Salinity effects on growth, ion distribution, carbohydrate metabolism, and photosynthetic rate in soybean cultivars differing in their tolerance to salinity stress

Effects of sodium chloride on growth, ion distribution, photosynthetic capacity, and carbohydrate metabolism were investigated in soybean (Glycine max (L.) Merr. cvs Bragg (salt sensitive) and Ransom (salt semi-tolerant)). Plants were grown in aerated nutrient solution supplemented with 0 to 100 mM NaCl.;The concentrations of Na;Salinity severely reduced net photosynthesis (Pn) in Bragg but did not significantly affect Pn of Ransom. Pn reduction in Bragg was associated with accumulation of Na;Proline did not accumulate in Ranson leaves; and, although it did in Bragg, accumulation seemed a response to rather than an alleviator of injury. Ransom leaf solute potential was maintained about 1.1 MPa below solution water potential; whereas that of Bragg declined much more rapidly. The latter resulted primarily from salt accumulation, proline having little effect.