In vitro screening for salinity tolerance in pomegranate (Punica granatum L.) by morphological and molecular characterization

Salinity represents a threating challenge for agricultural systems and food production worldwide. Therefore, selection for crop varieties more tolerant to salinity is a global concern. In vitro screening protocols for abiotic stresses, especially with woody plants, solve critical issues of hard-to-perform feld or greenhouse evaluation approaches. In this study, six genotypes of the most cultivated pomegranate varieties in Egypt were selected for in vitro salinity tolerance evaluation. Morphological traits showed a signifcant variation among pomegranate cultivars except for water content. Also, the interaction between cultivars and treatments was highly signifcant in all traits except for shoot number and water content. Based on the salinity susceptibility index, both 'Nab Elgamal' and 'Manfalouty' showed salinity tolerance. Meanwhile, 'Wonderful' and 'Araby' showed intermediate responses and were considered moderate tolerant. 'Hegazy' and 'Wardi' were the most afected cultivars, refecting their susceptibility to salinity. Molecular markers as inter-simple sequence repeat and start codon targeted (SCoT) polymorphism showed an apparent variation among cultivars under salt stress. SCoT was more potent in exposing higher values of polymorphism and other diversity measures. Moreover, SCoT-based dendrogram was highly like that based on morphological data, in which both dendrograms grouped cultivars according to their salt tolerance. The work provides a reliable method for salinity screening in pomegranates. This might help accelerating breeding programs for woody plant species by selecting superior genotypes tolerant to salinity stress in rapid and efcient way.