EVALUATION OF THE TOXICITY AND APOPTOTIC EFFECTS OF SUBLETHAL CONCENTRATION OF THE PLANT GROWTH REGULATOR (ESREL) ON THE SLUG “DEROCERAS RETICULATUM”

Abstract

Slugs are serious pests of horticulture and agricultural crops. Beside the ability of some plant growth regulators to regulate the growth of cultivated plants, they have Eco-toxicological effects on some invertebrates. So the present study was performed to evaluate the biological toxicity of sublethal concentrations (200 and 400 µl/l) of the plant growth regulator (PGR), Esrel (48% Ethephon), on Deroceras reticulatum after 2 weeks of exposure. The LC50 and LC90 were 980 and1500 µl/l, respectively. The obtained results indicated that PGR treatment led to a significant decrease in growth rate (P≤0.05), by the end of experiment it was 1.5 ± 0.03 g, 1.3 ± 0.04 g at the concentrations 200, and 400 µl/l, respectively compared to control (2 ± 0.03 g). In addition, flow cytometric analysis of cell cycle and immunohistochemical assays recorded DNA damage in digestive gland cells of D. reticulatum. The percentage of apoptosis was 78% and 93% at the concentration 200 and 400 µl/l, respectively, compared with control (8%). The study concluded that Esrel has toxic and apoptotic effects on D. reticulatum, so it has been proposed that the Esrel can be used as a molluscicide for the slug, Deroceras reticulatum.