EFFECT OF SALINITY STRESS ON ANTIOXIDANT ACTIVITY AND GRAIN YIELD OF DIFFERENT WHEAT GENOTYPES

Abstract

In order to evaluate the antioxidant activity of wheat in salinity stress conditions, an experiment with 27 wheatgenotypes grown on two types of soil was conducted: solonetz (increased salinity) and chernozem (control),during two vegetation seasons (2015/2016 and 2016/2017). Analysis of DPPH radical scavenging activity andphenolic content (PC) were performed in different phenophases of wheat (tillering, stem elongation andheading). Genotypes showed significantly higher DPPH radical scavenging activity (9.82 mg trolox equivalents(TE) per mg of dry matter (d.m.)) and PC (8.15 mg gallic acid equivalents (GAE) per mg d.m.) under salinitystress conditions compared to values obtained on control (8.52 mg TE mg-1 d.m. and 7.13 mg GAE mg-1 d.m.,respectively). All analyzed factors (genotype, soil type and year) had the highly significant influence onphenotypic variation of grain yield. Salinity stress reduced grain yield by 30%, whereas drought stress in2016/2017 vegetation season reduced grain yield by 20%. Highly significant and positive correlations arepresent between grain yield and parameters of antioxidant activity in all growth stages of wheat and both soilconditions. Therefore, it could be possible to select salinity tolerant genotypes in early growth stages. DPPHscavenging activity and total phenolic content are in highly significant and positive correlation in all growthstages, which indicates that antioxidant activity is highly derived by phenolics.