Leaf production and quality of quinoa ‘Titicaca’ is enhanced under moderate salinity

Abstract

Quinoa (Chenopodium quinoa Willd.) is described as high nutritional value crop due to the quality and quantity of their beneficial compounds and antioxidant potential. We assess the influence of salt stress on the functional value of quinoa ‘Titicaca’ leaves and the best growth conditions to obtain both a high leaf production and optimal levels of bioactive metabolites. Thus, quinoa ‘Titicaca’ plants were grown under hydroponic greenhouse conditions with 0, 50, 100 and 200 mM NaCl. The results indicated that salinity levels of 200 mM NaCl decreased shoot biomass in a 45.1% and leaf area in a 69.1%, together with a depletion of the concentration of starch and total soluble sugars of 62.3% and 17.7%, respectively. Proline levels increased in conditions over 100 mM NaCl and total proteins decreased in all salt treatments. Furthermore, the greatest values of glutathione (368.57 mmol mg-1 dw) and ascorbic acid (0.86 mg 100 g-1 dw) were shown in plants subjected to 100 mM NaCl, and total phenolics and antioxidant enzymes activity rose in unison with the salinity severity. Results revel that quinoa ‘Titicaca’ leaves are of high nutritional value especially when cultured under moderate salinity conditions of 100 mM NaCl. Not only grains, also greens of this edible halophyte could be of interest to maximize food production in arid and saline zones.