Salinity Stress Promote Drought Tolerance of Chenopodium Quinoa Willd

A greenhouse experiment was conducted to investigate the impact of water and salt stress in Quinoa plants (Chenopodium quinoa Willd.). Irrigation treatments using saline solutions of 0 (control), 50(T-1), 200(T-2), 400(T-3), 600(T-4), and 800(T-5) mM sodium chloride (NaCl) were adopted. The results indicated that quinoa plants can tolerate water stress (50%FC) when irrigated with moderately saline water (T-1 and T-2, respectively). Salinity stress increases quinoa drought tolerance in terms of biomass production. Neither osmotic stress nor ions deficiency/toxicity seems to be determinant under T-1 and 100%FC. Salinity induced a significant increase of sodium (Na+) and chloride (Cl-), while reduced magnesium (Mg2+) and calcium (Ca2+) in stems, leaves, seed's coating, and seeds. The potassium (K+)/Na+ ratio never fell below 1 with T-1; yet, fell to 0.78 and 0.89 with T-2 for 100% and 50%FC, respectively. The seed coat limited the passage of possibly toxic concentrations of Na+ and Cl- to seed interior, as high Na+ and Cl- was found in the seed coat.