Determinación de la actividad antifúngica de las saponinas de la quinua frente a los agentes causales del damping off ( Fusarium spp., Rhizoctonia sp., Pythium sp.), 2016.

Abstract

The objective was to determine the antifungal activity of quinoa saponins against damping off causal agents (Fusarium sp., Pythium sp. and Rhizoctonia sp.) for which pathogenic fungi were isolated in soil samples and potato tubers in growth medium, dextrose agar potato. The soxhlet method was used to obtain saponins from the hulls and the quinoa grain in aqueous and ethanolic extracts, they were extracted at concentrations of 100, 50, 25 and 12.5% V/V, respectively. The ethanolic and aqueous extract of the hulls and the quinoa grain were placed in growth media to observe its effect on the growth of fungi under study. The statistical analysis was bases on a completely randomized experimental design (CRD) with 4 treatments and three repetitions, by means of the Tukey test at 5%, the best treatment was determined. The results obtained demonstrate that the growth of fungi in the saponins from the ethanolic extract of the quinoa hulls presents a higher antifungal activity with 60 to 75% compared to Fusarium spp., for Pythium sp. and its inhibitory effects from 51 to 92%; while for Rhizoctonia sp. its inhibition reaches 94%. Aqueous extracts of the hulls and the quinoa grain stimulated the growth of the pathogens because of their chemical characteristics. It is recommended to test a different concentrations the percentage of ethanol used for the extraction of quinoa saponins (Chenopodium quinoa Will) in order to verify if the inhibitory activity is due to alcohol or saponins.