Microalgas Desmodesmus quadricauda e Monorraphydium sp. (Chlorophyta) oriundas do rio do leão, testadas como bioindicadores na detecção de glifosato

Abstract

Water microalgae are organisms with a wide diversity of survival forms, functions and strategies. Chlorophyta, phylogenetically linked to terrestrial plants and the aquatic environment, are one of the main producers in the food chain, and due to the rapid cycle, can be used as bioindicators of water quality.Aiming to test algae as bioindicators in glyphosate detection , phytoplankton and ficoperifiton samples were collected at the Leão river water collection station, Laranjeiras do Sul, Paraná. After collection, the algae were minimally identified in the Limnology Laboratory of the Federal University of the Southern Frontier campus Laranjeiras do Sul. Two taxa Desmodesmus quadricauda (Tur.) Bréb were used for the experiment . in Bréb . & God ., Monorraphydium sp . were considered acclimated when the sample showed a dark green. These species were submitted to four treatments: T1 = 125µm / ml (maximum allowed by legislation of 500µm / liter), T2 = 62.5 µm / ml, T3 = 12.5 µm / ml and T4 = 0 (control, without addition). of glyphosate ). Counts were conducted after two, four, 16, 24 and 96 hours after addition of the glyphosate commercial order to verify the behavior of the two taxa as the growth rate (number of individuals) population, cell activity, Pyrenoid morphology and cell . Density data showed that in control (T4) both species maintained their growth rates, while T1, T2 and T3 treatments decreased the number of individuals. However, only in 16 hours after the addition of glyphosate was detected the mortality of the species. Anova was used to treat the data , and it was possible to verify that there was a significant difference between the control and treatments. However, between treatments T1, T2 and T3 the behavior of the two species were similar. Regarding algal responses to treatments, Monorraphydium sp . responded better to treatments, becoming more evident the differences between control and treatments, not only by the density presented but also by the morphological aspect, which indicates the possibility to be a bioindicator.