Toxicity of Heavy Metals that Affect Germination, Development and Cell Cycle of Allium cepa L

This study aimed to investigate the impact of heavy metals copper, cadmium, lead, aluminum and nickel, on the growth, physiology, metabolism, and cell cycle of Allium cepa L. Five treatments with increasing concentrations (0, 50, 100, 250, and 500 µM) were applied to the seeds. The results showed that the highest concentrations of copper and cadmium had phytotoxic and biochemical effects on the onion. Additionally, copper concentrations caused an increase in mitodepressive effect and chromosomal abnormalities. Aluminum also induced several chromosomal abnormalities. The study found that Cd > Cu > Pb > Ni > Al and Cu > Al > Ni > Pb > Cd had the highest phytotoxic and cytotoxic potentials, respectively. Furthermore, the UPGMA method revealed three divergent groups. These results suggest that heavy metals, especially copper, have a significant pollution potential when present in high concentrations.