In vitro and In vivo Antifungal Activity of Culture Filtrates and Organic Extracts of Penicillium sp. and Gliocladium spp. against Botrytis cinerea

Abstract

Eight isolates of Penicillium sp. and two isolates of Gliocladium spp. were tested in vitro and in vivo for their inhibitory effects against Botrytis cinerea, causal agent of tomato fruit grey mold. The biocontrol essays conducted in vitro revealed that the culture filtrates of the isolates tested have significantly reduced the mycelial growth of the pathogen. The filtrates of the isolate CH6 of Penicillium sp. applied at different concentrations (10, 15 and 20% v/v), was most effective in reducing B. cinerea colony diameter. The ethyl acetate and chloroform extracts of the isolates CH6 of Penicillium sp., Gc1 of G. catenulatum and Gv1 of G. virens have shown an inhibitory effect of the pathogen radial growth, at the concentrations used (1, 2.5 and 5% v/v). In addition to the reduction of the mycelial growth of B. cinerea, these antagonistic agents have induced important morphological alterations to the mycelium of the pathogen. These antagonists were applied to tomato fruits 2 hours before their inoculation with the pathogen. Tested as culture filtrates, the most effective isolates CH11 and MC1 of Penicillium sp. and Gv1 of G. virens had significantly reduced the severity of the disease compared to the inoculated and untreated control fruits. Similar effects were recorded using the ethyl acetate and chloroform extracts of the tested antagonists; those of CH6 and CH5 of Penicillium sp. and Gc1 of G. catenulatum were found to be the most effective in reducing severity grey mold. Thus, this study showed the presence of bioactive molecules in the culture filtrates of the antagonistic agents used and also allowed the selection of effective isolates for grey mold disease control.