In vitro activity of Purpureocillium lilacinum isolates against phytopathogenic fungi of sorghum

HOURS, R.A.; GORTARI, M.C.; ASTORECA, A.

Avanços Científicos e Tecnológicos nas Ciências Agrárias

Atena

Lugar: Ponta Grossa; Año: 2020; p. 62 - 75

Sorghum is the fifth cereal in importance worldwide. Its productivity is threatened by phytopathogenic fungi that reduce crop yields. Many species of Alternaria are natural contaminants of sorghum. The period of storage of those grains is a critical point to fungal control. Currently, there is an attempt to reduce the use of agrochemicals and to apply alternative control strategies such as biopesticides. In this context, the objective was to evaluate the in vitro antifungal activity of Purpureocillium lilacinum on the growth of Alternaria. Dual cultures of this specie were performed against potentially antagonistic isolates. The macro and microscopic evaluation was performed and five antagonism indicators were calculated. The interaction mechanisms involved were also determined by evaluating the effect of volatile and non-volatile metabolites produced by antagonist on the growth of phytopathogens fungus. The three P. lilacinum isolates had variable inhibitory activity according to the type of assay and phytopathogen evaluated. However, the inhibition was more evident with P. lilacinum Ls isolate and mainly with the effect of the non-volatile compounds. This study suggests that P. lilacinum could be considered a promising antagonist in the control of Alternaria. These results motivate us to go deeper in the production, isolation and identification of the compounds produced by this specie. The studied P. lilacinum Ls isolate could be another tool in the different biological control strategies applied to the conservation of sorghum grains.