The Effect of Water Stress on Some Physiological and Biochemical Indices of Pomegranate cv. ‘Wonderful’

Drought stress is one of the limiting factors of agriculture in many parts of the world, especially Iran. Understanding the mechanism behind drought stress’ effect on physiological and biochemical processes of genotypes is very useful for selecting and breeding genotypes compatible with Iranian conditions. For this purpose, the present study has been conducted in 2018-2019 in the Biotechnology Research Institute of Shiraz University to investigate the effect of drought stress on physiological and biochemical characteristics of both years’ old pomegranate seedlings of Wonderful cultivar in greenhouse conditions. Irrigation has been carried out at four levels of 100% (control), 75%, 55%, and 35% of field capacity for 50 days. The experiment is based on a completely randomized design with three replications. The results show that drought stress has significantly increased carotenoids, flavonoids, malondialdehyde, and proline. The relative leaf water content, cell membrane stability and anthocyanins has decreased, though there has been no significant difference in chlorophyll and glycine betaine levels between drought treatments. Also, the hydrogen peroxide (81%) and activity of superoxide dismutase (480%), catalase (96%), and ascorbate peroxidase (96%) in 35% of field capacity significantly has increased. According to the results of this study, especially the increase in proline and antioxidant enzymes under drought stress, tolerance mechanisms in pomegranate cultivar Wonderful can be associated with active osmotic regulation and active enzymatic antioxidant system.