1. Laboratory of Plant Productivity and Environmental Stress, Faculty of Sciences of Tunis, University of El Manar, Tunis, Tunisia;
2. Unit of Plant Ecology, Faculty of Sciences of Tunis, University of El Manar, Tunis, Tunisia;
3. Laboratory of Pastoral Ecosystems and Promotion of Spontaneous Plants and Associated Micro-organisms, Institute of Arid Land, Medenine University of Gabes, Gabes, Tunisia;
4. Higher Institute of Arts and Crafts of Tataouine, University of Gabes, Zerig–Gabes, Tunisia