EN
The distribution of lead in root tips of Dianthus carthusianorum was compared in populations from a zinc-lead waste heap in Bolesław near Olkusz and from a natural stand in the Botanical Garden in Lublin. The analyses were made at two developmental stages: seedlings (after 8 days of incubation in 5 mg/dm3 Pb+2 from PbCl2 in 1/8 Knop medium) and mature plants (after 23 days of incubation in 10 mg/dm3 Pb+2 from PbCl2 in 1/2 Knop medium). Histochemical methods (rhodizonate and dithizonate) of lead detection revealed significant accumulation of this metal on the root surface of the examined plants. The site of next-strongest lead accumulation in root tips of plants from both populations was in cell walls of the pericycle. The layer of meristematic pericycle cells seemed to be a strong barrier against penetration of lead to the deepest cells of the procambium. Histochemical methods and tissue sections revealed no differences in lead distribution between root tips from the waste heap and from the natural population, but differences were detected on the ultrastructural level. There were numerous lead deposits in the cytoplasm of cells from ground meristem in the natural population, and none in specimens from the waste heap, indicating that lead had a higher toxic effect on the natural population of D. carthusianorum.