Sea water irrigation:: Antioxidants and quality of tomato berries (Lycopersicon esculentum Mill.)

The aim of the present research was the evaluation of sea water irrigation on fruit yield and quality in tomato grown in semi-closed substrate (rockwool) culture under greenhouse. The plant were irrigated with nutrient solution with electrical conductivity (EC) of 3.0, 8.0 and 14.0 mS/cm, which corresponded approximately to 0, 10 and 20% of salt concentration of sea water). Fruit quality was evaluated by chemical-physic characteristics, and their antioxidant capability by the analysis of reduced/oxidised ratios of the major antioxidants (ascorbate and glutathione). Besides, it was determined the activity of glutathione reductase (GR), catalase and ascorbate peroxidase (APX), the production of H2O2, the quantity of glucose and of mineral elements (K+ and Na+). The crucial role of lipoic acid, an important interplay in the regeneration of GSH and AsA, was pointed out in the regulation of cellular redox state.