Volume 12, Numéro 2, Pages 3052-3062
Description of the subject: Acacia karroo is regarded as a promoting candidate to rehabilitate lands suffering different levels of environmental stresses (e.g., salinity and drought stress). Objective : We have conducted, therefore, a study on the germination behavior in seeds using two abiotic constraints: salt stress through using NaCl and Na2SO4 at different levels (90, 180, 270 and 360 mM) and water stress, as simulated by PEG6000, at different water potentials (-0.25, -0.5,-0.75 and –1 MPa). Methods : First, seed germination features were recorded through final percentage and germination rate. On the other hand, we appreciated the response of seedlings to different treatments by measuring the length of seedlings, fresh and dry weights, as well as the seedling vigor index. Results : Salt and water stress significantly affect germination as it was displayed through a steady decrease in seed emergence on increasing both stresses. Still, despite a high stress levels, A. karroo seeds successfully established and could germinate up to 360 mM NaCl (44%), 270 mM Na2SO4 (11%), and –1 MPa PEG (31%). Overall, this species seems to be tolerant to salt and drought stresses, albeit a reduction in seedling length, at the initial growth phases. Conclusion : The results on germination attributes and growth features, being the most sensible stage in plant life cycle, of A. karroo seeds and seedlings against the abiotic stresses is certainly useful to imbedding this multipurpose plant in reforestation projects and consequently spreading its distribution for a beneficial exploitation.
Acacia karroo ; growth ; germination ; salt stress ; water stress
Said Houari Amel