Cytogenetic Effects of Radiation from Projector on Meristematic Cells of Allium Cepa (Onions) Root

Abstract

The objective of this study is to evaluate the cytogenetic consequences of exposing root tips of Allium cepa (onion) to varying distances and durations of radiation from the projector and treatment with sodium azide and distilled water using standard methods. The sodium azide and distilled water served as positive and negative controls respectively. Results obtained in this study revealed that radiations from the projector induced eleven chromosomal aberrations which included; binucleate cells, sticky chromosomes, vacuolated cells, star metaphase, bride chromosome, vagrant chromosome, faculty polarity, C-mitosis, spindle fibre disturbance, ghost cells, and fragmented chromosomes. This suggests that radiation from the projector poses danger to genetic systems. The higher mitotic index of irradiated onion root tip cells compared to negative control groups indicates that radiation from the projector exhibited a promontory effect on cell division. The findings in this study revealed that exposing cells to radiation beyond 20cm from projector reduced its potencies to induce aberrations as well as distortion of mitotic cell division cycles irrespective of the duration of exposure. This suggests that the genotoxic effects of radiations from a projector depend more on distance than the duration of exposure.