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High levels of Co(NO3)2 for living organisms are toxic. In this study, the protective effects of 2,6-dimethyl-morpholine dithiocarbamate (DMMDTC) against the toxicity of Co(NO3)2 on Allium cepa L. were investigated. Seven groups of onion bulbs were established to investigate the potential effects of DMMDTC against Co(NO3)2 exposure in root tips. These are a control group, two groups of DMMDTC alone in different concentrations, two groups of Co(NO3)2 in different concentrations, and finally, two groups of combined DMMDTC (1,2) + Co (1,2) in different concentrations were applied to onion roots. The effects of the chemicals on physiological parameters, Mitotic Index (MI), Micro Nucleus (MN), genotoxicity and Co(NO3)2 accumulation in the roots were examined. MI analysis revealed that Co(NO3)2 treatments reduced the MI compared to water control by 52.2-46.6%, depending on the concentration. The combinations of DMMDTC + Co(NO3)2 significantly increased MI while decreasing MN compared to the cobalt-only treatments. However the protective effect of DMMDTC against cobalt toxicity was limited when the data compared to the water control. The heavy damage to epidermis cells and nucleus was also observed in those cobalt applied groups. Co(NO3)2 accumulation in the roots, compared to water control, was also high in Co1-Co2 groups. The DMMDTC used in this study had effects similar to those of plant extracts in reducing genotoxic effects. Therefore, the research highlights the potential benefits of using synthesized DMMDTC on Allium cepa against the toxic effects of cobalt.

来源平台：BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY