IN VITRO ANTIFUNGAL ACTIVITY OF SWINGLEA GLUTINOSA LEAF EXTRACT AGAINST COLLETOTRICHUM GLOEOSPORIOIDES ON PERSEA AMERICANA MILL

Abstract

The avocado (Persea americana Mill.) is a species whose cultivation is of great nutritional and economic importance for the Maria mounts region, the variety of avocado grown is the Antillean race and var. lorena; however, like any other crop, it is often affected by pests and diseases that limit its commercialization at national and world level. The phytopathogenic fungus Colletotrichum gloeosporioides is the causal agent of anthracnose in avocado and manifests itself in the early stages of fruit development, as well as in postharvest and during storage, under conditions of high relative humidity (80%) and temperatures from 20 ◦C. Economic losses due to this fungus can be up to 20% of production.   Therefore, the objective of this work was to evaluate the antifungal activity of extracts and fractions of Swinglea glutinosa against Colletotrichum gloeosporioides, in avocado crop The plant material used corresponded to dried leaves of S. glutinosa collected in two agroecological regions of the department of Sucre, Colombia. The collected plant material was used to obtain ethanolic extracts. Three chromatographic fractions were obtained from the extracts and four concentrations (1%, 25%, 50% and 75%) were prepared per municipality. Each concentration was used for In vitro evaluation against C. gloeosporioides. The results obtained show that at a concentration of 75%, the highest percentages of antifungal index (% A.I.) were obtained for the bioproduct fraction 2 and extract from the municipality of Sincelejo with a % A.I. of 96.6% and 87.2%, respectively.  In this study, both extracts and fractions 2 showed 100% inhibition in the germination of C. gloeosporioides conidia at a concentration of 25%. The chromatographic profile of the bioproducts found evidenced the presence of terpenoid compounds, in which antimicrobial activity has been demonstrated.