Efectivity of Phosphine on The Growth of Storage Fungi In Vitro

Abstract

Studies on the effectivity of phosphine on the growth of six species of storage fungi (Aspergillus candidus, A. flavus, A. niger, A. tanzarii, Eurotium chevalieri and Benicillium citrinum) have been carried out in vitro. Prior to fumigation, E. chevalieri was grown on Czapek Yeast Extract Agar containing 20% sucrose in a polyethylene Petri dish, and then incubated under laboratory conditions for 3 days, while other eleven fungal species were grown on Potato Dextrose Agar for two days. Before each fungal culture was placed in a glass jar (volume 3.3 I), the cover of the Petri dish was replaced with a piece of sterile rnusline cloth. After that the glass jar was tightly closed, in between the container and the cover of the jar was enlayered with plasticine. The fungal cultures were then fumigated with phosphine. Four oncentrations of phosphine were used, i.e. 0.5, 1.5, 2.5 and 3.5 mg/l. As control, each fungal spedies was not treated with phosphine. Three replications were used for each treatment (including control). The jars were incubated under laboratory conditions for five days. The results indicated that phosphine inhibited the 'growth of all fungal species tested. The percentages of inhibitions depended on phosphine concentrations and the fungal species. The percentages of inhibitions increased with the increase of phosphine concentrations. At 3.5 mg/l phosphine, the highest percentage of inhibition was observed on A. niger followed by A. flavtds, A. candidus, E. chevalieri, A. tamarii and P.citrinum.