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 eight 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 significantly reduced the vegetative growth, water use, grain and straw yields for 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- concentrations in cell sap expressed from leaves. There was more Na+ and Cl- accumulation in wheats than the amphiploids in hypoxic conditions 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 Thinopyrum elongatum amphiploid was the most tolerant of the three amphiploids.