Shchetynina G. Molecular-biological characteristics of Hosta Virus X, which is new for Ukraine

Samples of hosta plants with visible symptoms or without visible symptoms were selected for primary detection. As a result of ELISA diagnostics using Ab for HVX from hosta plants of the Sum and Substance variety, a serologically related virus was detected. To determine the causative agent, this sample was used for the EM analysis and RT-PCR. As a result of electron microscopic examination, viral particles with typical morphology for a representative of the genus Potexvirus were found. As a result of a reverse transcription PCR with a specific primer pair to the coat protein of HVX, an amplicon of the 706 bp was obtained. Thus, for the first time the virus was detected in Ukraine in 2012. A specific antiserum was obtained for the Ukrainian HVX isolate. Later, a high quality testing system was created to monitor the planting material. Analysis of collections of the Kiev botanical gardens confirmed the effectiveness of the obtained diagnostics antibodies. In particular, high dynamics of the HVX transmission was shown among collections of hosta plants of the M.M. Gryshko National Botanical Garden. It was also observed that the pathogen was absent in the hosta plant collection in the A.V. Fomin Botanical Garden named after Taras Shevchenko. The virus transmission capacity by seeds of infected plants was ascertained. Total RNA was extracted from plant material and a 706-bp fragment corresponding to nt position 5722–6448 in HVX-Kr was amplified in RT-PCR from the samples of 'Sum and Substance', 'Ultraviolet Light', 'Gold Standard', 'Halcyon', 'Great Expectations' and 'Сrispula'.