Fly-ash induced chromosomal aberrations in Allium cepa

Abstract

Fly-ash released from coal-based power plants contains heavy metals which cause genetic damage to, or death of, plants. For genetic investigation onion bulbs were grown in fly-ash polluted soils, collected around such a power plant. Root growth was checked in all soil samples after 72 h when their tips were turning brown or black. Mitotic and chromosomal anomalies, viz clumping stickimetaphase, laggards, chromatin bridges and fragments were encountered. Abnormalities were more numerous nearer the source of the pollution. Fragments and c-mitosis appeared but in lower numbers due to heavy metal inhibition of spindle fibres. Deposition of fly-ash contaminates the soil, upsets equilibrium of the ecosystem, and causes genetic damage to flora in and around power plants.