Cytogenetic effects of kernel extracts from Melia azedarach L.

Cytogenetic effects of kernel extracts, which contain azadirachtin as the active insect antifeedant and growth regulator, were evaluated in the root meristem cells of Allium cepa. The test concentrations were determined in accord with the recommended dosages in agricultural applications. Each test concentration of the kernel extract significantly reduced the mitotic index (MI) and induced chromosomal aberrations and mitotic aberrations. The kernel extracts induced breaks, bridges, stickiness, pole deviation and micronuclei in aberrant cells. Furthermore, the effect was directly related to the concentration of the neem extract. These observations showes that the kernel extracts prepared from this plant are harmful for crops and for non-target organism.