Pre-sowing seed invigoration methods are promising approach to alleviate the adverse effects of abiotic stresses on seed germination and early seedling establishment. The current study was conducted to evaluate the impacts of preplant soaking of wheat (cv. Sardari) seeds in different concentration of salicylic acid and ascorbic acid (30, 60, 90, 120, 150, and 180 ppm) on seedling early growth and antioxidant activity. Results showed that the highest germination percentage were recorded for seed treated with dilute solutions of acid salicylic (30 and 60 ppm) and intermediate concentration of acid ascorbic (90 ppm). The mentioned concentration increased the germination rate by 80%, root length by 7 cm and shoot length by 5 cm when compared with control. Hormonal seed treatments through 60 and 90 ppm ascorbic acid induced an increased seedling dry weight. However, the highest seedling vigor was achieved by low concentration of salicylic acid. Hormonal priming with acid ascorbic had a more stimulating and increasing effect on the activity of the superoxide ismutase enzyme compared to salicylic acid. The highest activity of catalase and guaiacol peroxidase were recorded for seed primed with 90 ppm salicylic acid and 60 ppm ascorbic acid, respectively. It is concluded that hormonal seed treatments has increased seedling early growth and antioxidant activity and the best performance was related to 30 ppm salicylic acid and 60 and 90 ppm ascorbic acid. The results of the present study elucidated that hormonal seed treatments as a useful, efficient and easy invigorating approach should be seriously considered in wheat fields.
