The impact of Zn and Cd heavy metals on the growth and some physiological characteristics of spinach ینابرهم يدوجو ایمل

High concentrations of heavy metals disrupt the metabolic processes of plant growth and even cause plant death. Plants show different tolerance thresholds to heavy metals, therefore, the effect of different concentrations of heavy metals zinc (Zn) and cadmium (Cd) (zero, 2 and 4 mgL) in two varieties of spinach (common seed and Thorny seeds) on some morphological, physiological traits and content of the elements were examined in the factorial experiment based on a completely randomized design with three replications. The results showed that some morphological traits of the plant are affected by metals and cultivar type independently, so that the lowest wet weight of leaves and plant height was observed in four mgL of Cd treatment and the highest amount of these two traits was observed in two mgL of Zn. The highest dry weight of the plant was recorded in the thorny cultivar and the highest plant height was recorded in the normal seed cultivar. The interaction of the type of cultivar and heavy metals was significant in some physiological traits such as soluble solids content, catalase content, and superoxide dismutase. The highest activity of catalase enzyme was observed in the treatment of 2 mgL of Cd in normal seeds and the highest amount of superoxide dismutase was observed in the treatment of 4 mgL of Zn and 2 mgL of Cd in normal seeds. Zinc metal up to 2 mgL increased the growth and development of spinach, but more than this amount, like cadmium metal, reduced yield and increased the amount of antioxidant enzymes. All content of the measured elements showed a significant interaction. As the cadmium increased, the plant's uptake of the Ca, K, Zn, Mn and Mg decreased, so that the lowest amount of all the elements measured in four mgL of Cd was observed in thorny seeds. The results of determining the biological concentration in this experiment showed that the cadmium content of thorny and common spinach leaves varied between 145 and 167 mgKg and spinach could be a good representative for use in cadmium phytoremediation.