Effects of salinity on the nutritional quality of amaranth (Amaranthus cruentus) leaves: case of local and resistant varieties

Abstract

Climate change is a real obstacle to agriculture because of the difficulty of water supply. Farmers are trying to mitigate this problem by developing several strategies including those based on irrigation. Unfortunately, these irrigation techniques favour the entry of sodium in food crops. In response to this situation, research has been conducted in Benin to develop a salinity resistant variety of local amaranth (called line 23). The objective of this study is to determine the nutritional values of this resistant amaranth variety grown under salt stress and to compare them with the nutritional values of local amaranth grown under the same conditions. Local and resistant amaranth plants were grown in real environment and then stressed with salt concentrations of 0; 7.1 and 19.6 mmol NaCl. After harvesting, the leaves were sent to the laboratories for the determination of nutritional elements. Three replicates were done. Analysis of variance was used to compare the means of the nutritional elements assayed using JMP software (SAS Institute MC 2007). The results show a significant improvement in calcium, phosphorus, potassium and vitamin A levels in line 23 in contrast to the reference cultivar. However, the sodium content, although decreasing as the salt concentration increases, remains above acceptable limits. As for the reference cultivar, the results show an increase in the concentrations of several elements: iron, calcium, magnesium, including that of sodium, which is harmful to cardiovascular health.