Influence of increased salinity on physiological responses of hydroponic grown tomato (lycopersicon esculentum mill.)

Hydroponic cultures were used to evaluate salt stress responses in two (JO112 and JO992) tomato (Lycopersicon esculentum Mill.) genotypes. Hydroponic cultures were grown on media supplemented with 0, 50, 100, 150 and 200 mM NaCl and CaCl2 in equal molar ratio, growth and physiological traits were determined. Negative response had happened in growth parameters (FW (fresh weight), DW (Dry weight) and shoot height). Na+, Cl- and Ca+² ions and proline concentrations increased in both cultivars of hydroponically grown plants with increase in salinity. In contrast, K+ ions decreased with increase in salinity. Induced salinity significantly reduced more negative) cell sap osmotic potential. The genotype JO992 generally had higher shoot and root fresh weight, dry weight, shoot height and root length than JO112. The results indicate that, in both genotypes, osmotic adjustment was achieved by means of Na+, Cl¯ and Ca+² ions uptake from the medium and by synthesis of proline. Hydroponic cultures were used to evaluate salt stress responses in two (JO112 and JO992) tomato (Lycopersicon esculentum Mill.) genotypes. Hydroponic cultures were grown on media supplemented with 0, 50, 100, 150 and 200 mM NaCl and CaCl2 in equal molar ratio, growth and physiological traits were determined. Negative response had happened in growth parameters (FW (fresh weight), DW (Dry weight) and shoot height). Na+, Cl¯ and Ca+² ions and proline concentrations increased in both cultivars of hydroponically grown plants with increase in salinity. In contrast, K+ ions decreased with increase in salinity. Induced salinity significantly reduced (more negative) cell sap osmotic potential. The genotype JO992 generally had higher shoot and root fresh weight, dry weight, shoot height and root length than JO112. The results indicate that, in both genotypes, osmotic adjustment was achieved by means of Na+, Cl¯ and Ca+² ions uptake from the medium and by synthesis of proline.