Responses of pomegranate (Punica granatum L.) drought- tolerant rootstocks to the salinity of irrigation water

Purpose: Pomegranate is an important crop in Iran. However, soil and water salinity in pomegranate growing areas of Iran is one of the most important abiotic stresses resulting in economically significant losses. The most effective way to deal with salinity is to develop salinity-tolerant rootstocks and cultivars and use them in areas with saline soil and water. Research method: The experiment was conducted as a factorial based on a completely randomized design, where three rootstocks (‘Daneshgah 8’, ‘Daneshgah 13’, and ‘Daneshgah 32’) and five salinity levels (irrigation water as a control treatment, and concentrations of 25, 50, 75 and 100 mM sodium chloride) were the factors. Salinity treatments were applied in June, July, and August on three-year plants. By the end of the study, some morphological, physiological, and biochemical traits were recorded. Findings: Under salinity stress conditions, pomegranate rootstocks showed apparent differences in measured traits. Among the evaluated rootstocks, ‘Daneshgah 13’ exhibited good tolerance to salinity stress due to the smaller reductions in leaf relative water content, chlorophyll content, plant height, shoot number, fresh and dry weight, as well as lower values of ion leakage, and necrotic and fallen leaves. Research limitations: By measuring some other physiochemical traits such as antioxidant enzymes and proline contents, the response of pomegranate drought-tolerant rootstocks to the salinity can be more clearly interpreted. Originality/Value: Therefore, ‘Daneshgah 13’ can be used as appropriate genetic resources in breeding programs for tolerance to salinity.