Efficacy of extracts of some plants in avoiding fungal diseases of stored cereals

Abstract

Objective: Plant metabolites and plant-based pesticides appear to be one of the better alternatives to synthetic pesticides. The aim of the current study is to evaluate the antifungal properties of the aqueous, ethanolic, methanolic and chloroform extracts of the leaves and stems of five wild plants (Astrachantha echinus; Seriphidium herba-album; Peganum harmala; Diplotaxis acris and Tamarix aphylla) collected from Tabuk deserts of KSA, against seed-borne mycoflora isolated from stored corn, wheat and barley grains. Methods: In vitro antifungal activities of the 5 extracts were tested using the poisoned food technique. Separation of the different fractions from selected extracts was carried out using Thin Layer Chromatography (TLC). High Performance Liquid Chromatography (HPLC) was used to characterize the separated fractions and estimate the in vivo reduction in mycotoxins levels due to plants extracts. Results: Most of these extracts significantly suppressed radial growth of the tested fungi in vitro with varying levels and/or caused their complete inhibition (100%, P ≤ 0.01). Results of separation of selected extracts using TLC, and then their characterization by HPLC analysis revealed that these promising extracts were rich in p-Coumaric acid, Catechin, Caffeic acid, Cinnamic acid, Ferulic acid, Vanillic acid and Gallic acid in concentrations ranging from 97.0 µg/ml (Vanillic acid) to 471.1 μg/ml (Gallic acid). In addition, methanolic, ethanolic extracts of Astrachantha echinus and Seriphidium herba-album plants showed potent in vivo antimycotoxigenic activity (P ≤ 0.01) against toxigenic isolates of Apergillus flavus and Fusarium verticillioides in comparison with the synthetic fungicide. Conclusion: These novel methanolic, ethanolic extracts of Astrachantha echinus and Seriphidium herba-album plants could be commercially used as worldwide biodegradable and ecofriendly phytofungicides to prevent fungal biodeterioration of cereals; prevent mycotoxins production.