ABSTRACT
Several toxigenic Fusarium species are involved in Fusarium head blight which reduces both, crop yield and quality of cereals. Fusarium species have also caused several outbreaks in cereal-producing areas. Traditionally, Fusarium isolates have been grouped to species and sections according to their morphological and cultural characteristics. But now researchers have started to use molecular data and phylogenetic analyses for classifying the Fusaria, because often it is not possible to recognize new phylogenetic species by morphological characters. Therefore, the best way to identify and classify the isolates of Fusaria is now the polyphasic approach by using all available characters. Trichothecene-producing Fusarium species form a well-supported clade which is closely related to the F. avenaceum/F. art hrosporioides/F. tricinctum/F. acuminatum/ F. torulosum species complex that does not produce trichothecenes. Within the trichothecene-producing clade, the most important species in northern Europe and Asia belong to the deoxynivalenol (DON)— producing F. graminearum species complex and to the T-2/HT-2-toxin producing F. sporotrichioides-F. langsethiae species complex. New DON— (F. ussurianum and F. vorosii) and T-2/HT-2 toxin-producing (F. langsethiae and F. sibiricum) Fusarium species have been found recently in northern Europe and Asia. F. langsethiae is mainly distributed in Europe, while F. sibiricum is distributed in Siberia and Russian Far East with two single isolates from Norway and Iran. So, it is probable that the actual distribution of E. sibiricum will be much larger than the present known distribution.
