Effect of Heavy Metal Cadmium on Cell Proliferation and Chromosomal Integrity in Allium cepa

Cadmium (Cd), one of the most toxic heavy metals, seriously impairs plant and animal physiology and is a potent mutagen. Effect of a cadmium salt on chromosome integrity was studied for increasing concentrations and for different exposure time in root tips of onion A. cepa. Cd had cytostatic effect in higher concentration (100 µM). It showed chromosome damage, which was most pronounced at 100 µM after 24 h. of exposure. Abnormal chromosome separation was also observed. It can be concluded that Cd can inhibit cell proliferation in higher concentration irrespective of exposure time. And it can introduce chromosomal damage in A. cepa even within 2 h. of exposure.