Wheat dwarf virus and its impact on the 2020 harvest in some regions of Ukraine

Goal. Identify the virus that causes symptoms of dwarfism and non-earing of winter wheat (reduced or no ear formation), and investigate its effect on plant yields. Methods. Visual diagnostics, enzyme-linked immunosorbent assay in double sandwich modification (DAS-ELISA), polymerase chain reaction, biometric, determination of yield and its structure, statistical data processing. Results. A study of winter wheat varieties from Vinnytsia, Khmelnytsky, Kyiv, Chernihiv and Cherkasy regions with symptoms of dwarfism, yellowing of leaves and non-earing. ELISA and PCR have shown that the disease is caused by Wheat dwarf virus. The absence of Wheat streak mosaic virus, Barley yellow dwarf virus, Brome mosaic virus and Wheat spindle mosaic virus (Wheat streak mosaic virus) was shown in the studied samples. It was found that the dwarf wheat virus significantly reduces the number of grains in the ear (3.3 times), the weight of grains from the ear (3.4 times) and the weight of 1000 grains (1.9—3.3 times) depending on the degree of damage plants (from moderate to severely affected). Conclusions. The circulation of dwarf wheat virus in agrocenoses of five regions of Ukraine and a significant negative impact of the disease on the yield of winter wheat plants have been established. The obtained results indicate the need for constant monitoring and testing of plants for the presence of wheat dwarf virus in Ukraine.