Toxic Effects of Some Heavy Metals Using Plant Chromosomal Aberrations Assays
Yadav Somesh, Singh Hitendra Kumar, Saxena Meenu
Lab. of Plant Cytogenetics, Dept. of Botany, Bareilly College, Bareilly–243 001 (U.P.) India.
Rapid industrialization is the need of the present time. It, in fact, produces a large amount of water, soil and air pollutants. The release of industrial effluents, pesticides and fungicides may also lead to heavy metal toxicity in environment. These heavy metals not only cause health hazards to man but also induce mutations in plants. Two heavy metals viz. Lead and Zinc were tested by using Allium cepa in relation to its chromosomal behavior in the form of aqueous solution of lead acetate and zinc sulphate. These heavy metals showed stimulatory effect on mitotic index at lower concentrations (100 ppm and 250 ppm), while at higher concentrations (500 ppm, 750 ppm and 1000 ppm) showed inhibitory effect on mitotic index. Several chromosomal aberrations were observed like: Chromatid separation, chromosomal breakage, scattering, stickiness, extrusion, bridge, polarity abolition etc. The mitotic index, frequency of aberrations and their percentage as induced by these heavy metals were also calculated in accordance with the methods of Singh (1991). The investigation indicated that these heavy metals have mitodepressive potentiality and were hazardous to cell cycle in Allium cepa.