POTENCIAL BIOINDICADOR DE Inga cylindrica (VELL.) MART. (LEGUMINOSAE, MIMOSOIDEAE) A CHUVA SIMULADA DE FLUORETO DE POTÁSSIO

Abstract

Currently, fluoride (F) is considered a major contributor to air and water pollution, which affects 200 million people worldwide. Being a toxic substance when ingested in high doses, it can present acute or chronic toxicity. Fluoride is commonly released into the environment by brick manufacturing activities, aluminum, glass and steel industries. Plants absorb F mainly through the leaves, and when sensitive they present symptoms that can be classified as environmental indicators. In this scenario, the objective of this work was to investigate the effects of fluoride, via simulated rainfall with potassium fluoride, on Inga cylindrica leaves, in order to evaluate the potential bioindicator of the species. The experiment was conducted in a greenhouse, the plants were exposed to the application of a liquid solution of potassium fluoride (KF, pH 6.0) at concentrations of 0, 10, 20 and 30 mg L-1 for 60 consecutive days, simulating the concentration of fluoride found in precipitation in polluted areas. After dismantling the experiment, visual, morphoanatomical and micromorphometric evaluations were carried out on the leaves. From these analyses, it was observed formation of chlorosis and necrosis at doses of 20 and 30 mg L-1 in I. cylindrica, showed alteration in the palisade parenchyma at the highest dose tested, accumulation of phenolic compounds, growth of 13% of the palisade parenchyma in the concertation of 10 mg L-1 compared to the control. With this study, we can conclude that Inga cylindrica has biosensor potential at doses of 20 and 30 mg L-1, having potential for environmental monitoring.