COMBINED EFFECT OF SALINITY AND HYPOXIA IN WHEAT (TRITICUM-AESTIVUM L) AND WHEAT THINOPYRUM AMPHIPLOIDS

The effects of sodium chloride salinity and hypoxia were studied in ei ght wheat lines and three wheat-Thinopyrum amphiploids in vermiculite- gravel culture. The lines were treated with either 100 or 150 mol m(-3 ) NaCl with and without hypoxia. Saline hypoxic conditions significant ly reduced the vegetative growth, water use, grain and straw yields fo r all wheat varieties except the amphiploids, whereas NaCl or hypoxia alone had less pronounced effects. In addition, saline hypoxic stress reduced K+ concentration and increased significantly the Na+ and Cl- c oncentrations in cell sap expressed from leaves. There was more Na+ an d Cl- accumulation in wheats than the amphiploids in hypoxic condition s at 150 mol m(-3) NaCl. Of the wheats, Pato was the most sensitive at all stress levels while a Triticum aestivum cv. Chinese Spring x Thin opyrum elongatum amphiploid was the most tolerant of the three amphipl oids.