1. Institute of Agricultural Research for Development (IRAD), Njombe Multipurpose Station, Yaoundé P.O. Box 13, Cameroon
2. 631 Avenue du Comté de Nice, 34080 Montpellier, France
3. Physiology and Plant Improvement Unit, Laboratory of Biotechnology, Department of Plant Biology, Faculty of Sciences, University of Yaoundé I, Yaoundé P.O. Box 812, Cameroon
4. 4 avenue des chasseurs 34130 Saint Aunès, France