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- accumulation in leaves when grown in saline soil or hydroponic culture. In particular, the cv. Chevron accumulates more Na+ than the more salt-tolerant cv. CM67, and has lower leaf K+ concentrations. When salt was applied as a spray to the leaves, CM67 accumulated more Na+ than Chevron, and the selection Sinis 27 (from a landrace collected on the Sinis Peninsula of Sardinia) accumulated more Na+ than Sinis 28. In some cases leaf K+ concentrations decreased in response to high concentrations 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 the 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 salt spray or in the soil are different characteristics.