EVALUATION OF CALCIUM CARBIDE'S CYTOTOXIC EFFECTS ON ONION (Allium cepa)

Abstract

The purpose of this investigation was to see if Calcium Carbide (CaC2) had any harmful effects on onions (Allium cepa L.). Allium cepa root tips were grown in various concentrations of Calcium Carbide (CaC2) (0.25g, 0.50g, 0.75g, and 1.00g)/ 250ml, with distilled water serving as a control. For cytological tests, the root tips of Allium cepa growing in the treatments and control were removed daily between 7:30am and 8:30am. Pretreatment, fixation, hydrolysis, squashing, and staining of cells for mitotic investigations were performed, and data on cytological parameters were collected using a light microscope at a magnification of X40. The mitotic index (MI) and karyotype analysis were used to assess the data collected on these parameters. The results of this study showed that root tips treated with 0.25g of Calcium Carbide (CaC2) have a mitotic index of 45.83 and the rate of cell division decreases with an increase in the concentration of Calcium Carbide (CaC2) as the cell divides the mitotic index dropped sharply. These finding indicated that Calcium Carbide is a strong mitotic inhibitor and could give rise to mitotic abnormalities with increase in concentration and also reduced cell division. We therefore recommended that there is need for further investigation using lower concentrations of Calcium Carbide as well as other mutagenic substances in order to ascertain their effect on the chromosomal behavior.