1. INIA Forest Research Centre, Department of Forest Ecology and Genetics, Carretera A Coruña km 7·5, 28040 Madrid, Spain
2. INRA, Université de Bordeaux, UMR 1202 BIOGECO, 33610 Cestas, France
3. INRA, UMR1062 CBGP, 34988 Montferrier-sur-Lez, France
4. INRA, UMR 1334 AGAP, 34060 Montpellier, France
5. Faculty of Science and Technology, Free University of Bolzano, piazza Università 1, 39100 Bolzano, Italy
6. National Research Council, Institute of Biosciences and Bioresources, Via Madonna del Piano 10, 50019 Sesto Fiorentino (Florence), Italy
7. Centro de Investigaciones sobre Desertificación (CIDE-CSIC), 46113 Moncada (Valencia), Spain