In vitro antagonism of Clonostachys sp. against disease associated fungi in economically important crops

Abstract

Objectives/Background. The objective of this work was to evaluate the in vitro antagonistic capacity of a strain of Clonostachys sp. against five species of fungi associated with diseases in economically important crops. Materials and Methods. Five fungal species associated with crop diseases were tested: Alternaria alternata, Colletotrichum kahawae, C. musae, Fusarium oxysporum and F. solani. Dual cultures were performed with five replicates plus controls. Growth was recorded every 24 hours, until 360 hours were completed. Interactions were determined, the degree of antagonism and the percentage of colonization was calculated. Statistical analyses were performed with a generalized linear model (GLM). Results. All species evaluated showed antagonism of the overgrowth type. The degree of antagonism was classified into three classes, with class two being present in three of the species. The percentage of colonization was 100% at 216 h for three of the species and 264 h for the other two. There was no significant difference in the percentage of colonization (p =0.0073), but there was a significant difference in the time of invasion (p< 0.0001). Conclusion. Dual assays to test the antagonistic effect in vitro form the basis for the selection of candidates for biological control of fungi.