Effect of Salinity Stress on Some Biochemical Characteristics of Three Quinoa Varieties

Salinity stress is one of the most important factors that affects the quality of crops. In order to investigate the influence of salinity stress on physiological and biochemical characteristics of different quinoa varieties, an experiment was conducted as split plots based on a randomized complete block design with three replications, in Yazd city in the agricultural year 2017-2018, under field conditions. Irrigation with saline water (0, 10 and 17 dS/m) was considered as the main plot and varieties (Nsrcqe, Nsrcqb and Titcaca) as the sub-plot. The results showed that salinity and varieties significantly affected DPPH radical scavenging activity, phenol, flavonoid, anti-inflammatory and Na+/K+ ratio, as well as seed protein and saponin contents. Irrigation with saline water at 17 dS/m level increased the antioxidant activity of DPPH (19%), the antioxidant activity of grain measured using the copper ion reduction method (25%), the antioxidant activity measured by the iron reducing power method (50 %), grain protein (30.5 %), and the anti-inflammatory activity (30.5 %), whereas it reduced the grain saponin content (15%), and the sodium to potassium ratio (73.6 %) compared to the control. Results indicated that the salinity also elevated the content of collagenic acid, paracoumaric acid, quercetin acid and camphor acid in quinoa grains. Among the studies varieties Nsrcqb showed the highest amount of antioxidant and anti-inflammatory activity but had no significant difference with the Titcaca in most examined traits. The results of this experiment showed that cultivation of Nsrcqb variety and irrigation with saline water at 17 dS/m can increase the antioxidant and anti-inflammatory properties of quinoa.