The investigation of toxic effects of chromium ( K2Cr2O7 )'un Alli̇um cepa L.

In this study, physiological, cytogenetic and anatomic effects of Chromium heavy metal (K2Cr2O7) with different doses were investigated in Allium cepa L. Germination percentage, root length and weight gain were investigated as physiological parameters; micronucleus frequency, chromosomal aberrations and mitotic index were investigated as cytogenetic parameters. It was determined that germination percentage, root length, weight gain and mitotic index decreased, micronucleus frequency and chromosomal aberrations increased with K2Cr2O7 treatment. The most obvious toxic effect was observed in the group treated with 12.5 mg/L K2Cr2O7 treatment. Unequal distribution of chromatin, fragment, sticky chromosome, chromosome bridge, c-mitosis and reverse polarization were observed as chromosomal aberrations induced by K2Cr2O7. It was determined that the fragment formation was observed in a high rate while reverse polarization was observed in least as chromosome damage after K2Cr2O7 application. In addition, K2Cr2O7 treatment causes anatomical damages in the root tip meristematic cells as flattened cell nuclei, thickening of the cortex cell wall, cell deformation and necrosis. In conclusion, K2Cr2O7 has serious physiological, cytogenetic and anatomic toxic effects in Allium cepa and it has been determined that this effect is dose dependent.