Effect of the fungicide trifloxystrobin on B-esterases activity in tadpoles of Scinax nasicus (Amphibia: Anura

ATTADEMO, A.M., .; JUNGES, C.M.,; LAJMANOVICH, R.C., ; PELTZER. P.M., ; CABAGNA-ZENKLUSEN. M., ; LORENZATTI, E.A

San Juan

Jornada; 2da. Reunión Conjunta de las Sociedades de Biología de la República Argentina; 2011

SAIC

Normal021falsefalsefalse st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {msostyle- name:"Tabla normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-marginbottom:. 0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansilanguage:# 0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} In our country, in late 2007, new strobirulin and triazole based biocide formulations were introduced to the market. These components ensure high control of new fungal late season diseases in soybean crops. Trifloxystrobin (TFT), one of these formulations, is characterized by being very toxic to aquatic organisms, with a half-life of 8-24 hours in surface waters. The aim of the present work was to evaluate the effect of TFT on B-esterasase activity (butyrylcholinesterase; BChE and acetylcholinesterase; AChE) on tadpoles of Scinax nasicus (Amphibia: Anura) under controlled laboratory conditions. Acute toxicity bioassays (24 and 48 h) were performed using sublethal concentrations of TFT (0.0312, 0.0625, 0.125, and 0.250 mg/L) and a control, with the respective replicates. The commercial product used was Flynt® (50% a.i., Bayer CropScience S.A., Argentina). Seven larvae, Gosner stage 39-42, per container and per treatment were exposed under a light-dark (12:12) photoperiod at 25 ± 2°C. Muscle BChE and brain AChE activities were determined for each individual using routine techniques. The results obtained indicate an inhibition of BChE activity at all TFT concentrations assayed (P< 0.05) at 48 h of exposure with respect to control. A similar trend was observed for AChE, but no statistically significant differences were observed (P > 0.05). We preliminary determined an inhibitory effect of TFT on BChE activity of S. nasicus tadpoles.® (50% a.i., Bayer CropScience S.A., Argentina). Seven larvae, Gosner stage 39-42, per container and per treatment were exposed under a light-dark (12:12) photoperiod at 25 ± 2°C. Muscle BChE and brain AChE activities were determined for each individual using routine techniques. The results obtained indicate an inhibition of BChE activity at all TFT concentrations assayed (P< 0.05) at 48 h of exposure with respect to control. A similar trend was observed for AChE, but no statistically significant differences were observed (P > 0.05). We preliminary determined an inhibitory effect of TFT on BChE activity of S. nasicus tadpoles.