M. Keshtegar, A.R. Akbari Moghaddam, S. Mirshekari, M. Hosseini and S. Akhondi
Abstract
Thyme is a perennial herb of the mint family and is native to the Mediterranean. It has Lance-shaped small and green leaves, ranging from 6 to 12 mm long, short and square stem at the bottom of the wooden stem and it is green in its younger part. Copper (Cu) and Plumbago (Pb) are of heavy metals that its toxic effects in different plants are to be examined from different physiological, biochemical, molecular, cellular and genetic aspects. In this research, the toxic effect of copper and plumbago on some morphological and physiological traits of Thyme was examined. Copper metal in the form of copper sulfate at density of 0, 150, 300 and 400 mg per kg of dry soil and plumbago in the form of plumbago nitrate, 0, 200, 400, 600 mg per kg of dry soil and simultaneous application of the two metals with determined density was used. After the growth of the plants for four weeks in the contaminated soil, aerial part height, root length, wet weight and dry weight of aerial and root organs, Proline and lipid peroxidation level in the leaves were measured. The results of the present research suggest the negative and toxic effect of heavy metals copper and plumbago on Thyme, generally with increase of copper and plumbago density in the growth environment, growth indices have reduced. In exploration of the effect of copper and plumbago on Proline and lipid peroxidation in Thyme, an immense influence of the two metals on the above-mentioned indices in the plant was seen.