Potencial antimicrobiano de extratos etanólicos de folhas de sibipiruna (Caesalpinia peltophoroides) e breu branco (Protium heptaphyllum) em fitopatógenos

• Autor(a) principal: Lima, Airton
• Data de Publicação: 2016
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFMT
• Texto Completo: http://ri.ufmt.br/handle/1/2117
• topic: Agrotóxicos; Medidas alternativas; Compostos bioativos; Atividade antifúngica; CNPQ::OUTROS::CIENCIAS; Agrochemicals; Alternative measures; Bioactive compounds; Antifungal activity

The Brazilian biodiversity has been studied by several researches that are looking for determine the effect of plant extracts against plant pathogens, as an alternative to the use of chemicals products. Face to this, the present research aimed to study part of the brasilian flora in order to verify the effect of extracts of sibipiruna leaves (Caesalpinia peltophoroides) in three Colletotrichum sp using two methodologies: evaluate the fungitoxic effect of different extracts concentrations of C. peltophoroides and white pitch (Protium heptaphyllum) against Colletotrichum truncatum, Colletotrichum sp., Fusarium equiseti, F. prolifetarum and F. solani. First, tests were performed with plant pathogens Colletotrichum sp. and C. truncatum isolated of soy beans from three different locations, through the methods of disk diffusion and spreading. It was used the ethereal fraction of leaves of C. peltophoroides and ethanolic extract of leaves of P. heptaphyllum against isolates of C. truncatum, Colletotrichum sp., F. equiseti, F. solani and F. prolifetarum tested in various concentrations for disk diffusion method. It was found the percentages in inhibition of mycelial growth, mycelial growth rate index, inhibition of sporulation, germination, and training appressoria. The ethanolic extract from the leaves of C. peltophoroides shows antifungal activity against three kinds of Colletotrichum, it was observed that the reduced speed of mycelial growth, which was similar to the fungicide. Inhibit sporulation, in some concentrations, above 60%; and the appressorium formation to 92.30%, proving to be effective. The methodology scattering when compared to disk diffusion showed better results for the evaluation of antifungal activity in the inhibition of sporulation. The C. peltophoroides extract was effective in all tested variables, with satisfactory results in at least one of the isolated and evaluated species. The C. peltophoroides extract has antifungal activity and can be an efficient and environmentally friendly alternative for the control of plant pathogens. The P. heptaphyllum extract did not inhibit mycelial growth and sporulation of the evaluated plant pathogens; however, inhibit the germination and the formation of appressoria, especially species of Fusarium. From the results obtained in this study, one can conclude that the ethanolic extracts of leaves of C. peltophoroides and P. heptaphyllum have antimicrobial potential on some of the variables tested. Therefore, further studies should be performed to confirm the in vivo bioactivity of antifungal in vivo species of C. peltophoroides and P. heptaphyllum and identify specific bioactive compounds and their mode of action, so that they can eventually be used as an alternative to fungicides.