Physiological Aspects of Adaptive Strategy of Pumpkin Plants to Copper Effect Under Conditions of Chloride Salinity

An analysis of specific character of physiological responses of pumpkin plants to individual and complex action of copper and chloride salinity was made. The linear growth of different plant organs, the bioaccumulation of biomass, various forms of nitrogen and soluble proteins and dynamics of activities of proteolytic enzymes in them depending on the duration of toxicant influence (7, 14, 21 days) were determined. In the case of combined application of Cu and NaCl, the plants underwent sinergic, a more intensive inhibitory effect compared to either stress applied alone. It showed up both on a surface appearance of plants (decreasing of plant turgor, appearance of necrotic spots on the leaves and darkening of roots) and by a reduction of growth criteria, shap falling of biomass accumulation and contents of protein nitrogen and proteins, especially in the roots, in the retaintion of activities of proteolytic enzymes in them almost at the level of control plants. All of this indicates the comporative higher susceptibility of pumpkin roots to Cu- induced toxicity at salinity as compared with the shoots and generally about the low speciesspecific tolerance of Cucurbita pepo L. to copper under these conditions.