Evaluation the effects of ascorbate and folic acid on improving some germination indicators of wheat (Triticum aestivume L.) under salt and drought stress

In order to evaluate the effect of ascorbic acid and folic acid on germination parameters under drought and salinity stress, two separate experiments was carried out in completely randomized factorial design with Azar2 Wheat cultivar. In this experiment, wheat seeds were pretreated for 16 hours with concentration of zero (control), 0.5 and 1 mM of ascorbic acid and 25 and 50 μM folic acid. Seeds were then dried at room temperature until the initial weight. To apply drought and salinity stress the solution of polyethylene glycol 6000 at 0 (control), -6 and -12 bar and sodium chloride at zero, 75 and 150 mM concentration were used, , respectively. Subsequently, petri dishes containing wheat seeds were kept at temperature of 24±1°C, 70% relative humidity and darkness condition for 8 days. After the mentioned time, germination percentage, germination rate, root and shoot length and seedling dry weight were measured. The results showed that seed treatment with vitamins, even in favorable conditions, with reduction of the loss of seed reserves, can help more allocation of seed reserves at formation of seedling structure, and cause to generate of stronger seedlings. Under drought and salinity stress conditions, seed treatment with ascorbic and folic acid, by creating appropriate conditions, can prevent damages caused by generate reactive oxygen species or prevent from their production, which the result of its, is the absent expression of oxidative stress on in seed germination. These factors result in increasing growth respiration rate and formation of stronger seedlings. Therefore, increasing the amount of mentioned vitamins in seeds can improve the metabolic function, especially in difficult environmental situations and contribute in better seedling establishment.