Salt Tolerance and Cation Interaction in Alkali Sacaton at Germination

Salt tolerance and cation interaction in alkali sacaton (Sporobolus airoides Torr.) was studied during the germination stage. Germination was inhibited at a concentration of 275 meq/liter of sodium chloride. Mannitol and other salts at iso-osmotic pressure restricted germination in the following decreasing order: MgCl2, KCl, CaCl2, NaCl, and mannitol. Inhibitory effects of magnesium on germination were partially counteracted by calcium and sodium. Greater recovery in germination was noted by addition of calcium than sodium in seeds previously treated with a high concentration of magnesium chloride. The role of sodium and calcium in counteracting magnesium effects has been discussed. It is also concluded that specific effects of salts are more important than osmotic effects on the seed germination of this species.