Фітотоксичність забруднених важкими металами ґрунтів м. Миколаєва

Abstract

Исследовано содержание тяжелых металлов (Cd, Mn, Cu, Ni, Pb, Zn) в почвах на территории ряда предприятий г. Николаева. Доказано их фитотоксическое воздействие на проростки озимой пшеницы. Исследована корреляционная зависимость между содержанием тяжелых металлов в почве и содержанием хлорофилла, весом, ростом растений, содержанием аскорбиновой кислоты, сухого вещества и активностью пероксидази в растениях.

The study is dedicated to the phytotoxicity of soils collected from some industrial objects in the city of Mykolayiv (Ukraine). These soils were analyzed to determine the content of Cd, Mn, Cu, Ni, Pb and Zn. Contamination with the heavy metals have been proved for the examined soils as the permissible upper critical level of one or more metals was exceeded in each soil sample. Winter wheat sprouts were used to test the toxicity of the soil samples. The reference soil was taken from non-polluted agricultural land. The parameters of the sprouts were evaluated in two weeks after germination. Soils from the industrial objects have been proved to cause phytotoxic effect on the wheat sprouts. Decreasing of the draw mass and shoot length were observed on the contaminated soil samples. The amount of chlorophyll in leaves also became 18- 29% lower. Some soil samples caused 3-130 % increasing of the ascorbic acid content, and 14-34 % dry mass content. Contamination also resulted in lowering the content of protein up to 4 times and in 70-160 % growing peroxidase activity. There is correlation between heavy metals’ content in soil and some physiological and biochemical indices of the testobject plants. It points to the mechanisms of the phytotoxic effect of these metals. Negative correlation was proved between content of chlorophyll in wheat sprouts and content of cadmium, manganese and copper in the soil. Negative correlation is also observed between ascorbic acid content in plants and levels of cadmium, manganese and copper; between dry mass content and levels of cadmium, copper and zinc; between levels of peroxidase activity in the sprouts and levels of cadmium and copper in the soil.