1. National Fund for Scientific Research (F.R.S.-FNRS), Rue d’Egmont, 5, 1000 Brussels, Belgium.
2. Gembloux Agro-Bio Tech, University of Liège, Passage des Déportés, 2, 5030 Gembloux, Belgium.
3. Walloon Association of Breeders, Rue des Champs Elysées, 4, 5590 Ciney, Belgium.