Department of Botany;
Faculty of Science;
University of Douala;
Douala 24157;
Cameroon;
Department of Botany;
Faculty of Science;
University of Yaounde L Yaounde 812;
Cameroon;
UMR;
INRA-UCBN;
Ecophysiology Plant;
Agronomy and Nutrition NCS;
Institut of Fundamental and Apply Biology;
University ofCaen;
Caen Cedex F-14032;
France;