干旱区生态环境知识资源中心

Acacia ehrenbergiana Hayne and Acacia seyal Del. are two desert trees of the Algerian Sahara that for a long time were confused. These two species present high potentials for desert areas rehabilitation therefore for successful seed germination and establishment three pre-germination treatments (manual scarification, boiling water and concentrated sulphuric acid) were used to overcome seeds dormancy. Once the optimal conditions are determined, we examined the effects of two abiotic stresses (salinity and water deficiency) on their seeds germination using eight levels of salinity (0, 50, 100, 150, 200, 250, 300 and 350mM of NaCl) and six concentrations of PEG(6000) (0, -2, -4, -6, -8 and -10 bars) on Acacia ehrenbergiana Hayne and Acacia seyal Del. Germination rate and mean germination time were calculated and data were subjected to analysis of variance (ANOVA) followed by Newman-Keuls test. Our results show that manual scarification and sulphuric acid had significant effects on the seeds germination of Acacia ehrenbergiana Hayne meanwhile, only sulphuric acid enhanced Acacia seyal Del. seeds germination. Under salt and water stresses, the germination rate and mean germination time of Acacia ehrenbergiana Hayne were less affected than those of Acacia seyal Del. Therefore manual scarification and sulphuric acid treatments could be applied and adopted at laboratory level or even at nurseries to raise plants germination and plantations establishment for desert areas rehabilitation. Thus, Acacia ehrenbergiana Hayne seems to be more suitable for massive propagation as it demonstrates resilience when facing harsh abiotic stresses (salt and water stresses).