Clonostachys rosea BAFC3874 as a Sclerotinia sclerotiorum antagonist: mechanisms involved and potential as a biocontrol agent

M. ALEJANDRA RODRÍGUEZ; CABRERA GABRIELA M.; GOZZO FABIO; MARCOS N. EBERLIN; A. GODEAS

JOURNAL OF APPLIED MICROBIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2011 p. 1177 - 1186

1364-5072

Aims: The objective of this study was to establish the main mechanism of action of the antagonistic strain L32 of Clonostachys rosea against Sclerotinia sclerotiorum and to evaluate and determine its potential as a biocontrol agent. Methods and Results: The antagonistic activity of Clonostachys rosea L32 was determined in vitro by dual cultures and the strain proved to be an effective antagonist in lettuce and soybean crops against S. sclerotiorum. Antifungal activity assays related to the growth curve of C. rosea L32 established that the strain produced compounds associated with secondary metabolism. The high percentage of growth inhibition was observed in the peak of activity associated with an important inhibition in the sclerotia production. The isolation of the mixtures of substances with antifungal activity allowed us to establish that the antagonistic effect is given mainly by the production of antifungal metabolites. The strain produces a microheterogeneous mixture of peptides with a novel linear sequence, belonging to the family of peptaibiotics. Conclusions: C. rosea strain L32 proved to be an effective antagonist in greenhouse experiments against the aggressive soil-borne pathogen S. sclerotiorum. The main mechanisms involved production of metabolite from peptaibiotics families and in less degree mycoparasitism activity. Significance and Impact of Study: C. rosea L32 may be a good fungal biological control agent for S. sclerotiorum. Also this work provides the isolation and identification of peptaibol from very rare genera.