Possible Ionic Effects of NaCl on Two Mexican Wheat Cultivars

Abstract

The effect of NaCl on growth and physiology of two Mexican wheat (Triticum asestivum L) cultivars (Cajeme: salt tolerant, and Yecora: salt sensitive) was compared with that of other osmotic agents, Na2SOa (ionic compound) and polyethylene glycol, as PEG 1000 (nonionic compound). The response of the number of tillers, total leaf area, water relations and ionic composition to these osmotic agents revealed that the effect of salt was mainly osmotic, but some specific effects of individual ions were also observed. All these compounds had similar effects on the number of tillers and total leaf area of both cultivars. Water and solute potentials of leaves were reduced as the osmotic potential of the culture solution decreased, but water potential of leaves with PEG did not decrease as much as with NaCl and NazSOq. The ionic agents, NaCl and Na2SO+, decreased K* and Ca2* in the leaves, while PEG had little effect on leaf iontent of r* ana- Ca2i lif in.r. ug"",t increased phosphorus in leaves of both cultivars, but PEG had the smallest effect. All these compounds had similar effects on the accumulation of proline in the leaves of both cultivars.