Моніторинг та діагностика вірусних хвороб соняшника (Helianthus annuus L.) в агроценозах України

Ukraine, as an agrarian state, is not immune to the challenges associated with the development and spread of viral plant diseases in agrocenoses. In addition to the direct ecological damage, there is a risk of introducing new viral pathogens and their establishment in our fields, the consequences of which are difficult to predict. The widespread, uncontrolled use of chemical plant protection agents and the disruption of crop rotation practices contribute to the spread of viral plant diseases and the emergence of new, resistant mixed infections with increased pathogenicity. Around 70 pathogens have been identified in sunflower crops, leading to annual yield losses of 20–45%, as well as a decline in seed quality and its suitability for sowing. The aim of this study was to analyze the current state of virus distribution affecting sunflower crops, with an identification of the viral species in certain regions of Ukraine, and to test commercial seeds of different sunflower varieties. This study employed a range of methods, including visual diagnostics, enzymelinked immunosorbent assay (ELISA) in various modifications, biological testing, and statistical data analysis. Through visual diagnostics, various symptoms of viral diseases were identified. The symptoms manifested in plants as necrosis, yellowgreen mosaic, swelling, leaf crinkling, enations, leaf blade curling, and plant dwarfing. As a result of testing 205 selected sunflower plant samples, 93 samples yielded positive results with test systems for cucumber mosaic virus (37 samples), tomato spotted wilt virus (35 samples), and tobacco mosaic virus (21 samples). It is noteworthy that plants infected with cucumber mosaic virus were detected in all research zones. Tomato spotted wilt virus was observed in the ForestSteppe zone (Kyiv and Vinnytsia regions), while tobacco mosaic virus was characteristic of the southern region of Ukraine (Odesa region). The infectious properties of the isolated viruses were studied using biological testing on indicator plants. The infections were carried out with viruscontaining plant samples from Kyiv, Odesa, Vinnytsia, and Cherkasy regions. The results on indicator plants infected with the isolated viral strains showed symptoms such as mosaic and leaf necrosis, characteristic of the studied viruses. Biological testing confirmed the infectious nature of the isolated strains of cucumber mosaic virus, tomato spotted wilt virus, and tobacco mosaic virus, as infected indicator plants exhibited typical viral symptoms, while control plants showed no symptoms. The seeds of 10 sunflower varieties were analyzed for viral pathogen contamination. Viral antigens were detected in the following seed varieties: Shannon, Amato, Sandera, Forward, Sunny Mood and NS SUMO 556. Overall, viral antigens were identified in the commercial sunflower seeds cucumber mosaic virus and tomato spotted wilt virus.