Determination of Mitotic Index and Evaluation of Cytogenotoxicity of Oxyfluorfen Using Allium Cepa Root Tip Meristematic Cells

Abstract

The present study aimed to investigate Oxyfluorfen induced cytogenotoxicity employing Allium cepa meristematic cells as test models. The root length inhibition was determined exposing the meristematic cells to eleven Oxyfluorfen concentrations such as 0.01, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9ppm and 1ppm against controls and the inhibition was statistically (p<0.05) significant at 0.2, 0.3, 0.4, 0.7, 0.8, 0.9 and 1ppm and insignificant for the rest. The root length was drastically reduced at 0.3ppm and complete at 1ppm. The significant change in cell shape and structure was observed at 0.4 & 0.5ppm when compared to 0.01 & 0.1ppm. The mitotic index was calculated considering interphase, prophase, metaphase, anaphase and telophase as cell cycle stages out of one thousand cells. The per cent mitotic index of 0.01, 0.1, 0.2, 0.3, 0.4ppm and 0.5ppm concentrations was found to be 49, 32.8, 29.4, 0, 32.8 and 51.4 respectively and this result significantly correlates with root length inhibition studies. Cell cycle check points will block or delay the progression of mitosis due to pesticide interference with mitotic phase duration, making some phases more frequent than others. Therefore, it is established that Oxyfluorfen is cytogenotoxic to Allium cepa meristematic cells and this technique is very convenient to assess how toxic substances bring abnormality at cell and organelles level.