VARIETAL DIFFERENCES IN SODIUM UPTAKE IN BARLEY CULTIVARS EXPOSED TO SOIL-SALINITY OR SALT SPRAY

Barley varieties are known to differ in the extent of Na+ and Cl- accu mulation in leaves when grown in saline soil or hydroponic culture. In particular, the cv. Chevron accumulates more Na+ than the more salt-t olerant cv. CM67, and has lower leaf K+ concentrations. When salt was applied as a spray to the leaves, CM67 accumulated more Na+ than Chevr on, and the selection Sinis 27 (from a landrace collected on the Sinis Peninsula of Sardinia) accumulated more Na+ than Sinis 28. In some ca ses leaf K+ concentrations decreased in response to high concentration s of salt sprayed on to the leaves. Accumulation of Na+ was greater in the 4th leaf than in the flag leaf. Added CaCl2, had opposite effects when added to the salt applied to the soil or to the saline spray. In the soil, CaCl2 reduced Na+ uptake; applied to the leaf it increased Na+ uptake. Pre-wetting the leaves before the salt spray, or washing t he leaves with non-saline water 1 h after the salt spray, reduced the uptake of Na+ and Cl-. It is clear that tolerance to salt applied as s alt spray or in the soil are different characteristics.