The phytoextraction is a process that uses living plants for cleaning up the heavy metals from contaminated soil. The cadmium and lead contamination of soils results from the application of sludge or urban composts, fertilizers, pesticides, motorization, metallurgy, and different technological processes. In industrial terrain the content of cadmium and lead in soils has increased in the recent years. This study was undertaken to evaluate the potential of Amaranthus caudatus L. ‘Atropurpureus’ and Ricinus communis L. ‘Sanguineus Apache’ for phytoextraction of cadmium and lead. Two species of ornament plants, i.e. Amaranthus caudatus L. ‘Atropurpureus’ and Ricinus communis L. ‘Sanguineus Apache’, were planted in drainless containers in a substrate artificially polluted with cadmium and lead in order to evaluate their suitability for phytoremediation of soils or substrates contaminated with these metals. Cadmium was applied at increasing rates of 0, 1, 5 and 10 mg Cd∙dm-3 in the form of cadmium sulfate 3CdSO4∙8H2O, while lead was used at 0, 100, 500 and 1000 mg Pb∙dm-3 in the form of lead acetate (CH3COO)2Pb∙3H2O. The applied doses of cadmium and lead in the experiment reflected different degrees of soil pollution. After five months of growth it was found that Amaranthus caudatus L. accumulated the biggest concentrations of cadmium and lead in leaves and the lowest concentrations in inflorescences. Ricinus communis L. accumulated the highest concentrations of cadmium in stems, while the lowest concentrations in inflorescences, whereas the biggest concentration of lead was accumulated in inflorescences and the least lead was accumulated in leaves. The biggest reduction of cadmium and lead concentrations after the completion of the experiment was found in substrates, in which Amaranthus caudatus L. was grown. The tested species of ornamental plants may be used in the phytoextraction of cadmium and lead from soils contaminated.

Abstract Nutrition is one of the most important factors influencing quantitative and qualitative plant yield. This study examined the effect of manganese (Mn) in nutrient solution on photosynthetic activity parameters, and the relations between photosynthetic activity parameters, yield and plant nutrient status in tomato (Solanum lycoper-sicum L.). Mn supplementation significantly modified the nutrient content of leaves. Macronutrient content var-ied less than micronutrient content. The optimal Mn concentration differed between the studied cultivars. Both Mn deficit and Mn excess caused a decrease of tomato yield. Gas exchange parameters, relative water content (RWC) and specific leaf area (SLA) were measured in fully expanded tomato leaves. Certain levels of Mn were found to be needed for proper plant function and future yield, and toxic effects of excess Mn were noted. Changes in PN (net photosynthetic rate) were found to be the first signal of plant response to higher Mn supply, while yield was as for optimal Mn concentrations. Under Mn treatment, uptake of some nutrients increased. A higher level of absorbed Mg led to a higher photosynthesis rate and increased stomatal opening. PN and gs (stomatal con-ductance) also increased, while Ci (intercellular CO2 concentration) decreased, indicating proper CO2 consumption during the assimilation process.