ION UPTAKE, OSMOREGULATION AND PLANT-WATER RELATIONS IN FABA BEANS (VICIA-FABA L) UNDER SALT STRESS

In pot experiments, the effects of irrigation with artificial seawater on faba beans were investigated. The sum of the salt concentration wa s 0, 20, 40 and 60 mM (NaCl: MgCl2:MgSO4 = 2:1:1 on molar basis). Salt stresses increased the concentrations of sodium, magnesium and chlori de ions in the plants. Sodium reduced the uptake of potassium due to i on antagonism. Decreased iron concentrations induced chlorosis. Chlori de antagonized the uptake of nitrate. Phosphate increased significantl y in response to ion balance. Significant increases in glucose, fructo se, in some cases sucrose, proline and calcium contents in faba beans showed some tendency of this crop to adjust osmotically against salt s tress. Salinity reduced leaf water potential (PSI(t)) as well as osmot ic potential (PSI(s)). Leaf water potential (PSI(t)) decreased from -9 x 10(5) Pa under control conditions to -14 x 10(5) Pa under severe sa lt stress. Grain as well as straw yields of Faba beans were decreased significantly by artificial salinity. At the highest stress level (60 mM salt) grain yields were reduced by 85 %, while straw yields decreas ed by 43 % at 60 mM.