In vitro effects of Trichoderma secondary metabolites on Phaeoacremonium aleophilum

Trichoderma species have an important relevance as biocontrol or biological agents inhibiting phytopathogenic fungi growth. Some of the secondary metabolites Trichoderma produces have shown antifungal activity. Phaeoacremonium aleophilum has been described as one of the first fungi colonizers which cause the Grapevine Trunk Disease.

The aim of this study is to evaluate the efficiency of an array of trichoderma species mainly isolated from old vineyards in controlling this important grapevine wood pathogen.

This in vitro antifungal experiment was carried out using a celophane membrane over PDA growth medium. The membrane allows secondary metabolites to pass through whereas fungi mycelium is retained¹.

Results show (Figure 1) T100 to be the strain with the highest inhibitory capacity percentage, being well over 50%. The following group of strains in the ranking, T077, T075, T084, T115, T127, T120, T080 and T074 exhibit a capacity between 30 and 40%. Finally, the strains coming after this group continue in a decreasing succession reaching an inhibitory capacity less than 10%.

Fig. 1: Isolated Trichoderma strains with inhibitory capacity against P. aleophilum. Error bars are depicted. Different letters show significant differences. (Fisher's LSD. p < 0.05).

Pathogen growth is decreased by trichoderma secondary metabolites, stronly depending on trichoderma strain. Further trials are needed to identify the most efficient trichoderma strains at controlling Phaeoacremonium aleophilum.

[1]. Mayo, S, S. Gutiérrez, M.G. Malmierca, A. Lorenzana, M.P. Campelo, R. Hermosa, and P.A. Casquero. 2015. Front. Plant Sci. 6: 1 – 11.