O. Box 35, FI-40014 University of Jyväskylä, Finland E-mail: tahti.t.pohjanmies@jyu.fi
• Elshibli, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland; University of Helsinki, Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: sakina.elshibli@helsinki.fi
• Pulkkinen, Natural Resources Institute Finland (Luke), Green technology, Haapastensyrjäntie 34, FI-12600 Läyliäinen, Finland E-mail: pertti.pulkkinen@luke.fi
• Rusanen, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mari.rusanen@luke.fi
• Vakkari, Natural Resources Institute Finland (Luke), Green technology, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pekka.vakkari@luke.fi
• Korpelainen, University of Helsinki, Department of Agricultural Sciences, P.O. Box 27, FI-00014 University of Helsinki, Finland E-mail: helena.korpelainen@helsinki.fi
• Roslin, University of Helsinki, Department of Agricultural Sciences, Spatial Foodweb Ecology Group, P.O. Box 27, FI-00014 University of Helsinki, Finland; Swedish University of Agricultural Sciences, Department of Ecology, P.O. Box 7044, SE-750 07 Uppsala, Sweden E-mail: tomas.roslin@helsinki.fi

Vaccinium myrtillus L., Vaccinium uliginosum L. and Vaccinium vitis-idaea L. are perennial, cold-adapted clonal shrubs distributed throughout Europe, northern Asia and North America. Due to their usage in food (berries) and pharmaceutical industry (berries and leaves), their natural populations are exposed to anthropogenic and other impacts that affect their genetic make-up. We analyzed 14 fragmentary distributed and small-sized peripheral populations of these species from the Balkans, which represents the southeastern-European marginal area of their wide European distributions, using RAPD molecular markers. The contemporary genetic patterns in all three species within the Balkans were generally similar, and in comparison to previous reports on populations of these species found in northward Europe, where they have a more continuous distribution, the levels of genetic diversity were more or less halved, genetic differentiation was several times higher, gene flow exceptionally low, and the expected prevalence of clonal individuals was lacking. The population dynamics of all three species within the Balkans was complex and distinct, and was characterized by a past admixture of individuals from discrete populations of the same species and interspecific hybridisation not only between V. myrtillus and V. vitis-idaea but also between V. uliginosum and V. vitis-idaea, the latter not being reported to date. Conservation measures suitable for preservation of presumably genetically distinct portions of the Balkans’ gene pools of studied species have been suggested, while the utility of interspecific hybrids in breeding programs and/ or in food/pharmaceutical industry is yet to be assessed. 

• Bjedov, University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia E-mail: ivana.bjedov@sfb.bg.ac.rs
• Obratov–Petković, University of Belgrade, Faculty of Forestry, Kneza Višeslava 1, 11000 Belgrade, Serbia E-mail: dragica.obratov-petkovic@sfb.bg.ac.rs
• Mišić, University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia E-mail: dmisic@ibiss.bg.ac.rs
• Šiler, University of Belgrade, Institute for Biological Research “Siniša Stanković”, Boulevard Despota Stefana 142, 11000 Belgrade, Serbia E-mail: branislav.siler@ibiss.bg.ac.rs
• Aleksic, University of Belgrade, Institute of Molecular Genetics and Genetic Engineering, Vojvode Stepe 444a, P.O. Box 23, 11010 Belgrade, Serbia E-mail: aleksic_jelena@yahoo.com.au

• Vakkari, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pekka.vakkari@metla.fi
• Rusanen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mr@nn.fi
• Kärkkäinen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: kk@nn.fi

• Avtzis, Aristotle University of Thessaloniki, Laboratory of Forest Genetics and Tree Breeding, Thessaloniki, Greece E-mail: dimitrios.avtzis@gmail.com
• Aravanopoulos, Aristotle University of Thessaloniki, Laboratory of Forest Genetics and Tree Breeding, Thessaloniki, Greece E-mail: FAA@nn.fi