干旱区生态环境知识资源中心

This work has focused on the study of germination characteristics of seeds of Acacia tortilis (Forsk.) Hayne subsp. raddiana (Savi) Brenan, a species native of Tunisia, and of two introduced species : Acacia salicina Lindl. and Acacia ampliceps Maslin, reforested in arid zones of Tunisia. Germination was followed under conditions of water and salt stresses. Pre-treatments designed to remove integumentary inhibitions were applied to seeds. The germination behaviour of acacias in osmotic stress conditions showed a treatment effect, concentration of PEG 6000, highly significant on germination rate and mean time of germination. We found that these species did not tolerate drought and we observed a complete inhibition of germination at -0.8 MPa. The study of the effect of salt stress on germination showed a better tolerance of Acacia tortilis (Forsk.) Hayne subsp. raddiana (Savi) Brenan to salinity than the other two species as it germinated at high salt concentrations. Indeed, at 18 g/l the germination rate reached 32 %. We didn’t find any relationship between seed germinative properties and ecology of the adult plant.