Genotoxic impact of cadmium on root meristem of Vicia faba L.

Genotoxic studies with reference to pollution biomonitoring is a recent approach and can be used for maintenance of crop productivity. Effect of the cadmium chloride in the pure germ line of broad bean (Vicia faba L.) were evaluated in relation to the chromosomal abnormalities and rate of cell division. Seeds grown in the nutrient medium for 48 hrs containing different concentrations of cadmium chloride (control, 0.05 mM, 0.1 mM, 0.2 mM, 0.4 mM and 0.8 mM) showed different genotoxic effects such as polyploidy, multipolarity, chromosomal bridge with fragments, lagging chromosome and micronuclei. Relative division rate (RDR) was decreased with increasing cadmium concentration while relative abnormality rate (RAR) increased suggesting that cadmium may cause genetic changes in pure germ line and produce irrepairable damage in root meristem. Therefore, combining plant bioassays and root analysis of Cd++ content would allow us to define phytotoxicity thresholds in plants.