Abstract
The date palm is a woody plant growing in different regions of the world. Two potential cultivars of the date palm (Ajwa and Mabroom) from Saudi Arabia were studied for their tolerance to salinity stress (0, 50, 100 and 150 mM NaCl). Salinity stress affected morphometric traits as well as biomass yield in both cultivars. The percent germination under different concentrations of NaCl was greater in the Ajwa compared to the Mabroom. The Ajwa cultivar showed enhanced activities of antioxidant enzymes (Catalase: CAT; superoxide dismutase: SOD and glutathione reductase; GR) than the Mabroom. Thiobarbituric acid reactive substance (TBARS) content increased in both cultivars compared to the control. The osmolytes level (proline) was increased whereas soluble protein was decreased in both cultivars. The leaf relative water content (LRWC) was decreased as compared to the control and greater reduction was seen in the Mabroom cultivar. Abscisic acid content was found to be higher in the Ajwa cultivar than that in the control plant and Mabroom. In conclusion, the Ajwa cultivar showed greater salinity tolerance compared to Mabroom which possible owing to the presence of tolerance genes in the genome.