Salinity increased vitamins concentration in Amaranthus cruentus leaves

Salt stress is one of the major environmental constraints limiting agricultural productivity and influencing the concentration of bioactive compounds of vegetables. In this study, the effect of NaCl salt stress on nutrient contents of leaves in a cultivar of amaranth, an important leafy vegetable cultivated in some tropical regions worldwide, was evaluated. The experiment was carried out in a screen house at Center for Agricultural Research of Agonkanmey, Benin Republic as a randomized complete block design (RCBD) with three replications. Three weeks old plants were subjected in pots containing a mixture of potting soil and sand, to three concentrations (0, 30 and 90 mM) of NaCl by irrigation every two days. Nutrient contents in leaves were determined at maturity, after four weeks of stress, using standards methods. Proteins, total sugars, reducing sugars, lipids, potassium, calcium, vitamins C and B3 contents were not significantly affected by NaCl. Iron content increased significantly only at 30 mM NaCl but vitamins A, B1 and B2 contents increased significantly with increase in NaCl concentration. Thus, salt stress did not reduce nutritional values of this amaranth cultivar but improved its leaves nutritional quality by increasing vitamins A, B1 and B2 content.   Key words: Amaranth, NaCl, proteins, lipids, sugars, mineral, vitamins.