Interactions between Three Fungi Associated with Esca of Grapevine, and Their Secondary Metabolites

Abstract

The effect of the culture filtrates, crude organic extracts of culture filtrates, metabolites such as scytalone,
pullulan and oligosaccharides produced by three fungi associated with esca, Phaeomoniella chlamydospora (Pch),
Phaeoacremonium aleophilum (Pal) and Fomitiporia punctata (Fop), on the growth of the fungi themselves, was
studied in vitro. At 1:1 dilution, the culture filtrates of Pal and Pch inhibited Fop completely, whereas at 1:2 dilution
they only increased Fop growth latency. Fop was not inhibited by crude organic extracts of Pal or Pch. Growth of Pal
was slightly stimulated at the lowest concentrations of Pch crude extracts, whereas it was inhibited at the highest
concentration. Scytalone (at 1 mg ml-1), pullulan (at 0.2 mg ml-1) and oligosaccharides up to 2.5 kDa (2 mg ml-1) did not
affect the radial growth of Fop.