Extrato padronizado de Rosmarinus officinalis L. (Lamiaceae) na supressão da brusone foliar em arroz

• Autor(a) principal: Garcia, Mythali Lima
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/00130000029jb
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5379
• topic: Indução de resistência; Manejo integrado; Ácido rosmarínico; Alecrim; Oryzae sativa; Magnaporthe oryzae; Induction of resistance; Integrated management; Rosmarinic acid; Rosemary; Oryzae sativa; Magnaporthe oryzae; CIENCIAS DA SAUDE::FARMACIA

The blast caused by the fungus Magnaporthe oryzae, is a disease affecting rice significantly throughout the world. Seeking its control, fungicides have been used indiscriminately. With the need to develop alternative control methods, the uses of plant extracts have been a promising strategy for the control of phytopathogens. The objective of this study was to develop and characterize the liquid extract of Rosmarinus officinalis standardized in rosmarinic acid and evaluate its potential as resistance inducer and suppressor of leaf blast on rice crops. The standardization was initiated by characterization of plant material followed by obtaining the liquid extract by percolation method. The liquid extract was characterized as pH, viscosity, density, solids content and chromatographic profile for Thin Layer Chromatography. A method by high-performance liquid chromatography to quantify the rosmarinic acid in the liquid extract was validated. In Embrapa Rice and beans, rice seeds were sown and three concentrations of R. officinalis extract and standard of rosmarinic acid were sprayed and monitored in plants to test their respective capabilities suppression of leaf blast and inducing resistance in rice from increase enzyme activity of chitinase, β-1,3 glucanase, peroxidase, lipoxygenase, phenylalanine ammonia lyase, of phenolic compounds and salicylic acid hormone, before and after challenge with M. oryzae. All treatments reduced the severity of leaf blast in rice in more than 80%. In the absence of the pathogen from four hours, all treatments increased the expression of enzymes related to the defense of the plant, the phenolic compounds and salicylic acid hormone, except for the peroxidase. In the presence of M. oryzae, the enzymatic activity of GLU, CHI, POX, LOX, PAL, phenolic compounds and salicylic acid content increased significantly. The standardized rosemary extract in rosmarinic acid has proven to be a powerful alternative method for controlling the blast in rice and may be associated with integrated management techniques.