Effect of Different Priming Treatments and Different Irrigation Intervals on Biochemical Characteristics of Two Bread Wheat Cultivars (Triticumaestivum)

Seed priming is a method in which the water absorption in a controlled manner is allowed to seed before plantinguntil the first germination activities begin, but without allowing radicle emergence.In order to investigate the possibility for increasing wheat tolerance to water tension by seed priming technique, the present experiments was performed as factorial and as a randomized complete blocks design with three replications in Greenhouse Agriculture Faculty of Shiraz University. The experimental treatments included two cultivars of wheat (Azar2 and Shiraz), four levels of priming (non-priming, osmo-priming and phosphopriming and hydropriming) and four levels of water tension (intervals of irrigation 2 (non-tension), 4, 6 and 8 days). For both the two wheat cultivars, the highest tension level (8 days irrigation intervals) caused increasing in catalase amount activity at the probable level of 5 percentage. Increasing in water tension leads to increasing in the amount of catalase at the probable level of 5 percentage. By increasing the water tension, the amount of ascorbic peroxidase and peroxidase enzymes increased significantly. Types of different priming treatments did not result in significant difference at the probable level of 5 percentage in catalase enzyme activity. In this research, Azar2 cultivar compared to Shiraz cultivar was known as the more resistant to water tension. Peroxidase and ascorbic peroxidase enzymes activity is influenced by osmopriming treatment increased by 01/10 and 21.4 percentage respectively, compared to the no-priming. The maximum proline content (13l/68 micromole per gram fresh weight(was related to osmopriming treatment in Azar2 cultivar under the highest tension levels (8 days irrigation intervals). According to the results of this research, it appears that osmopriming treatment by effect on antioxidant defense system of plant, would be involved in the process of increasing drought resistance in wheat seedlings.