M. ABID1, E. MANSOUR1, A. BEN KHALED1, Kh. D. BACHAR1, L. BEN YAHYA1 and A. FERCHICHI2
1 Institute of Arid Lands, 4119 Medenine, Tunisia
2 National Institute of Agronomy – Tunis,1082 Mahraj, Tunisia
ABID, M., E. MANSOUR, A. BEN KHALED, Kh. D. BACHAR, L. BEN YAHYA and A. FERCHICHI, 2016. Induced osmotic adjustment in alfalfa plants confers tolerance to water stress. Bulg. J. Agric. Sci., 22: 415–425
South Tunisian oases are characterized by arid environment in which drought is a major limiting factor for growth and crop production. In these conditions, understanding plant adaptation is required in order to preserve such regions from degradation. Four levels of water stress were applied to evaluate the effect of drought in three Medicago sativa populations (Chenini, Gannouch and Tebelbou): 25%; 50%; 75% and 100% of fi eld capacity. Under water defi cit conditions, leaves and roots exhibited a higher increase in proline, total soluble sugars, amino acids and potassium. A decrease in dry matter production was observed especially in alfalfa leaves. Chenini population showed the highest increase in different solutes, in contrary Tebelbou seems to be the most affected by drought as it showed lowest values. A close relationship was observed between proline and several osmolytes indicating that it is an important indicator of drought stress tolerance in alfalfa plants.