Evaluation of important physiological traits of Morvared and Falat bread wheat cultivars under heavy metals cadmium and mercury

Environmental pollution caused by heavy metals due to their non-degradability is a major concern in agricultural soils that threatens food security. Cadmium and mercury are among the two dangerous and carcinogenic pollutants that, in natural ecosystems are increased by human activities and lead to a decrease in protein production, the deactivation of some enzymes, disruption of various reactions and cellular actions, and the stoppage of growth and development. Since the contamination of agricultural land with heavy metals, on the one hand, leads to a decrease in the quality of agricultural products and, on the other hand, is a serious threat to human health, it needs more attention. Therefore, the purpose of this research is to investigate the effect of replanting wheat seeds resulting from the treatment of heavy metals such as cadmium and mercury on some morphophysiological parameters of two wheat cultivars. For this purpose, a factorial experiment was conducted in the form of a completely randomized design with three replications in the greenhouse of the University of Mohaghegh Ardabili. The first factor of wheat cultivars (Morvared and Falat) and the second factor of the experimental treatments include mercury chloride (with a concentration of 10 and 20 μM), cadmium chloride (0.5 mM), and the interaction effects of cadmium with mercury at two levels (10 μM of mercury with 0.5 mM cadmium, 20 μM mercury with 0.5 mM cadmium) were with the control seedlings. The findings showed that, except for the treatment with cadmium under the stress of the toxic metal mercury and the interaction effect of cadmium with mercury, the amount of soluble sugar and total protein, the activity of the catalase enzyme increased, but the activity of the antioxidant enzymes peroxidase and polyphenol oxidase decreased in the Morvared cultivar. The results indicate that the seeds obtained from the foliar treatment of cadmium, mercury and the interaction of these heavy metals and the re-cultivation of these seeds can affect their performance by changing the physiological characteristics. In general, under the stress of mercury chloride and cadmium chloride and their interaction, the Morvared cultivar showed a better reaction than the Falat cultivar. Therefore, based on the results of this greenhouse experiment, it seems necessary to continue research in field conditions.