Evaluation of physiological and biochemical responses of some Iranian commercial pomegranate cultivars to salinity stress

Water and soil salinity are one of the most important restrictions on the growth and production of fruit trees. Control of this phenomenon can be one of the factors to managing the production and guarantee the production sustainability and optimal use of land and water. Therefore, in order to investigate the effect of salinity stress on the physiological and biochemical properties of some Iranian commercial pomegranate cultivars and identification of salinity tolerant cultivars, a greenhouse research conducted at the Faculty of Agriculture of Lorestan University in 2015. The Factorial experiment based on randomized complete block design with five levels of salinity (0, 25, 50, 75 and 100 mM NaCl) and six pomegranate cultivars include Malas Dane Ghermez Esfahan, Malas Yazdi, Shirin Shahvar, Meykhosh Yazd, Malas Saveh and Malas Yousofkhani and with three replications. After three months of applying salt stress, some physiological and biochemical properties of the plants were examined and measured. The results showed that in control treatment, compared to 100 mM NaCl treatment with increasing salinity, chlorophyll a (42%), chlorophyll b (40%), total chlorophyll (42%) and total carotenoids (65%) decreased significantly and Electrolyte leakage rate (27%), malondialdehyde (94%), and peroxidase (506%), catalase (478%), and ascorbate peroxidase (366%) enzymes increased. In addition, comparison of data meanings showed that there was a significant difference between cultivars in measured factors. The results showed that, in salt stress conditions, Malas Yousofkhani cultivar was superior to salinity tolerance in most traits, and this genotype was more tolerant to salinity than other evaluated cultivars.