The Effect of Manganese and Foliar Application of Salicylic Acid on Osmotic Regulators, Water Relations and Chemical Composition of Pistachio Seedlings in Saline Conditions

In order to investigate the effects of manganese and salicylic acid on chemical composition, osmotic regulators and water relations of pistachio seedlings (Pistacia vera L. cv. Badami Zarand) under saline conditions, a factorial experiment was carried out in a completely randomized design with three replications under greenhouse condition. Treatments consisted of manganese with concentrations of 0, 10 and 20 Mn2 kg-1 soil as MnSO4 ,H2O, and foliar application of salicylic acid hormone at three times with concentrations 0f 0, 0/5 and 1 mM and three levels of salinity (0, 1200 and 2400 mg NaCl kg-1 soil) that at the end of the experiment created average salinity of 2.9, 7.8 and 16.1 dSm-1, respectively. The results showed that the salinity decreased the leaf relative water content and increased the electrolyte leakage, but the combined application of the manganese and salicylic acid increased the leaf relative water content 46 percent and decreasedtheelectrolyte leakage. Salinity stress decreased the shoot Fe, Zn and Mn concentrations, but the combined application of 20 mg Mn2 and 1 mM salicylic acid increased the concentration of these elements by 26, 89 and 80 percent compared to control, respectively. The concentration of proline and soluble sugars increased with increasing the salinity and also the combined application of manganese and salicylic acid increased the concentration of these parameters by 100 and 88 percent, respectively. According to the results of this experiment, it was concluded that the combined application of manganese and salicylic acid in saline conditions through improving the physiological parameters and also increasing the micronutrients concentration, improved the pistachio plant ability against the salinity stress.