عنوان مقاله [English]
Background and Objectives: Pomegranate (Punica granatum L.) is an economically important commercial fruit plant species belonging to family Punicaceae. Pomegranate has been widely cultivated in arid and semi-arid regions of Iran, areas frequently affected by high salinity. In recent years, nearly 7% of the global cultivated lands are affected by salinity, and soil salinization aggravating has been a greater threat to healthy and sustainabledevelopment of agriculture all over the world. Therefore, the study aimed to determine the effects of salt stress on physiological and biochemical characteristics in pomegranate cuttings, in order to better understand the salt resistance of pomegranate and offer a reference for pomegranate cultivation on saline lands. Materials and Methods: A pot experiment was conducted during a nine-months period in order to evaluate and compare the salinity tolerance of three Iranian cultivar of commercial pomegranate in years 2017-2018. Experiment was arranged in a factorial based on completely randomized design with two factors included water salinity in 5 levels of 1, 3, 5, 7 and 9 dSm-1 and three ornamental pomegranate genotypes (‘Shishehcap Ferdos’, ‘Malas saveh’ and ‘Malas Yazdi’) in 4 replications and generally with 60 pots. In the end of the experiment the vegetative yield and fresh and dry weight of leaves, ion leakage, relative water content and chlorophyll a, b and total were also measured. In addition, leaves were analyzed for elements such as Na+, K+, Cl– and Na/K ratio. Results: Results showed that cultivar and salinity level were affected on morphological, physiological characteristics and concentration of nutritional elements. In all studied cultivars, with increasing of salinity levels in all of three investigated cultivars, growth characteristics, relative water content of leaves and chlorophyll significantly decreased and percentage of leaf necrosis, falldown and ion leakage, significantly increased. Also with increasing of salinity levels Na+, Cl- and Na+/Cl- significantly increased. In the highest level of salinity (9 dS.m-1) the maximum growth characteristics, fresh and dry weight of leaves, green leaves, relative water content of leaves, chlorophyll and potassium and the lowest percentage of leaf necrosis, ion leakage, Na+, Cl- and Na+/Cl- were obtained in cultivar of ‘Malas Yazdi’. Discussion: Generally, among investigated cultivars, ‘Malas Yazdi’ and ‘Malas Saveh’ were the most tolerant and the lowest one, respectively. Our study showed that the adverse effects on physiological and morphological indexes aggravated over stress time. We inferred that it was one of mechanisms for pomegranate alleviating the detrimental effects of salt stress. This study would provide a theoretical basis for the cultivation and utilization of pomegranate plants on saline soil.