CITRULLUS COLOCYNTHIS AND CALOTROPIS PROCERA AS SOURCE OF ANTIFUNGAL AGENTS AGAINST FUSARIUM OXYSPORUM F. SP. ALBEDINIS

Abstract

In the present study, two poisonous plants from the Algerian Sahara (South-West of Algeria): Citrullus colocynhis (L.) Schrad and Calotropis procera Ait., were used to evaluate their extracts for antifungal activity against Fusarium oxysporum f. sp. albedinis (Foa), the causal agent of the most dangerous disease of date palm (Phoenix dactylifera L.). Two parts from each plant were used for extraction by four solvents: methanol, ethyl acetate, dichloromethane and hexane. The antifungal test was realized using disc diffusion technique and relative virulence (RV) test (on potato tuber tissue). For both tests, four extract quantities were used (200, 400, 800 and 1600g). The relative virulence was presented as necrotic tissue weight (mg) of potato tuber tissue. Among all solvents, methanol gave the best extraction yield (21.91%). The results of disc diffusion assay showed that the most important effect on Foa was observed for methanolic extracts of Citrullus colocynthis (leaves and stems). The virulence test showed a decrease in RV below 50% for methanolic and dichloromethanic extracts of Citrullus colocynthis (leaves and stems). Coupling the effect of plants extracts on Foa growth and virulence, Citrullus colocynthis extracts showed great efficacy than did the other plant.