1. Regional Research Center for the Improvement of Crops Adaptation to Drought; CERAAS-ISRA; P.O. Box 3320 Thies-Escale Thies Senegal
2. Dep. of Biology and Ecology; Univ. of Ouagadougou; 03 P.O. Box 7021 Ouagadougou 03 Burkina Faso
3. Senegalese Institute of Agricultural Research; CNRA-ISRA; P.O. Box 53 Bambey Senegal
4. Dep. of Botany and Plant Sciences; Univ. of California; Riverside CA 92521-0124
5. Japan International Research Center for Agricultural Sciences (JIRCAS) and International Institute of Tropical Agriculture (IITA); PMB 5320 Ibadan Nigeria