Effects of sodium chloride salinity on seed germination, and seedling root and shoot extension growth of four sorghum, Sorghum bicolor cultivars

Increased NaCl salinity, decreased the percentage number of seed that germinated and the seedling root and shoot extension of four sorghum cultivars. Transferral of seeds that had not germinated in various salt treatments to distilled water, only slightly increased the number of seeds that germinated. The decrease in seed germination and shoot/root extension was attributed largely to ionic toxicity than to osmotic factors. Root extension was found to be more sensitive to salinity stress than shoot extension in KAT/369, Seredo and KAT/487, but the opposite was the case in Serena. Based on the level of salinity that caused 50% reduction in seed germination, Seredo and KAT/487 were found to be more tolerant, while KAT/369 and Serena were more tolerant to NaCl salinity with respect to root/shoot extension.