Morphoanatomical responses of Bowdichia virgilioides (Fabaceae) to glyphosate drift in Brazilian cerrado agroecosystem

Abstract

This study evaluated the morphoanatomical responses of Bowdichia virgilioides (Fabaceae) under glyphosate drift in an agroecosystem in the Brazilian Cerrado. Two leaf collections were carried out for ten individuals from two areas: border area (BA) and control area (CA). Visual symptoms were evaluated with leaf injury (LII) and severity (SI) indices, the anatomical through the use of usual anatomy techniques and the micromorphometric through the Anati Quanti software. Chlorosis and necrosis were found. The IIFs and ISs were higher for BA leaves and may be due to impacts that occur at the management edge of the agricultural area. Rounded chloroplasts, cell plasmolysis, hyperplasia, cell proliferation and collapse, symptoms similar to those found in glyphosate drift simulation studies, were noted. The thicknesses of the palisade parenchyma and, consequently, of the mesophyll differed significantly between collections, in BA, and between individuals in CA and BA, in the May 2017 collection. Factors such as higher solar incidence in plants of BA, probable occurrence of other sprays, as well as a longer period of exposure and the action of contaminants on the leaves of the second collection explain these changes. In the field, visual, anatomical and morphometric evaluations of leaf symptoms were suggestive of pesticide drift.