The effect of ethanol (0.1, 0.3, and 1.6 %) on the content of photosynthetic pigments, astaxanthin, and reactive oxygen species (ROS) in Haematococcus pluvialis (H. pluvialis, strain IBCE H-17), as well as on algae productivity, was studied in terms of dry biomass. Ethanol was found to stimulate in the studied concentrations the accumulation of dry biomass for 3, 7, and 12 days of cultivation on average 2 times. At all used ethanol concentrations, the number of cells increased. So, when using 0.3 % ethanol, the number of cells increased by 2.1; 2.5 and 3.3 times compared with the control culture on days 3, 7 and 15 of haematococcus cell growth. At the same time, a tendency toward a decrease in their size was noted. Ethanol also stimulated the accumulation of photosynthetic pigments. So, after 3 days of incubation in a solution containing 0.1 and 0.3 % ethanol, the content of chlorophyll (Chl) a was 142 and 130 % of that in the control, respectively, Chl b – 126 and 115 %, lutein – 151 and 132 %. The maximum effect was noted for β-carotene – 177 and 157 % compared with the control. The stress conditions created by ethanol led to the generation of ROS, in particular, after 7 days of incubation using 0.1; 0.3 and 1.6 % ethanol, the amount of ROS was 114, 141 and 179 % of that in the control, and after 12 days of incubation, 130, 165 and 183 %, respectively. A significant positive effect of ethanol on the content of astaxanthin was noted. So, after 7 days of incubation, the content of astaxanthin in options of 0.1; 0.3 and 1.6 % increased by 3.6; 4.9 and 4.6 times, respectively, and after 12 days – 8.6; 6.6 and 7.7 times compared with the control. The results indicate the enormous potential of using ethanol as an effective inducer of astaxanthin accumulation in haematococcus cells, as well as an active stimulator of algal productivity.

The analysis of the biotic component in determining of the quality of surface water is becoming increasingly important. The aim of the work was to assess the ecological quality of the river ecosystems from the influence of wastewater discharges of the Grodno, Stolbtsy and Vileyka cities on the Neman and Viliya rivers based on the macrozoobenthos community.

The rare and protected species of hydrobionts from number of European countries live in the studied rivers. Among them are mollusks, coleoptera, caddis flies, and crustaceans. The stoneflies – highest priority indicator group of hydrobionts is missing in the Neman river. Mayflies and caddis flies are also poorly represented (2nd and 3rd indicator groups). The all three main indicator groups of aquatic organisms are presented in the Viliya river. The biotic indices are determined and the class of water purity of the studied rivers was calculated. In accordance with the EU Water Framework Directive, the cleanliness class has good and high value. It is concluded that the negative impact of wastewater from the cities of Grodno, Stolbtsy and Vileyka is of very local importance and weakly affects the biota and ecological quality of the water of the Neman and Viliya rivers.

The unique results of the 25-year monitoring of forest vegetation of the buffer zone at the Novopolotsk Refinery Complex (NIRC) were summarized. The analysis of quantitative and qualitative changes in the buffer zone, which occurred during the period 1990–2015 years of operation of NRC’s enterprises, is given. Detailed analysis of vegetation organization has shown that the most transformed forest areas are directly adjacent to the enterprises from the leeward side. During the 25-year period of research, the area of primary forest fragments in the 500-meter zone of NRC impact has decreased by 2.6 times. Derivatives of small-leaved communities formed at the place of dead coniferous stands immediately after the commissioning of the plants are presented here. The technogenic press reduction in the 1990s resulted in the active demutation transformations of vegetation. Recently, there has also been a dominance of restoration processes, but the change of the main pine and spruce stands to derivatives continues, which is reflected in the prolonged decomposition of fragments of previously disturbed stands. The direction and rates of change of some plant groups by others depend on the initial state of plants, species and age structure of communities, conditions of their growth and environmental factors. In general, it is noted that forest ecosystems of the region have retained the ability to regenerate the composition and structure.

An entomopathogenic fungi belonging to the genus Cordyceps was isolated from the affected larvae of the bloodsucking blackflies Wilhelmia equina (Linnaeus, 1758). Larval stage of Simulium were collected on the territory of the Lepel district of the Vitebsk region in the river Essa in July 2018. Isolate was identified using cultural-morphological and molecular-genetic methods.

In vitro experiments comparative evaluation of biological activity of isolated strain Cordyceps sp. and Beauveria bassiana 10-06 was carried out for 3rd instar larvae of W. equina. Two different concentrations 1∙10⁶ and 1∙10⁷ conidia/ml were made and tested in 3 replications. On the 3rd day of incubation both fungi caused a significant mortality of test-objects (p = 0.03) compared to control. The biological efficiency of the concentration of 10⁷ соnidia/ml of the strain Beauveria bassiana 10-06 on the 3rd day was 94.4 %, on the 4th – 98.3 %, of the strain Cordyceps sp. – 76.0 and 88.9 % respectively.

The results of studies on the presence in the seeds of legumes and cereals of protein inhibitors that are active against animal proteinases (trypsin) and exogenous peptidases of phytopathogenic microorganisms are presented. It has been shown that secreted proteolytic enzymes of the studied phytopathogens are mainly represented by cysteine proteinases, to a lesser extent, serine and aspartane proteinases are present. It has been established that a close positive correlation between plant resistance to pathogens is observed not with well-known and widespread trypsin inhibitors, but with the activity of inhibitors directed against exogenous peptidases secreted by fungal pathogens of the genus Fusarium, Colletotrichum and Helminthosporium. The results obtained in the course of the work can be used in breeding and genetic studies on the creation of varieties and types of crops with increased resistance to pathogenic microflora and insect pests, as well as to create protective preparations.

The article describes results of a comparative study conducted in seasons of contrasting hydrothermic regimes of averaged variation coefficients of 14 indexes of biochemical composition of fruits of 4 species of introduced plants from families Ericaceae and Actinidiaceae – O. macrocarpus, V. corymbosum, A. arguta and A. kolomikta. It has been shown that the highest integral resistance of biochemical composition of fruits to the complex impact of meteorological factors among O. macrocarpus varieties is characteristic of the released Stevens variety, the lowest one – of Holistar Red, among V. corymbosum varieties – of Bluejay and Sunrise respectively. In the taxonomic row of A. arguta the highest resistance to abiotic factors is found in the natural form, the lowest one – in Sentjabrskaja variety, in the taxonomic row of A. kolomikta – in Aromatnaja and Sentjabrskaja varieties respectively. The greatest variability in all or most introduced varieties is characteristic of parameters of accumulation in fruits of dry substances, hydroxycinnamic acids, soluble sugars and the total amount of bioflavonoids, as well as the content of pectin substances for both species of Actinidiaceae family. At the same time, O. macrocarpus is characterized by high stability of the content of titrated acids and anthocyanin pigments in fruits, V. corymbosum – of catechins, flavonols and tannins, A. kolomikta – of titrated acids, leucoanthocyanins and catechins. Accordingly, the most distinct dependence on the seasonal hydrothermal regime has been found in O. macrocarpus for its sugar-acid index and the content of catechins in fruits, in V. corymbosum – for that of pectin substances and true anthocyanins, in A. arguta – for catechins content, for A. kolomikta – for that of ascorbic acid and flavonols.

There are research results of the localization of coumarins in roots. Coumarins accumulated in the form of a white secret (latex) in the secretory structures of roots. Chromatographic separation of latex showed four furocoumarins in the roots of Heracleum. These are angelicin, bergapten, xanthotoxin and psoralen.

It has been established that the racoon dog is a definitive host of epidemic and epizootic significance types of helminths, as a result of which on the territory of the Poles State Radiation and Environmental Reserve formed natural pockets of alariosis, thrichinellosis, sparganosis, opistorhosis, paragonimosis, etc.

In the Jumgal River basin have been identified 223 species of phytopathogenic fungi and fungi-like organisms on 76 species of vascular plants from 125 genera. The distribution of phytopathogens in 8 economically useful plant groups was shown: forage, medicinal and alkaloid, honey, feeding, essential oil, dyeing, ornamental and weed plants.

The proliferation activity of blue honeysuckle microplants of cultivars ‘Krupnoplodnaya’, ‘Goluboye vereteno’, ‘Pavlovskaya’, ‘Volkhova’ at micropropagation stage is determined by hormonal composition of nutrient medium and genotype. An increase in concentration of 6-BA in MS medium from 0.2 to 1.5–2.0 mg/l leads to an increase in micropropagation rate from 1.91 to 3.26–3.57. The maximum micropropagation rate for cultivars ‘Krupnoplodnaya’ (3.43–3.47) and ‘Goluboye vereteno’ (4.11–4.23) was given at MS medium with addition of 1.5 and 2.0 mg/l 6-BA, for cultivars ‘Pavlovskaya’ and ‘Volkhova’ (2.80 and 3.90 respectively) – at medium with addition of 1.5 mg/l 6-BA. It is possible to increase micropropagation rate due to the joint use of two growth regulators: 6-BA (1.5–2 mg/l) and GA3 (1.0 mg/l). The use of gibberellic acid leads to formation of axillary branch, intensification of growth by increasing the length of internodes of shoots, which makes it possible to further divide long microshoots into microcuttings with two to three nodes.

It was found that use of TDZ actively stimulates proliferation of blue honeysuckle shoots and allows to obtain a high micropropagation rate (up to 12) at lower concentrations (0.3–0.6 mg/l) than use of 6-BA in high concentration – 1.5 and 2.0 mg/l (micropropagation rate was 2.80–4.23 depending on cultivar). However, TDZ inhibits growth of microshoots in length, forming a conglomerate, which is an accumulation of small shoots that are not suitable for rhyzogenesis stage, and therefore their subsequent elongation on a hormone-free medium is necessary. The use of TDZ in two consecutive subcultures for cultivating of blue honeysuckle is not desirable, as it leads even more to formation of small shoots.

Different pines species are heavily infected with fungal pathogens all over the world, some of them are alien species for European region. The potential invasion of alien species into forests, forest nurseries, urban greeneries causes great concern among Belarusian phytopathologists. In this regard, in recent years local scientists have been monitoring the phytosanitary state of natural and managed plantations to identify alien species. The aim of this investigation was to monitor the phytosanitary state of conifers in botanical and dendrological gardens, urban plantations and tree nurseries in the Republic of Belarus, and assessment of the incidence of alien pathogens of pines. There were used light microscopy and molecular genetic techniques. As a result of our research the brown spot needle blight fungus, Mycosphaerella dearnessii was for the first time noted in the region of the Republic of Belarus in a consignment of imported plants of pines Pinus mugo, Pinus nigra, Pinus ponderosa. The disease was revealed both on young and adult plants in botanical gardens and nurseries. In the forests, urban greeneries Mycosphaerella dearnessii is currently not identified. The fungus affects not only the old, but also young needles, strongly inhibiting the growth of trees. Based on the investigation results we suppose that this disease can be dangerous for pinetums in our country.

The recent data on epigenetic control of differentiation in mesenchymal stem cells to be the background of embryogenesis and regeneration process in organism are considered. Epigenetic control is bases on three intramolecular mechanisms – DNA methylation, structural modification of histone proteins and microRNA active on posttranscription and posttranslation levels. As an example, the issues of stem cell differentiation in the liver are considered.