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چکیده
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The physiological quality of seeds decreases during their storage under unfavourable conditions. These deteriorated seeds exhibit a poorer performance, especially under stress conditions. A factorial experiment was conducted to investigate the effects of H2O2 on the germination of aged pumpkin seeds under drought stress. Hydroprimed seeds and also the seeds pre-treated with 100, 200 and 400 µM H2O2 were exposed to drought (0, -0.2, -0.4, and -0.6 MPa applied using PEG). Under drought conditions, seeds primed with H2O2 showed improved germination percentages and rates, higher vigour index, greater plumule and radicle lengths, enhanced soluble sugars and protein contents, and more antioxidant enzymes activities e.g. catalase, ascorbate peroxidase and superoxide dismutase in comparison to untreated controls. However, mean germination time and malondialdehyde (MDA) content total soluble proteins decreased in primed seeds. Those primed with 100 µM H2O2 showed the highest germination rate, vigour index, soluble sugars, and total soluble protein by 93, 46, 76, and 51% respectively at a drought level of -0.6 MPa. H2O2 at 100 Μm applied to deteriorated total soluble proteins pumpkin seeds reduced of the negative effects of deterioration, especially under drought stress.
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