effect of superabsorbent polymer aquasorb on chlorophyll, antioxidant enzymes and some growth characteristics of acacia victoriae seedlings under drought stress

to investigate the effect of droughtstress on chlorophyll content, enzymatic responses and some growth characteristics of acacia victoriae seedlings and the effect of super-absorbent polymers (sap) in reducing drought stress, a split plot experiment based on the completely randomized design was conducted. the treatments included four levels of drought stress (15, 30, 60 and 100% of field capacity) and four levels of sap (0, 0.2, 0.4 and 0.6% weight percentages). the results of anova showed a significant effect of drought stress on all growth characters, chlorophyll content and catalase and peroxidase enzymes activity, while the sap didn't show any significant effect on the weight and areas of the leaves. the interaction effect between drought stress and sap on the weight, number of leaves, proportion of root dry weight to aerial organs, chlorophyll and peroxidase enzyme activity was also significant. the effect of drought stress on reducing the number of the leaves, leaf area, length, volume and surface of roots and also increasing the root dry weight to aerial organs dry weight ratio, amount of chlorophyll and activity of antioxidant enzymes was significant. the different levels of sap could absorb and hold water and consequently reduce the effect of drought stress and improve the growth characteristics and reduce the activity of catalase and peroxidase enzymes.