Detection of mycotoxigenic Fusarium species and mycotoxins in different malting barley varieties.

A study was carried out in order to evaluate the presence of mycotoxigenic Fusarium spp. associated to Fusarium Head Blight (FHB) and mycotoxin contamination in 15 malting barley varieties harvested at the Experimental Station of the Faculty of Agriculture of Perugia (Papiano, Umbria, central Italy) in 2012. Grain samples were subjected to fungal isolation and to the determination of the infecting fungal species. The isolates belonging to the Fusarium genus were identified by species-specific PCR or by sequencing the TEF1α gene. Fungal genotype characterization by tri5 (trichothecene producers), tri12 (trichothecene chemotypes NIV, 3ADON or 15ADON producers) and esyn1 (enniatin producers) gene amplification, was realized to determine the mycotoxigenic potential of the isolated strains. Quantification of the mycotoxins DON and T-2 present in the kernels was also performed by the ELISA method. Anthesis time and weather data were collected to detect the possible presence of favourable conditions to FHB. In the surveyed year, unfavourable for the development of FHB, the incidence of fungal infections was 21% for Fusarium spp., 30% for Aspergillus spp., 28% for Alternaria spp. and 17% for Penicillum spp.. The most frequently detected species were F. tricinctum followed by F. proliferatum, F. graminearum and F. avenaceum. F. graminearum strains were potential trichothecene producers and belonged to the NIV chemotype. F. tricinctum and F. avenaceum were all potential enniatin producers. The average DON concentration did not exceed the EU legal limits. The average T-2 toxin contamination was critical if compared to the level recently recommended by the EU (2013/165).