EVALUATION OF THE EFFECT OF BIOLOGICAL ELICITORS ON THE RESISTANCE TO SALINITY STRESS IN THE DATE PALM (Phoenix dactylifera L., cv. Stameran)

To evaluate the effect of biological elicitors, including fungi and bacteria, on resistance to salinity stress in the date palms. The experiment was conducted in a factorial, completely randomized design (CRD) with two factors, i.e., salinity with three levels (0, 150, and 300 mM) and the fungal and bacterial elicitors at five levels. The elicitors treatments were comprised of fungal consortium (BFC), fungal elicitor at 1,000 ppm concentration (EL1), fungal elicitor at 2,000 ppm concentration (EL2), and the bacteria (BS), Bacillus safensis, and Bacillus pumilus. The results showed that the lowest hydrogen peroxide content (278 mu mol/g) was found in the seedling treated with elicitor of B. safensis at the zero salinity level. Catalase enzyme activity was higher in plants treated with fungal elicitor at 2,000 ppm concentration and the zero salinity level, B. safensis at the 150 mM salinity level, and fungal consortium at the 300 mM salinity level. The hydrogen peroxide content in the plant decreased as the activity of PAL and PPO enzymes increased. Applying an elicitor may reduce the effects of salinity stress in the date palm, but the stress level could determine the impact of each elicitor.