combined effects of salinity and Ca [No3] 2 of KNO3 on growth and metabolism of phaseolus vulgaris

ABSTRACT

Additional Ca[NO3]2 or KNO3 to media salinized with NaCl appeared to improve growth and metabolism of Phaseolus vulgaris. Ca2+ and K+ concentrations increased in both shoots and roots with increasing their concentration in the medium whereas Na+ concentration was greatly decreased. With the decrease in internal Na+ concentration, the concentrations of reducing sugars, sucrose and in consequence total carbohydrates were increased. However, the increase in sugars at 60 mM K+ was greater than at 40 mM Ca2+ although the internal Na+ concentration was similar in shoots [0.2 mmol/g dry weight]. Also, protein concentration was greatly increased, whereas soluble nitrogenous compounds were decreased with increasing either Ca2+ or K+ in the salinized medium. This suggests that Ca2+ and/or K+ as nitrate salts could be added to NaCl salinized media to overcome the deleterious effects of salinity on growth and ameliorate the productivity of leguminous crop plants