Mecanismos morfofisiológicos de tolerância de Borreria densiflora ao glyphosate

Abstract

Weed tolerance to herbicides is a phenomenon caused by different factors, be they morphological, anatomical, physiological and biochemical. Knowing the mechanism that makes plants tolerant to herbicides is crucial for developing more efficient control strategies. Thus, we start from the hypothesis that changes in anatomical characteristics and cuticular wax throughout the phenological stages of Borreria densiflora DC. play a crucial role in the absorption and metabolization of the herbicide glyphosate. The experiment was conducted in a greenhouse in a completely randomized experimental design, in a factorial scheme 4x2x3+1. The first factor consisted of the application of glyphosate in four phenological stages of B. densiflora DC. The second factor was two doses of glyphosate. The third was the time of leaf collection after the application of herbicides. Furthermore, an additional control without glyphsoate application was added. The variables evaluated were: leaf and epidermis thickness, amount of cuticular wax, chemical composition of the cuticular wax, control efficacy and the content of glyphosate and aminomethylphosphonic acid (AMPA) in the aerial part. The results show that the effectiveness of glyphosate varies with the phenological stage, being more pronounced in the initial stages of development. The metabolization of glyphosate, especially during flowering, suggests an adaptation of the plant to resist the herbicide. Changes in the composition of cuticular wax, including the presence of compounds such as decosane and 2,4-bis(1,1-dimethylethyl) phenol, are associated with lower absorption of glyphosate, revealing the direct influence of these components on the dynamics of the cuticular wax response. plant to herbicide. These findings contribute to an in-depth understanding of plant-herbicide interactions, providing a solid foundation for integrated and sustainable strategies in B. densiflora DC. control.