Stimulate drought stress tolerance by polyethylene glycol in wheat seedling by various concentrations of ascorbic acid

A lab experiment was carried out to investigate the role of ascorbic acid on wheat seedling drought stress induced by polyethylene glycol (PEG-6000) on some physiological traits and enzyme activity. The Wheat seeds were activated using ascorbic acid in four concentrations: 0, 25, 50 and 100 mg L-1. The germination medium was treated with PEG-6000 compound to achieve 0, -0.4, -0.8 and -1.2 bar tensions. The study's findings showed that the 50 mg L-1 ascorbic acid concentration provided the highest rates of wheat seed germination percentage; 99.2 %, root length; 12.30 cm, shoot length; 11.64 cm and relative water accounting for 84.75 %. Additionally, catalase and peroxidase enzymes increased most at the same ascorbic acid concentration. Also, the same concentration (50 mg L-1) improved the electrical conductivity of wheat seedling cells by recording the lowest rate of 3.53 dS/m. On the other hand, showed the lowest rates at high stress of PEG-6000 -1.2 bar when recording a germination percentage of 52.58 %, root length; 5.24 cm, shoot length; 5.79 cm and relative water content reached 56.32 %. In addition to causing the highest rise in enzymatic antioxidants for catalase and peroxidase, the same stress also had the highest rate of electrical conductivity, reaching 11.49 dS/m.