Evaluation of Drought Tolerance of Some Native Pistachio Genotypes of Qazvin Province

In this study, 10 selected pistachio genotypes were affected by irrigation treatments. Irrigation treatments included two levels of full irrigation and withholding of irrigation for two weeks, which were applied on three months seedlings. After the stress period, all plants (control and under stress) were irrigated again to the field capacity and their moisture was maintained at the field capacity for two weeks and different parameters were measured. Under water stress conditions, the highest relative water content of leaves (60.29%) belonged to P9 genotype. The P3 genotype also had the lowest ion leakage (41.8%), the lowest malondialdehyde concentration (18.73 μmol/g fresh weight), the highest proline concentration (0.8683 μmol/g fresh weight), and the highest concentration of soluble sugars (12.03 mg/g fresh weight). Under water stress conditions, the lowest relative water content of leaves (54.32%), the highest ion leakage (58.84%), the highest concentration of malondialdehyde (27.19 μmol/g fresh weight), the lowest amount of proline (0.53 μmol/g fresh weight) and the lowest amount of soluble sugars (6.697 mg/g fresh weight) also belonged to P8 genotype. In terms of growth parameters, the results showed that P1, P3 and P9 genotypes under water stress treatments showed less reduction than the control compared to other genotypes. In general, the results showed that P3, and P9 genotypes tolerated drought better than other genotypes and the P8 genotype showed more sensitivity to drought.