Foliar structural differences between glyphosate-resistant and glyphosate-susceptible biotypes of Digitaria insularis (L.) Fedde¹

ABSTRACT

Digitaria insularis (L.) Fedde stands out for its resistance to glyphosate and this characteristic may have a relationship with structural alterations. In such context, this research aimed at the characterization of the foliar anatomical structure of two populations of D. insularis (glyphosate-resistant and glyphosate-susceptible biotypes) collected in agricultural areas of Paraná, a Brazilian state. The experiment was conducted at the Laboratory of Botany of the Universidade Estadual do Oeste do Paraná – Unioeste, Brazil. The resistant biotypes of D. insularis differ from the susceptible ones in several structural parameters. Among them, the Mesophyll Thickness in the interveinal region was 7.3% thicker in the resistant biotype, which was also observed in the thickness of the keel, in the percentage of 11.3%, and in the thickness of cuticles in the adaxial surface (TC_ad), which was 53.8% thicker in the resistant biotype. In this way, we concluded that the resistant biotypes of D. insularis differ from the susceptible ones in several anatomical foliar characteristics, therefore, they present possible mechanisms of resistance to glyphosate.

Keywords
biology; leaf; sourgrass; thickness of cuticles; weed