Salt Tolerance of 22 Pomegranate Cultivars

Punica granatum (pomegranate) is an attractive fruit and ornamental shrub with orange-red flowers and colorful fruits. Interest in growing pomegranate has increased recently due to high levels of antioxidants in its fruits and well adaptation to hot and dry summer and moderately alkaline soil. A greenhouse experiment was conducted to screen 22 pomegranate cultivars for salt tolerance. Rooted hardwood cuttings were grown in CP512 treepots for three months and then pruned to 30 cm high. Pruned plants were irrigated once a week with saline solution at electrical conductivity (EC) of 10.0 dS·m^-1 for four weeks and subsequently with saline solution at EC 15.0 dS·m^-1 for another three weeks. Another group of pruned plants were watered with nutrient solution (no addition of salts) at EC of 1.3 dS·m^-1 as control. No visually foliar salt damage (leaf edge burn, necrosis, or discoloration) was observed during the period of the experiment regardless of cultivars. However, salt treatment significantly reduced the length of new shoots by 25% and dry weight of new shoots by 32% on average for all cultivars with large variations among cultivars. These results indicated that all pomegranate cultivars are moderately tolerant to the tested salinity level. A hierarchical cluster analysis using multivariate parameters (the length of new shoots, plant height, and dry weights of new leaves, new branches, and total new shoots) was conducted and the 22 pomegranate cultivars were classified into two groups. The group consisting of ‘AI’, ‘Deanda’, ‘Kazake’, ‘Russian 8’, ‘Apseronski’, ‘Purple Heart’, ‘CV’, ‘Chiva’, ‘Kunduzski’, ‘LC1’, ‘ML’, ‘Salavatski’, ‘Spanish Sweet’, ‘Wonderful’ was more salt tolerant than the group including ‘Al-sirin-nar’, ‘Kandahar’, ‘Surh Anor’, ‘Early Wonderful’, ‘Angel Red’, ‘Ben I’, ‘Utah Sweet’, and ‘Mollar’.