Effect of gamma irradiation or potassium on oxidative stress and antioxidant system of cadmium stressed Brassica rapa (L.) plant

The effect of cadmium chloride concentrations (25.50, 75, and 100 mg/kg soil), seeds pre‐irradiated by low doses of gamma rays (15, 30, 45, and 60 Gy), potassium chloride (60 mg/kg soil) and the combination of cadmium gamma and cadmium potassium on Brassica rapa germination, oxidative stress and antioxidant system were investigated under laboratory and greenhouse conditions. Germination percentage decreased progressively by increasing cadmium chloride concentrations. Gamma irradiation and potassium treatment enhanced the germination and reduced cadmium toxicity when combined with it. All of the treatments relatively caused overproduction of H2O2. Peroxidase and catalase activities were increased by the cadmium concentrations while ascorbic acid was decreased.