Effect of Salicylic Acid and Calcium on Chilling Resistance of Pistachios Seedlings, cv. Kaleghochi

In order to investigate the effects of salicylic acid and calcium on resistance chilling of pistachio seedlings, cv. Kale-Quchi, a factorial greenhouse experiment was carried out in a completely randomized design with three replications. Treatments consisted ofwere salicylic acid (0, 0.75 and 1.5 mM), calcium (0, 3 and 6 per thousand) and temperature (0, -2 and -4 °C). The results showed that, leaf electrolyte leakage percentage increased with decreasing temperature to -4 °C, but combined application of salicylic acid (1.5 mM) and calcium (6 per thousand) decreased this important indicator of chilling by 47 percent compared to control in this temperature. Also, with decreasing temperature (from 0 to -4 °C), the phenolic compounds, and soluble sugars and proline concentration incresed 44 and, 31 and 100 percent respectively and proline concentration more than two folds increaded compared to control seedlings. Also, the results of this experiment showed that the chlorophyll fluorescence index, total chlorophyll, carotenoids, soluble proteins and starch content decreased with decreasing temperature, but with combined application of 1.5 mM salicylic acid and treatment ofcalcium (6 per thousand) calcium, the amount of these parameters increased these parameters compared to control. So that the content of total chlorophyll, carotenoids, protein and starch increased compared to control at 4 °C by 87, 49, 25 and 99 percent, respectively compared to control and protected pistachio seedlings against chilling. Based on the results of this study, in chilling conditions, the combined application of salicylic acid and calcium, by improving the photosynthetic parameters and increasing osmotic regulators, decreased detrimental effects of chilling of pistachio seedlings. in chilling conditions.