8. Metal Phytotoxicity: Suitable Indicators and Tests for Ecotoxicological Evaluation of Contaminated Soils

Metal phytotoxicity is a topical problem in a part of soils contaminated by heavy metals. Nonspecific chlorosis and necrosis are visual toxicity symptoms in plant organs. Heavy metal-induced structural-functional disorders lead to growth retardation and decreased plant productivity. The biological quality of the contaminated soils is evaluated through biotests, including phytotests. In the present review-paper it is shown that a number of physiological parameters, such as growth rate, antioxidative enzyme activities, photosynthetic pigments content, etc. have high sensitivity to heavy metals and may be used as indicators of metal phytotoxicity. Data concerning both the development of a new test with cucumber plants and its application for evaluation of phytotoxicity of metal-contaminated soils are presented.