THE EFFECTS OF HEAVY METALS ZN AND CD ON THE GROWTH AND SOME PHYSIOLOGICAL CHARACTERISTICS OF SPINACH (Spinacea oleracea L.)

Different concentrations of Zn and Cd (0, 2 and 4 mg L-1) were tested on the growth and some physiological traits of two spinach cultivars (common seed and Thorny seeds) as factorial based on Completely Randomized Design. The results revealed that the highest plant fresh weight was attained by 2 mg L-1 of Zn treatment. For dry weight, the highest data was belonged to Thorny seeds and the tallest plants were belonged to common seed spinaches. The top catalase content was belonged to 4 mg L-1 Zn with thorny seed. H2O2 content was affected by 2 mg L-1 of Cd in common seed cultivars. The highest Cd content in plant was measured with 4 mg L-1 of Cd at both cultivars. The greatest Zn content was recorded by Thorny seed spinach × leaf sample of 4 mg L-1 Zn and with common seed × leaf sample of 2 mg L-1 Zn.  For K+, the highest data was gained by Thorny seeds spinach × leaf sample of 4 mg L-1 of Zn, Thorny seeds spinach × root sample of 2 mg L-1 Zn and common seed × root sample of 2 and 4 mgL-1 of Zn. For Ca 2+ concentrations, Thorny seeds spinach × leaf sample of controls had the highest content. The highest Mn2+content was recorded by common seeds × leaf sample of 2 and 4 mg L-1 of Zn treatment. The evaluation of the tolerant plants having reasonable growth potential under the excess metal contaminated soils is quite emergent. Since, spinach is a fast growing and multi harvest plants during a year and, there is some reports on the hyper-accumulative behavior of the plant. So, it seems that the plant would be a nice candidate for the phytoremediation ideas and applications.