1. Department of Biology; University of Fribourg; Chemin du Musée 10 CH-1700 Fribourg Switzerland
2. Applied Forest Genetics; Bavarian Office for Forest Seeding and Planting; Forstamtsplatz 1 83317 Teisendorf Germany
3. Department of Genetics; Austrian Federal Research and Training Centre for Forests; Natural Hazards and Landscape; Seckendorff-Gudent-Weg 8 A-1130 Vienna Austria
4. Department of Botany and Biodiversity Research; University of Vienna; Rennweg 14 A-1030 Vienna Austria