Uptake and accumulation of zinc and their effects on nutrient and chlorophyll content in seedlings

Phytoremediation is a method in which plants are used to absorb contaminants. Heavy metals significantly affect plant distributions by competing with nutrients and limiting plant growth. In this study, three-year-old seedlings of Crataegus aronia and Juniperus polycarpos were exposed to different concentrations of zinc nitrate (۰, ۵۰, ۲۵۰, and ۵۰۰ ppm) in a completely randomized design with three replications. Then, the amounts of zinc uptake in different organs of C. aronia and J. polycarpos seedlings were measured by atomic absorption spectroscopy after acid digestion and total chlorophyll content was measured with a spectrophotometer after extraction. The results obtained from the analysis of variance showed that in both species, zinc accumulation increased in roots and stems by elevating the heavy metal concentration and that zinc accumulation was higher in root tissues than in stem tissues in all treatments (p < ۰.۰۵). In addition, zinc contamination decreased the concentration of all nutrient contents in leaves and stems of seedlings, and total chlorophyll decreased by ۵۶% in J. polycarpos and ۴۷% in C. aronia. Accordingly, it can be said that the seedlings of C. aronia and J. polycarpos have the ability to prevent the transfer of the metal to aerial parts and to lower its toxicity to the plant by accumulating zinc in the roots. It should be noted that J. polycarpos was a better accumulator of zinc than C. aronia by ۳۳%.

کلیدواژه ها:

Crataegus aronia ، Heavy metals ، Juniperus polycarpos ، Phytoremediation