Tsvigun V. The variety of plant viruses from the Cucurbitaceae family in Ukraine

Thesis is focused on studying diversity and molecular characterization of the most harmful viruses endangering Cucurbitaceae plants in Ukraine. The research showed that 141 out of 311 plant samples from the Cucurbitaceae family were positive for CMV, ZYMV and WMV-2. A phylogenetic analysis was conducted for the most spread viruses infecting cucurbit plants in Ukraine. For the first time in Ukraine, the phylogenetic analysis was carried out for the amplified cDNAs of coat protein gene of Ukrainian WMV-2 isolates. It was confirmed that Ukrainian WMV-2 isolates were related to European and Middle East strains and isolates. It was shown that Ukrainian isolates of ZYMV belonged to the first subgroup of Group A and were related to the isolates from Austria, Slovenia, Serbia, Hungary, Slovakia and Venezuela. Also it was determined that Ukrainian CMV isolates were attributed exclusively to subgroups IA and IB of cluster I. The polyclonal antiserums to WMV-2 and CMV were generated giving the opportunity to create in-house diagnostic test systems to these viruses. Additionally, it was found that 'Dekoneks-50 FF' substance had antiviral effect against CMV. All obtained sequences of Ukrainian isolates of CMV and WMV-2 were made public in the international genetic database (GenBank) allowing their use in laboratories around the world.