Effects of lead and cadmium ions on water balance parameters and content of photosynthetic pigments of prairie cordgrass (Spartina pectinata Bosk ex Link.)

The aim of the work was to assess the impact of a varied level of soil contamination with lead and cadmium ions on selected physiological parameters of prairie cordgrass. The content of photosynthetic pigments in leaves (chlorophyll a, b, total chlorophyll and carotenoids) and water balance of plants on the basis of two indicators (RWC – relative water content in tissues and WSD – water saturation deficit) were determined. Pot-vegetative experiments were performed using a complete randomization method in a one-factor system. The factor in the first experiment was the level of soil contamination with lead (28.15, 56.30, 112.60 mg Pb · kg soil–1), in the second experiment – the level of soil contamination with cadmium (4.60, 10.00, 18.39 mg Cd · kg soil–1). The levels of soil contamination with lead did not influence the content of chlorophyll a, b and total chlorophyll in prairie cordgrass leaves. In the case of carotenoids, an increase in their content was demonstrated after introducing lead into the soil at the dose of 28.15 mg Pb · kg soil–1 compared to the control. Soil contamination with cadmium did not affect the content of chlorophyll a, total chlorophyll and carotenoids in the leaves of prairie cordgrass. The highest level of soil contamination with lead contributed to the reduction of chlorophyll b. Lead at doses of 56.30 and 112.60 mg · kg soil-1 caused deterioration in the water balance parameters of the prairie cordgrass. In the case of soil contamination with cadmium, this relationship was demonstrated only for the dose of 10.00 mg Cd · kg soil–1.