The insecticide spirotetramat may induce cytotoxic and genotoxic effects on meristematic cells of <i>Allium cepa</i> L. and <i>Vicia faba</i> L.

Abstract

Spirotetramat (SPT) is a new insecticide derivative of tetronic acid used extensively in agriculture to enhance the protection of major food crops against scales and aphids. This study aims to determine SPT’s cytotoxic and genotoxic effects using two model plants, Allium cepa and Vicia faba. This evaluation consists of studying the root growth, morphology, and color and the parameters of mitotic index (MI) and chromosome aberrations (CAs) as accurate toxicity markers. Our results showed a significant decrease in mean root length in A. cepa from the 0.0025% concentration. In contrast, a substantial reduction in mean root length in V. faba was recorded only at the 0.02% concentration. Furthermore, the MI was decreased proportionally with increasing concentration and time of exposure to SPT. A significant increase in CAs was observed in A. cepa and V. faba from the 0.0025% concentration after 24 h of treatment. The substantial reduction in MI and abundance of CAs indicated strong genotoxicity of SPT. From the data obtained, it can be concluded that SPT could be absorbed by the exposed plant or other non-target organisms in the proximity, causing damage to agricultural plants, affecting their genomes, and harming the environment.