[Properties of potato virus M and potato virus Y isolates in Ukraine].

Monitoring of viruses of tomato plants (Lycopersicon esculentum Mill.) was carried out. Twenty-seven varieties of tomatoes from different regions of Ukraine were tested for the virus presence. New symptoms, which had not been described before, were revealed. It was found out that the diseases were caused by Potato virus M and Potato virus Y. This is the first report about the infection of tomato plants with such viruses in Ukraine. Some biological, physical and chemical properties of the pathogens are studied. Differences between PVM, PVY and the known isolates were found in morphology and molecular weight of structural protein.

[Role of siRNAS and miRNAS in the processes of RNA-mediated gene silencing during viral infections].

Phenomenon of RNA-induced gene silencing is a highly conservative mechanism among eukaryotic organisms. Several classes of small RNAs (siRNAs and miRNAs) 21-25 nt in length, which play a significant role in the processes of development of an organism, occurred important components of antiviral defence in animals and plants. This review shortly describes the main stages of gene silencing mechanism, features of antiviral RNA silencing in plants, invertebrates, mammals, ways of suppression of RNA-interference by viruses, as well as possible approaches of utilization of abovementioned phenomenon for struggling against viral infections.

[Monitoring of cereal viruses in agrocenoses of Ukraine].

Different Ukrainian agrocenoses have been investigated for the presence of the most harmful cereals viruses. The highest percent of virus infected plants was established in the Kyiv, Chernigiv, Vynytsya and Kherson Regions. Bromegrass mosaic bromovirus (BMV), barley yellow dwarf luteovirus (BYDV-Pav), wheat streak mosaic rymovirus (WSMV) are the most distributed viruses. The soil transmitted viruses such as wheat spindle streak mosaic bymovirus (WSSMV), barley mild mosaic bymovirus (BaMMV), soil-borne cereal mosaic furovirus (SBCMV) were detected in Ukraine for the first time. These viruses are transmitted by means of Polymyxa graminis. SBCMV was most often detected one.

[Characteristics of green mottle mosaic virus isolates in cucumbers from different regions of Ukraine].

Isolates of Cucumber green mottle mosaic virus (CGMMV) obtained from three greenhouses of Ukraine were identified. The rabbit antisera have been obtained for these isolates. These antisera can be used for diagnostics of CGMMV in plant material by indirect ELISA. An analysis of cDNA sequences of capsid protein of these viruses confirmed that they might be grouped into the novel strain of CGMMV.

[The course of virus infection of Lycopersicon esculentum plants at high concentrations of heavy metals]. / Perebih virusnoï infektsiï u roslyn Lycopersicon esculentum pri vysoykh kontsentratsiakh vazhkykh metaliv.

Effect of certain compositions of heavy metals on the course of the system infection of TMV in plants of tomatoes Lycopersicon esculentum L. under field conditions was investigated. It is shown that the simultaneous influence of the virus infection and heavy metals in concentration of 10 MPC (maximum permissible concentration) resulted in the decrease of the content of total chlorophyll in the investigated plants by degradation of chlorophyll A; that was more considerable decrease as compared with separate influence of each of the factors. Treatment of plants by toxical concentrations of lead and zinc led to inconsiderable delay in development of the system TMV infection together with the increase of the virus content in plants 2 and more times, that evidences for the probable synergism in the action of the given heavy metals and virus infection. On the contrary, copper, though it decreased the content of total chlorophyll, manifested the protective properties and restricted essentially the virus accumulation in a plant as a whole.

[Viruses of orchids of the natural flora in Ukraine]. / Virusy zozulyntsevykh pryrodnoï flory Ukraïny.

Orchids from biogeocenosis of natural landscapes of Ukraine (the Crimea, Carpathians) were analyzed for presence of viral pathogens. It is demonstrated that tobacco rattle virus (TRV), tomato aspermy virus (TAV), cymbidium mosaic virus (CymMV) and arabis mosaic virus (ArMV) are the most spreaded pathogens of orchid plants. There are orchid species distinguished in natural flora of Ukraine with characteristic high frequency of viral infection.

[Use of atomic force microscopy to study the morphology and structure of viruses]. / Ispol'zovanie metoda atomno-silovoi mikroskopii dlia issledovania morfologii i strukturnoi organizatsii virusov.

The paper describes AFM methodic approaches in the investigation of viruses (TMV, phage T4). A possibility is shown to use this method to obtain high-quality three-dimensional image of objects without additional treatment with salts of heavy metals. The phage T4 was also a model to study the object density, using the phase shift of the AFM. Such researches can determine the internal structure of a virion and folding of nucleic acid inside a virion.

[The microflora in suppurative-catarrhal endometritis in cattle]. / Mikroflora pri gnoino-kataral'nykh éndometritakh krupnogo rogatogo skota.

Microflora isolated from cattle with acute postnatal pus-catarrhal endometritis has been studied. It is shown that the given pathology is caused by associations of different bacterial species. 284 strains isolated from the uterus content of 63 sick animals have been identified, their properties being studied. Pathogenic gram-negative bacilli and gram-positive pus-producing cocci are responsible for the studied pathology. Considerable inoculation capacity has been established for conditionally pathogenic microorganisms of different species and genera whose role in pathogenesis is to be found out.