Antifungal evaluation of saponins extracted from quinoa husk (Chenopodium quinoa Willd) against Botrytis cinerea in strawberry

Abstract

Saponins are widely recognized for their biological properties, which has led to the development of several research projects applicable to the agricultural sector. In this sense, the aim of this study was to evaluate the in vitro and in vivo antifungal effect of saponins extracted from quinoa husks, using the crude extract, and incorporated in a formulation against Botrytis cinerea in strawberries. The extraction of saponins by the maceration method was studied, where the effect of temperature, time, and ethanol concentration on the extraction of saponins was evaluated; the process was optimized using a central composite design (CCD). The in vitro antifungal effect of the crude extract of saponins was evaluated by the minimum inhibitory concentration (MIC), while the in vitro and in vivo antifungal effect of the formulation was determined by the mycelial inhibition percentage and control percentage, respectively. The optimum extraction point of saponins was obtained at 49.8 °C, 0.367 h, and 47.4% ethanol. On the other hand, the antifungal activity against Botrytis cinerea was dependent on the concentration of saponins; in the in vitro evaluation the MIC of the crude extract was 8.25 mg mL-1 of saponins and the mycelial inhibition percentage of the formulation was higher than 90%. In the in vivo evaluation of the formulation, the percentage of control ranged from 63.03 to 76.14%, compared to 61.5% control exhibited by the chemical fungicide Carbendazim.