Fusarium graminearum sensu stricto and Fusarium poae isolated from different barley regions in Argentina and biocontrol in vitro, under field conditions and during the micromalting process

Abstract

Barley (Hordeum vulgare L.) is the second most important winter crop after wheat in Argentina, and is mainly used for the malt production in beer manufacture. Fusarium species, mainly Fusarium graminearum sensu stricto and F. poae, cause Fusarium Head Blight (FHB) in barley and produce reductions in quality and safety pre-harvest and during the malting process due to fungal growth and mycotoxin contamination. The aims of the present study were- to evaluate incidence of F. graminearum species complex and F. poae in different barley-growing regions from Argentina, to determine their toxigenic ability, to evaluate the biocontrol activity of B. velezensis RC218 to reduce F. graminearum ss and DON accumulation under field conditions and during micromalting process to select new potential biocontrol agents to control F. graminearum ss and F. poae growth under in vitro conditions. Data showed that F. graminearum ss was isolated with high incidence in all regions during 2016 and 2017 harvest seasons. The chemotype of the strains was DON-15ADON and DON-3ADON, also the strains were producers of ZEA and their derivatives. NX-2 chemotype was detected for the first time from strains isolated from barley in Argentina. Fusarium poae was isolated in two regions and were NIV producers, besides other toxins produced by the strains were DAS, NEO, MAS and T2-tetraol. The application of B. velezensis RC218 in vitro, under field conditions and during micromalting process showed reduction of F. graminearum ss fungal growth and DON accumulation. Some new potential biocontrol agents were selected such as Lactobacillus plantarum and B. subtillis subsp. inaquasorum.