Phytochemical and antifungal properties of gongronema Latifolium and Heinsia crinite. Leaf extracts against fungal pathogens associated with post-harvest rot of selected fruits

Abstract

Antifungal potentials of Gongronema latifolium and Heinsia crinita leaf extracts were evaluated against some fruit rot pathogens. Preliminary  phytochemical screening revealed among others the presence of alkaloids, flavonoids, saponins, tannins and cardiac glycoside at varying amounts in  both ethanolic and aqueous extracts of the plants. Inhibitory activities of the extracts against the mycelial growth and spore germination of an array of  fungi that cause fruit rots showed that their antifungal potentials were concentration dependent. Thus, at the highest extract concentrations of 750  mg/mL, highest inhibitions were observed and the least activities were obtained for concentration of 250 mg/mL extract. This is attributed to the  bioactive phytochemical constituents at different extract concentrations particularly the alkaloids and cardiac glycosides. The extracts of G. latifolium  leaves at highest concentrations of 750 mg/L proved highly effective, with zones of inhibition that ranged from 12.0 to 21.0 mm, for inhibiting spore  germination in all the test organisms except Talaromyces verruculosus and Candida utilis while that of H. crinita ranged from 12.0 to 20.0 mm and was able  to inhibit spore germination of all test organisms except Rhizopus oligosporus and Absidia corymbifera. Evidently, these plant extracts have great potential  as natural antifungals which can be safely used against post-harvest rot of fruits.