1. Laboratory of Plant Physiology, Dep. of Biological Science; Higher Teachers’ Training College; Univ. of Yaounde I; Yaounde Cameroon
2. Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences; Key Laboratory of the Ministry of Agriculture for Germplasm Resources Conservation and Utilization of Cassava; Danzhou City Hainan Province China
3. Laboratory of Phytoprotection and Valorization of Plants Resources; Biotechnology Centre-Nkolbisson; Yaounde Cameroon
4. Genetic Resources and Biotechnology; Embrapa Brazil