Mana Mombeini - Department of Horticultural science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
Naser Alamzadeh Ansari - Department of Horticultural Science, Agriculture Faculty, Shahid-Chamran University, Ahvaz, Iran
Vahid Abdossi - Department of Horticultural science and Agronomy, Science and Research Branch, Islamic Azad University, Tehran, Iran
abdali Naseri - Department of Irrigation and Drainage, Water Science Engineering Faculty, Shahid-Chamran University, Ahvaz, Iran

Seed priming is one of the most important measures in propagation of plants by seed, which leads to increase of percentage and rate of germination. This study was conducted as a factorial arrangement in a completely randomised design on two farm cucumber cultivars (‘Impress’ and ‘Emperor’). Priming treatments were silicic acid (SA) and ascorbic acid (AsA) at three levels of ۵۰, ۱۰۰ and ۱۵۰ mg L-۱, pyridoxine at three levels of ۰.۰۲%, ۰.۰۴% and ۰.۰۶% and compound treatment (SA ۷۵ mg L-۱ + AsA ۷۵ mg L-۱ + pyridoxine ۰.۰۳%). There was a positive and significant correlation between the Catalase (CAT) enzyme activity in the radicle and plumule and Polyphenol oxidase (PPO) in the radicle and germination rate and percentage. In the ‘Impress’ cultivar, the highest CAT activity in the radical and plumule was observed after using of ۱۵۰ mg L-۱ AsA. The highest activity of Polyphenol oxidase (PPO) in the radical was detected after using of ۰.۰۴% pyridoxine. In the ‘Emperor’ cultivar, the highest CAT enzyme activity was detected in the radical and plumule, respectively by using of ۷۵ mg L-۱ AsA, ۷۵ mg L-۱ SA, and ۰.۰۳% pyridoxine. AsA (۵۰ mg L-۱) induced the highest activity of PPO enzyme in the radicle. Finally, to increase the antioxidant enzyme activity in cucumbers against unfavourable environmental conditions, our results confirmed the effectiveness of ۱۵۰ mg L-۱ AsA and ۰.۰۴% pyridoxine for the ‘Impress’ cultivar and the compound treatment and ۵۰ mg L-۱ AsA for the ‘Emparator’ cultivar.

Catalase, Ascorbic acid, Pyridoxine, Silicic acid, germination