The investigation of the physiological, anatomical and genotoxic effects in Allium cepa L. of Deltamethrin

The objective of the present study was to investigate toxic effects of Deltamethrin using root tips of Allium cepa L. For this purpose, we used the germination percentage, root length, weight gain, frequency of micronucleus (MN) and chromosomal aberrations, anatomical changes with MDA levels that are indicators of oxidative stress as indicators of toxicity. Seeds were divided into 4 groups as 1 control and 3 application groups. The seeds of control group were treated with tap water only, and the seeds of application group were treated with 5, 10 ve 20 mg/L doses of Deltamethrin for 72 h. The results showed that significantly reduced the germination percentage, root length and weight gain, and the number of MN and chromosomal aberrations increased in all the application groups compared with results the control group. A dose-dependent increase of chromosome aberrations was also observed. Abnormalities scored were fragment, sticky chromosome, bridge, unequal distribution of chromatin and c-mitosis. Also, results showed that Deltamethrin at all doses caused anatomical damages such as flattened cell nuclei, necrosis, accumulation of some substances in the vascular tissue, thickening in the cortex cell walls, nonspecific vascular tissue and cell deformation. On the other hand, there was significant an alteration in the MDA levels of the root tips exposed to Deltamethrin when compared with control. Three different doses of Deltamethrin significantly enhanced the lipid peroxidation and caused an increase in MDA levels in all treatment groups, and the maximum effect was observed at the dose level of 20 mg/L. The data obtained in this study showed that Allium cepa bioassays can be used as an important indicator to detect possible toxicity of Deltamethrin. Keywords: Allium cepa L., Anatomy, Deltamethrin, Physiology, Genotoxicity, malondialdehyde