First detection of fungus Fusarium coffeatum in the territory of the Russian Federation

According to the data of Rosstat, сereals and pulses took 17.2-20.2 % of agricultural production in Russia in 2014-2018, and their gross harvest in the same period was from 105.2 to 135.5 million tons. At the same time, the problem of contamination of grain and grain products by plant pathogens of different nature, including toxigenic Fusarium fungi, is still actual. Estimation of composition of species, affecting agricultural crops in different regions, is one on the key measures against Fusarium -induced infections spread. A complex investigation, which includes both traditional microbiological procedures and analysis of nucleotide sequences of marker genes followed by their comparison with reference ones from GenBank database, has been widely used for species-specific identification. This work is devoted to the description of the fungus of the genus Fusarium strain ION-3/4, isolated from wheat grain in Tula region of the Russian Federation (2014). DNA extraction and purification were performed by DNAeasy® Plant Pro Kit (Qiagen, Germany). Sanger sequencing of marker fragments of translation elongation factor 1 alpha ( TEF1a , fragment size 587 b.p.) and RNA polymerase II subunit gene ( RPB2 , fragment size 689 b.p.) was carried out on an automated sequencer ABI PRISM 3730 (Applied Biosystems, USA). To analyze TEF1a and RPB2 sequences, BLAST algorithm was used (https://blast.ncbi.nlm.nih.gov/Blast.cgi). Phylogenetic analysis and phylogenetic tree constructions were performed by MEGA-X software (https://www.megasoftware.net/) using maximum likelihood method and Kimura two-parameter model. Macromorphological characteristics of the isolate were studied on several culture media, micromorphology was studied using an Olympus CX33 microscope (Olympus Corporation, Japan). Complex of the results made it possible to identify the isolate - strain ION-3/4 as recently described Fusarium coffeatum species, belonging to the F. incarnatum-equiseti species complex. Phylogenetically the isolate (strain ION-3/4) formed a separate group with ex-type F. coffeatum strain 635.76. Key morphological characters (mycelium type, conidia shape and size, structure of mono- and polyphialides) also corresponded to the typical features of this species. As F. coffeatum is a member of F. incarnatum-equiseti species complex, which includes plant pathogens and mycotoxin producers, this species also can be considered as a potential cause of plant diseases and needs serious attention and further investigations.