Perusing biochemical antioxidant enzymes as selection criteria under drought stress in wheat varieties

In regard to important roles of enzymatic antioxidant in abiotic stresses, and their practical use as stress indices, the current research was implemented to peruse antioxidant enzymatic activities of different wheat varieties and to find the susceptible and the tolerant varieties based on these indices. The experiment was carried out in the greenhouse of Islamic Azad University, Sanandaj, Iran in 2015. A factorial experiment based on completely randomized design (CRD) with three replications were used to evaluate the effects of different water regimes, including 100% and 50% field capacity (FC) on 25 wheat cultivars. Antioxidant enzyme activities, including superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), and ascorbic peroxidase (APX), and grain yield of the wheat varieties were measured. The results showed that under normal irrigation condition, the relationships between grain yield and antioxidant were inversed, but under stressful condition the relationships between wheat grain yield and some important antioxidants such as CAT and SOD were positive. Among antioxidant enzymes, SOD activity showed a higher variation among wheat varieties of this study, indicating that this enzyme is an important trait to be used in the breeding programs. Based on the results of different statistical techniques and comparing relationships among traits for normal irrigation and stress condition, enzymatic antioxidant could be used as practical criteria for screening tolerant genotypes of wheat. On the other side, SOD and CAT resulted in being the most important criteria for achieving higher tolerant genotypes through indirect selection.