. Concentration– response Curve of the strobilurin fungicide azoxystribin in the aquatic macrophyte Myriophyllum quitense.

GARANZINI, D, MENONE, M.

Berlin

Congreso; 6th SETAC World Congress / SETAC Europe 22nd Annual Meeting; 2012

SETAC Europe Office

Strobilurin fungicides constitute a relatively new fungicide class developed from natural fungicidal derivatives and the great impact of them on agriculture is reflected by the widespread use of azoxystrobin (AZX), a compound approved for use on almost 100 different crops. Its mechanism of toxicity is well understood in fungi but it effects in plants is scarcely studied. Aquatic macrophytes have been used as environmental biomonitors because of its bioacumulation capacity of xenobiotics. The main goal of this study was to establish a concentration- response curve of AZX in Myriophyllum quitense, by using oxidative stress enzyme activities and chlorophyll content. Particularly, the activity of Guaiacol Peroxidase (POD), Glutathione- S –Transferase (GST), Catalase (CAT), and the chlorophyll a and b contents were tested.. Plants were exposed to 0 (negative control); 0,1; 1; 10; 50 and 100 ug /L of AZX for 24 hours. All the parameters were measured espectrophotometrically. Inhibition of CAT and POD at 50 ug/L was observed (p0.05). Although there was no change in the chlorophyll a/chlorophyll b ratio among treatments an increased content of both pigments at 100 ug/L with respect to control was observed (p