Jan-Peter George1, Heino Konrad1, Eric Collin1, Jean Thevenet1, Dalibor Ballian1, Marilena Idzojtic1, Urs Kamm1, Peter Zhelev1, Thomas Geburek2. 1. BFW, Federal Research and Training Center for Forests, Natural Hazards and Landscape, Department of Forest Genetics, Hauptstraße 7, 1140 Vienna, Austria, IRSTEA, Institut National de Recherche en Sciences et Technologies pour l'Environnment et l'Agriculture, Domaine des Barres, 45290 Nogent sur vernisson, France, INRA, Unite experimentale Entomologie et Foret Mediterraneenne, Domaine Saint Paul-Site Agroparc, CS 40509, 84914 Avignon Cedex 9, France, Faculty of Forestry, University of Sarajevo, Zagrebacka 20, 71000 Sarajevo, Bosnia and Herzegovina, Faculty of Forestry, University of Zagreb, Svetosimunska 25, 1000 Zagreb, Croatia, Swiss Federal Research Institute WSL, Biodiversity and Conservation, Ecological Genetics, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland and University of Forestry, 10 Kliment Ohridski blvd., 1756 Sofia, Bulgaria. 2. BFW, Federal Research and Training Center for Forests, Natural Hazards and Landscape, Department of Forest Genetics, Hauptstraße 7, 1140 Vienna, Austria, IRSTEA, Institut National de Recherche en Sciences et Technologies pour l'Environnment et l'Agriculture, Domaine des Barres, 45290 Nogent sur vernisson, France, INRA, Unite experimentale Entomologie et Foret Mediterraneenne, Domaine Saint Paul-Site Agroparc, CS 40509, 84914 Avignon Cedex 9, France, Faculty of Forestry, University of Sarajevo, Zagrebacka 20, 71000 Sarajevo, Bosnia and Herzegovina, Faculty of Forestry, University of Zagreb, Svetosimunska 25, 1000 Zagreb, Croatia, Swiss Federal Research Institute WSL, Biodiversity and Conservation, Ecological Genetics, Zürcherstrasse 111, 8903 Birmensdorf, Switzerland and University of Forestry, 10 Kliment Ohridski blvd., 1756 Sofia, Bulgaria thomas.geburek@bfw.gv.at.
Abstract
BACKGROUND AND AIMS: Sorbus domestica (Rosaceae) is one of the rarest deciduous tree species in Europe and is characterized by a scattered distribution. To date, no large-scale geographic studies on population genetics have been carried out. Therefore, the aims of this study were to infer levels of molecular diversity across the major part of the European distribution of S. domestica and to determine its population differentiation and structure. In addition, spatial genetic structure was examined together with the patterns of historic and recent gene flow between two adjacent populations. METHODS: Leaf or cambium samples were collected from 17 populations covering major parts of the European native range from north-west France to south-east Bulgaria. Seven nuclear microsatellites and one chloroplast minisatellite were examined and analysed using a variety of methods. KEY RESULTS: Allelic richness was unexpectedly high for both markers within populations (mean per locus: 3·868 for nSSR and 1·647 for chloroplast minisatellite). Moreover, there was no evidence of inbreeding (mean Fis = -0·047). The Italian Peninsula was characterized as a geographic region with comparatively high genetic diversity for both genomes. Overall population differentiation was moderate (FST = 0·138) and it was clear that populations formed three groups in Europe, namely France, Mediterranean/Balkan and Austria. Historic gene flow between two local Austrian populations was high and asymmetric, while recent gene flow seemed to be disrupted. CONCLUSIONS: It is concluded that molecular mechanisms such as self-incompatibility and high gene flow distances are responsible for the observed level of allelic richness as well as for population differentiation. However, human influence could have contributed to the present genetic pattern, especially in the Mediterranean region. Comparison of historic and recent gene flow may mirror the progress of habitat fragmentation in eastern Austria.
BACKGROUND AND AIMS: Sorbus domestica (Rosaceae) is one of the rarest deciduous tree species in Europe and is characterized by a scattered distribution. To date, no large-scale geographic studies on population genetics have been carried out. Therefore, the aims of this study were to infer levels of molecular diversity across the major part of the European distribution of S. domestica and to determine its population differentiation and structure. In addition, spatial genetic structure was examined together with the patterns of historic and recent gene flow between two adjacent populations. METHODS: Leaf or cambium samples were collected from 17 populations covering major parts of the European native range from north-west France to south-east Bulgaria. Seven nuclear microsatellites and one chloroplast minisatellite were examined and analysed using a variety of methods. KEY RESULTS: Allelic richness was unexpectedly high for both markers within populations (mean per locus: 3·868 for nSSR and 1·647 for chloroplast minisatellite). Moreover, there was no evidence of inbreeding (mean Fis = -0·047). The Italian Peninsula was characterized as a geographic region with comparatively high genetic diversity for both genomes. Overall population differentiation was moderate (FST = 0·138) and it was clear that populations formed three groups in Europe, namely France, Mediterranean/Balkan and Austria. Historic gene flow between two local Austrian populations was high and asymmetric, while recent gene flow seemed to be disrupted. CONCLUSIONS: It is concluded that molecular mechanisms such as self-incompatibility and high gene flow distances are responsible for the observed level of allelic richness as well as for population differentiation. However, human influence could have contributed to the present genetic pattern, especially in the Mediterranean region. Comparison of historic and recent gene flow may mirror the progress of habitat fragmentation in eastern Austria.
Authors: Rémy J Petit; Itziar Aguinagalde; Jacques-Louis de Beaulieu; Christiane Bittkau; Simon Brewer; Rachid Cheddadi; Richard Ennos; Silvia Fineschi; Delphine Grivet; Martin Lascoux; Aparajita Mohanty; Gerhard Müller-Starck; Brigitte Demesure-Musch; Anna Palmé; Juan Pedro Martín; Sarah Rendell; Giovanni G Vendramin Journal: Science Date: 2003-06-06 Impact factor: 47.728