Hrytsev O. Etiology and diagnostics of fungal cereal infections on the territory of Ukraine

Cereals are of strategic importance for Ukraine and occupy more than half of the sown area among all crops. Large sown areas do not allow for rational crop rotations. It leads to the accumulation of pathogens and increase the range of their harmfulness. In terms of grain yield, Ukraine is inferior to other leading exporting countries in the world. Among the factors which negatively affect the realization of the genetic potential of grain yields, infectious diseases play a significant role. Among the phytopathogenic organisms which cause cereal diseases, microscopic fungi represent the most numerous groups. Cereal infestation with phytopathogenic fungi is a reason of the decrease in grain yield and reduction of its quality, and in some cases its complete loss. It causes significant damage to agriculture. Loss of grain yields from fungal diseases varies in different years from 5 to 30%, and in the conditions of epiphytotic can reach up to 50% or more. Analysis of the epidemiology of cereal fungal infections in the agrocenoses of different climatic and geographical zones of Ukraine is important for planning preventive measures for the development and spread of these diseases. Correct analysis of the epidemic situation requires the availability of modern, standardized, highly informative, reproducible methods for specific detection of fungal pathogens in seeds and plant material. The dissertation is devoted to the research of the etiology of grain crops fungal infections on the territory of Ukraine, as well as to the improvement of existing methods of their molecular diagnostics and development of the ones new. The screening of the species composition and prevalence of fungi of the genus Fusarium in winter wheat grains by molecular biological methods using commercial test systems was performed. Based on the results of the analysis, 7 species of toxin-forming fusarium fungi were revealed and identified in the grain material. New data concerning the distribution of dominant species of fungi of the genus Fusarium in the grains of winter wheat in 78 districts, which are part of 21 regions of Ukraine were obtained. The species composition of the pathogenic complex of fusariosis was detected. It is shown that the pathogenic grain complex is dominated by 3 species - Fusarium graminearum Schwabe, Fusarium sporotrichioides Sherb. and Fusarium avenaceum (Fr.) Sacc. The total proportion of these species among all identified is 70.7%.