Antioxidant activity of various wheat genotypes grown under salinity stress

In order to evaluate the antioxidant activity of wheat in salinity stress conditions, an experiment was conducted with 27 wheat genotypes, grown on two types of soil: solonetz (increased salinity) and chernozem (control). Analysis of DPPH scavenging activity and phenolic content (PC) were performed in different phenophases of wheat (tillering, stem elongation, heading and full maturity). Genotypes showed significantly higher DPPH scavenging activity and PC under salinity stress conditions (6.08 mg trolox equivalents (TE) per mg of dry matter (d.m.) and 7.27 mg gallic acid equivalents (GAE) per mg d.m., on solonetz, and 4.42 mg TE mg-1 d.m., 6.16 mg GAE mg-1 d.m., on chernozem). The highest antioxidant activity and PC under salinity stress was found in growth stage of stem elongation (10.91 mg TE mg-1 d.m. and 10.09 mg GAE mg-1 d.m.), while on chernozem, genotypes had the highest antioxidant activity and PC in the growth stage of heading (6.08 mg TE mg-1 d.m. and 7.74 mg GAE mg-1 d.m.). Highly significant and positive correlations are present between grain yield and parameters of antioxidant activity, in all growth stages of wheat and both agro-ecological conditions. Therefore, it could be possible to select salinity tolerant genotypes in early growth stages.