Physiological enhancement of medicinal pumpkin seeds (Cucurbita pepo. var. styriaca) with different priming methods

In order to evaluate the effects of priming materials and duration of priming on the seed physiological enhancement and biochemical traits of germination in pumpkin seeds a factorial experiment was conducted based on a completely randomized design with three replications at the University of Mohaghegh Ardabili. Treatments were priming with water, NaCl (3%), gibberellic acid (20 mg L^-1), and ascorbic acid (20 ppm) for 8, 16, and 24 hours. Seed mass as a control for comparison of different pretreatment methods was measured. Results showed that priming treatments except gibberellin application, caused an increase in radicle length. Increase in priming duration increased the plumule length of seedlings. With increasing duration of priming, radicle length also increased except for seeds primed with NaCl. Seedlings from primed seeds with gibberellin had the highest dry weight (1.08 g) when compared to other priming treatments and control. Percentage and germination rate in the seeds primed with water, gibberellic acid, and ascorbic acid increased with increasing duration of priming and it was observed that the rate of increase was even higher in ascorbic acid treatment. Superoxide dismutase, catalase, and peroxidase in sodium chloride and gibberellic acid treatments had the highest and lowest activity, respectively. The activity of these enzymes had upward trend except in halo-priming, and hormone-priming with gibberellin for 24 h was the best treatment considering enzyme activity.