The content of reactive oxygen species, the activities of ascorbate-glutathione cycle enzymes, the content of low molecular weight antioxidants: ascorbate and glutathione, the activity of phenolic peroxidase, the content of water-soluble phenols and the expression level of the hypersensitive response marker gene (HSR) and PR protein genes (Chit, Glu and TLP) in potato seedlings grown on an ion-exchange substrate in the presence of jasmonic acid at a concentration of 10^-8 and 10^-6 M and infected with potato virus X were studied. Accumulation of reactive oxygen species, an increase in the content of reduced ascorbate and an intensive consumption of reduced glutathione upon action of jasmonic acid, as well as a sharp increase in the expression of HSR, Chit, Glu, and TLP genes in the leaves of potato seedlings grown on a substrate with the addition of 10^-6 M jasmonic acid before infection were shown. In control plants, the expression of the HSR and TLP genes increased only after infection with potato virus X.

Littlewale (Lithospermum officinale L.) is a valuable medicinal plant that has been used in folk medicine since ancient times as a diuretic, laxative, analgesic, anti-cold and anti-inflammatory agent. One of the most common classes of biologically active substances of plant origin are flavonoids. The leaves of the littlewale contain isoquercitrin, a flavonoid that has a regenerating effect.

This article presents the results of a study of the influence of extraction parameters (ethanol concentration, temperature, ratio of the mass of plant materials to the volume of extractant, duration, multiplicity) on the output of flavonoids from the leaves of the littlewale. Using the orthogonal central compositional planning, a dependence is obtained that describes the influence of temperature and the duration of the extraction process on the efficiency of extracting flavonoids from the leaves of the littlewale. It was found that the maximum yield of the target components, which is more than 2 %, is achieved with the following parameters of the extraction process: extractant - 50 % ethyl alcohol, the ratio of the mass of raw materials to the volume of extractant is 1:20, temperature - 65-70 °С, duration - 35-45 minutes. It is enough to conduct a single extraction of plant materials.

The results of the examination of bat collection of the Zoological Museum of Belarusian State University, Minsk, one of the largest natural history museums in Belarus are presented. The collection contains 226 specimens, collected in 1924-2006, mainly in Belarus (in all administrative regions). In the collection there are specimens of Vespertilionidae: Barbastella barbastellus, Eptesicus nilssonii, E. serotinus, Myotis daubentoni, Myotis ex gr. “mystacinus"-brandtii, Nyctalus lasiopterus, N. leisleri, N. noctula, Pipistrellus kuhlii, P. nathusii, P. pipistrellus s. l., Plecotus auritus, Vespertilio murinus; and as well one species of Pteropodidae: Rousettus aegyptiacus. Voucher data were digitized and systematized. The electronic catalog was compiled and conveyed to the Museum. The scientific and historical value of the collection is shown.

It is known that black grouse is a valuable resource species of the wild fauna of Belarus. The Belarusian population went through the stages of population decline and redistribution into new agrarian landscape territories - extensive anthropogenic involvement transformed significant parts of the species’ habitat in the course of large-scale land reclamation campaigns, which originated in 1950s. In order to rationally use the preserved black grouse subpopulations, an assessment of the level of their genetic diversity and degree of differentiation was made. For the latter purpose, microsatellite analysis was utilized. It was found that at the present stage the black grouse population has a sufficient level of adaptability (based on indicators of genetic diversity and effective population size) necessary to maintain viability in the foreseeable future.

It is known that tomato is one of the most susceptible vegetable crops affected by viral pathogens. Recently, Pepino mosaic virus, is widespread in greenhouse plantations in Europe the harmfulness of which leads to yield and marketability of products decrease.

The analysis of tomato hybrids grown in greenhouses of the republic has shown that in different years of research, Pepino mosaic virus has been present both in mono infection and in combination with the other viruses from the genus Cucumovirus, Tobamovirus, Nepovirus and Tobravirus.

Laboratory data indicate the susceptibility and ability to high accumulation of viral particles when test plants Datura stramonium L. and Nicotiana rustica L. have been infected with the pepino mosaic virus. It is determined that Aphis gossypii Glov., Frankliniella occidentalis Perg. and Trialeurodes vaporariorum Wetw. can participate in the vector transmission of the pathogen between host plants.

The features of the increment dynamics of Scots pine (Pinus sylvestris L.) in different regions of Belarus and the influence of climatic factors on it were analyzed. The dendrochronological zoning of Scots pine in Belarus (3 regions, 7 districts) has been developed for the first time on the basis of the identified responses. Master chronologies (98-170 years) were built for each from 7 dendrochronological districts. The temperatures of the winter months, March and April, as well as the amount of precipitations in June and July are the main climatic factors that determine the growth of pine in Belarus. It were established a significant decrease in the impact of precipitation during growing seasons on the tree increment from south to north on the one hand and an increase in the impact of spring and winter temperatures on the other.

The results of fauna study of National Park Narochansky (Minsk region) during the field seasons 2019-2020 are presented. We performed bat captures using mist nets and also surveyed settlements with an ultrasonic heterodyne detector. 177 specimens of 9 species were captured, specifically: Eptesicus nilssonii (Keyserling et Blasius, 1839), Myotis brandtii (Eversmann, 1845), M. dasycneme (Boie, 1825), M. daubentonii (Kuhl, 1817), Nyctalus noctula (Schreber, 1774), Plecotus auritus (Linnaeus, 1758), Pipistrellus nathusii (Keyserling et Blasius, 1839), P. pygmaeus (Leach, 1825), Vespertilio murinus (Linnaeus, 1758). 11 settlements of bats were discovered and mapped within the study area. According to the mist net captures, the dominant species is P. nathusii, with subdominant M. daubentoniid; andM. brandtii with P. auritus as the rarest species. Other species had represented ratios of 2.7 to 9.5 % in the nets captures. Species E. nilssonii andM. brandtii are only represented by male specimens. We also report the first registered discovery of Myotis brandtii on the territory of National Park Narochansky, which is also the most northern registration of that species in Belarus. In comparison to the previous studies, we have confirmed the presence of several species with previously questionable local status: P. auritus, M. brandtii, M. daubentonii and V. murinus.

The biological effectiveness of the active substances 2.4-D, clopyralide and glyphosate (Sigma, USA) in relation to ragweed under the controlled laboratory conditions was studied. The number of physiological parameters (plant height, leaf formation, stem diameter, chlorophyll content, dry weight accumulation) of the studied plants were also evaluated. It was found that treating ragweed plants having 3 pairs of leaves by herbicides 2.4-D, clopyralid and glyphosate showed maximum biological effectiveness and the level of inhibition of physiological processes at doses of 530, 461, and 406 g/ha respectively. The biological effectiveness of herbicides was 86 % for 2.4-D, clopyralid - 83, glyphosate - 80 %. It was revealed that in order to speed up and optimize the process of testing the effectiveness of herbicides against ragweed in the field, the express method for determining the chlorophyll content with the DUALEX portable flavonol-chlorophyllometer can be used. This indicator will determine the effectiveness of herbicides already on the 7th day after treatment, which will significantly accelerate the selection of substances and herbicide consumption rates.

In the research work performed, the influence of the growth regulators Ecosil Plus, Ecosil Mix, and the nanoplant Nanoplant, as well as composite compositions based on them on the growth and development of pine and spruce seedlings was studed The effect of drugs and protective-stimulating compositions on the degree of infection of planting material by phytopathogenic fungi, on changes in physiological and biochemical parameters of disease resistance and on biometric indicators of seedlings has been studied.

As a result of laboratory studies, a positive effect of growth regulating substances based on the Ecosil growth regulator on the initial development of pine and spruce seedlings after presowing treatment was revealed. On the development of the root system, Ecosil Mix provided greater efficiency, causing an increase in the length of the main root by 39 and 56 % for pine and spruce, respectively. And Ekosil Plus more strongly influenced the formation of the above ground part of seedlings, raising the height of plants by 14 % in pine and by 26 % in spruce.

Foliar treatments of pine and spruce seedlings grown under laboratory conditions with various forms of growth regulators based on the Ekosila growth regulator induced adaptive physiological and biochemical processes in plants. In needles of pine and spruce under their influence, the amount of pigments increased on average by 50-60 %. The level of lipid peroxidation of membranes and the yield of water-soluble substances decreased in plants by 30-50 %, which indicates the membranotropic effect of growth regulators.

Based on the laboratory selection, it was found that for foliar treatment of plants it is preferable to use Ecosil Mix (1.0 l/ha), Ecosil Plus (1.5 l/ha) and Nanoplant (0.1 l/ha) which during the two vegetation periods were investigated in the nurseries of Molodechno and Klichev forestry. Studies conducted in the conditions of open and closed ground showed that all the studied growth regulators and their mixtures have a positive effect on the growth of seedlings, as well as improve the physiological and biochemical indicators of disease resistance.

Histaminergic neurons in adult vertebrate brain are confined to the posterior hypothalamic area, where they are comprised of scattered groups of neurons referred to as the tuberomammillary nucleus. Histamine regulates hormonal functions, sleep, food intake, thermoregulation and locomotor activity. Histaminergic neurons in adult animals under normal conditions and in some pathological conditions are described. However, a study of these neurons development in the postnatal ontogenesis dynamics has not been conducted.

The morphofunctional state of histaminergic neurons of the hypothalamic E2 nucleus in the postnatal ontogenesis dynamics was assessed. The study was performed on the offspring of outbred white rats (45 animals). The decapitation of animals was carried out on the 5, 10, 20, 45 and 90th days after birth. We used histological, histochemical, morphometric and statistical research methods. The data obtained were processed by nonparametric statistics methods.

From the 5th to the 90th day of rat postnatal ontogenesis, there is a significant increase in the size of the histaminergic neurons pericarions of the hypothalamic E2 nucleus (especially from the 5th to the 10th day). It is accompanied by a decrease in the bodies location density of the studied cells and an increase in the distance between them (especially from the 5th to the 20th day), which indicates a neuropil intensive growth. Over the indicated period of postnatal development, a significant decrease in the hyperchromic neurons number is observed, which correspond to a decrease in the ribonucleoproteins amount in the cytoplasm of the described neurocytes.

Development of brain histaminergic neurons from the 5th to the 90th day of rat postnatal ontogenesis is characterized by an intensive growth of their pericaryons, a decrease in their location density and stabilization of the morphofunctional state of the studied neurocytes.

Dendrimers are hyperbranched polymers belonging to the class of nanomaterials. These nanostructures and their derivatives (dendrons and dendronized nanoparticles) are multi-target nanocarriers that can be modified to achieve various tasks. For example, it is possible to increase biocompatibility and stability, to control the release of active substances. Their widespread use in biology and medicine requires an understanding of the basic mechanisms of their interaction with proteins - one of the main biological systems. The interaction of dendrimers with proteins may vary depending on the size of the ones, surface charge, structure and stiffness of the branches. Here, both electrostatic interactions arising due to the presence of dendrimers and surface charge proteins, as well as hydrophobic ones, due to the corresponding cavities in the structure of dendrimers, can manifest themselves here. The formation of hydrogen bonds is possible. All these interactions in one way or another can affect the structure and functions of proteins.

Present article discusses the mechanisms of interactions between dendrimers, dendronized nanoparticles and protein macromolecules. The effect of nanoparticles on the secondary structure, conformation, dynamics and functional activity of proteins is reviewed. The different models for dendrimer-protein interactions are described.