MIXED VIRAL INFECTIONS IN VEGETABLES IN UKRAINE

Aim. Screening of vegetable crops for mixed viral infections caused by 8 viruses, and evaluation of relative share for different combinations of pathogens using serological methods for plant virus diagnostics. Methods. Double-antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) was performed for detection of viral antigens. Results. For this study, the samples from plants with virus-like symptoms were collected from the agroecosystems in 4 regions of Ukraine during three vegetative seasons in 2019-2021. Plant samples were tested for presence of the following viruses: cucumber mosaic virus (CMV), watermelon mosaiс virus 2 (WMV2), zucchini yellow mosaic virus (ZYMV), tomato mosaic virus (ToMV), tobacco rattle virus (TRV), potato virus Y (PVY), potato virus X (PVX), and tomato spotted wilt virus (TSWV). Among the screened plants with virus-like symptoms, three viruses were the most common: CMV, WMV2 and ZYMV, with the incidence rate of 32%, 33% and 29%, respectively. Apart from monoinfected plants, several patterns of mixed infections were shown typically induced by two and less commonly by three viruses (CMV+WMV2+ZYMV). From these patterns of mixed infections, five groups of pathogens were registered. Conclusions. In this work, we have analyzed cucurbit and solanaceous vegetable crops with virus-like symptoms for viral infections caused by 8 pathogens, and established virus combinations inducing mixed infections in the field. Five groups of pathogens were demonstrated as such combinations: CMV+ToMV, CMV+PVY, CMV+WMV2, CMV+ZYMV, and WMV2+ZYMV, with CMV+ToMV being the most common for tested plants. Also, there was one group of pathogens formed by three viruses CMV+WMV2+ZYMV. CMV has been shown present in every group of mixed viral infections in plants from both families, Cucurbitaceae and Solanaceae. The incidence rate for these combinations differed from 4 to 8%. The presented results are important in the context of ecology and epidemiology of viral diseases of vegetables.