Dynamics of pine stands dieback in 2016‒2021 in the forest fund of Belarus is presented. The area of clear sanitary cuttings was 112.3 thousand hectares.
The results of field tests on attractiveness assessment of Belarusian synthetic pheromones “IPSVABOL V”, “IPSVABOL SH”, “MONVABOL” using barrier traps for monitoring the abundance of sharp-dentated (Ips acuminatus G yll.) a nd s ixtoothed (Ips sexdentatus Boern.) bark beetles and longhorn beetles (Monochamus spp.) in pine stands are presented. During insect abundance monitoring in pine stands, it was found that the synthetic pheromone “IPSVABOL V”, “IPSVABOL SH” and “MONVABOL” are highly attractive to beetles of the sharp-dentated, six-toothed bark and longhorn beetles of the genus Monochamus when monitoring their abundance in pine stands. It was revealed that the first generation flying of the sharpdentated and six-toothed bark beetles are the most widespread and higher by 1.8‒4.5 and 3.8‒5.1 times of the second generation flying of these stem pests, respectively.
For the first time, scales for assessing the abundance and methods for pheromone monitoring of the sharp-dentated and six-toothed bark beetles, and longhorn beetles (Monochamus spp.) have been developed. The use of the developed scales in forest protection practice makes it possible to quickly control the abundance of these stem pests and their distribution in pine stands for appointment of forest protection measures.

The article contains the results of study of the influence of added to culture medium silver-containing chitosan- based nanocomposites (Chitosan-Ag) at a dilution of 1:500 and 1:1000 (the mass ratio of the components is 50:1 for Chit- Ag 50:1 and 100:1 for Chit-Ag 100:1) on the development of potato microshoots and microclones with a formed root system. Potato microshoots cultivated for 4 weeks on nutrient medium modified with nanocomposites were characterized by slow development and the absence of rhizogenesis, which indicates the toxic effect of the studied nanocomposite concentrations. When replacing the standard nutrient medium with nanocomposites modified for a potato microclone with developed roots, the Chit-Ag 50:1 reduced the rate of growth and development of microclones compared to control and pure chitosan. The Chit- Ag 100:1 nanocomposite had no influence on the microclone growth compared to the control, but reduced the root biomass compared to chitosan. The preservation of photosynthetic pigments and proline concentrations with decreasing the hydrogen peroxide level indicates the absence of the toxic effect of silver-containing chitosan-based nanocomposites on the formed potato microclones. The chitosan concentration increase in the nanocomposite composition helps us to reduce the toxic effect due to the formation of a dense stabilizing shell that delays the silver ion generation.

The objects of research were the first leaves of green seedlings of spring barley (Hordeum vulgare L.) of the varieties of Belarusian breeding − filmy (Magutny, Raider) and naked (Adamant). Seedlings of different age (3, 5, and 10 days old) were infected with spores of the fungus Bipolaris sorokiniana (Sacc.) Shoem. − a causative agent of helminthosporiasis, and were analyzed 2 days after infection. Varietal and ontogenetic differences between barley cultivars in morphological parameters of the first leaves, the content of photosynthetic pigments (chlorophylls (Chl) and carotenoids), and the ratio of spectral forms of Chl at the seedling stage were found. Different amplitudes of changes in the photosynthetic pigment content between the barley varieties with helminthosporiasis at different stages of development of the first leaf were established.

Prevention by immunizing cattle against tuberculosis with traditional vaccines and regular testing has long been the main method of controlling this infection. However, the non-specificity of the traditional method shows the need for alternative approaches in the creation of anti-infective vaccines. The development of recombinant vector vaccines based on influenza vectors shows great potential and advantages in providing a specific immune response.
The purpose of the study is to evaluate the growth properties of the recombinant influenza virus strains expressing protective proteins of mycobacteria for further use in creating a vector vaccine against bovine tuberculosis.
This article presents the results of work on the cultivation and reproduction of recombinant influenza virus strains. Using reverse genetics methods, recombinant strains of the influenza virus carrying the mycobacterial Mycobacterium bovis ESAT-6 and TB10.4 proteins in the NS gene sequence were constructed. Based on the results of the work carried out, the optimal conditions for cultivating recombinant influenza virus strains were determined. Both variants of the recombinant strain showed reproductive activity in the developing chick embryo system, under optimal cultivation conditions.
The evaluation of the genetic stability of the insertion of mycobacterial proteins into the NS gene of the influenza virus was confirmed using the RT-PCR method. As a result, it was found that the NS gene segment contains an insertion of mycobacterial proteins TB10.4 and ESAT-6, which is retained throughout the studied 5 passages.

The study of invasive alien species is carried out on a large scale because the economic and ecological damage caused by biological invasions is enormous. However, no unified approach to describing invasive populations has been developed so far. In the framework of alien plant inventory in Russia, the authors have developed the “Invasive Species Assessment Protocol”, which is a tool for assessing, categorizing and including in the “black”-lists any invasive alien plant species according to its impact on native species and natural biodiversity over a large geographic area. “The Protocol” contains five basic elements of the inventory: 1) taxonomic affiliation, life form, and natural range of species; 2) ecological impact; 3) current distribution and population size; 4) trends in abundance of populations or its size; and 5) ability to control alien species dissemination. “Protocol” is presented as the special blank for description of local invasive population. The description is very brief but, if necessary, additional information about the process of invasion of each alien species can be added to it. Specific additions to the protocol for some national economic objects: railroads, introduction institutions, Specially Protected Natural Areas (SPNA) are offered. Examples of using the Protocol during the inventory of invasive species on the Trans-Siberian Railway, in the NV Tsitsin Main Botanical Garden, and in the some Protected Natural Areas are given.

The increase in prevalence of antimicrobial-resistant bacteria (ARB) is currently a serious threat, thus there is a need for new classes antimicrobial compounds to combat infections caused by these ARB. The growth inhibition ability of derivatives of the components of nucleic acids has been well-characterized but not for its antimicrobial characteristics. It was found that modified nucleosides arabinofuranosylcytosine (cytarabine, ara-C), [1-(2′,3′,5′-tri-O-acetyl-β-D-ribofuranosyl)- 4-(1,2,4-triazol-1-yl)]uracil (TTU), and nucleotides cytarabine-5′-monophosphate (ara-CMP), and O2,2′-cyclocytidine-5′- monophosphate (cyclocytidine monophosphate, cyclo-CMP) were able to inhibit Escherichia coli, Sarcina lutea, Bacillus cereus, and Proteus mirabilis strains in a time and dose dependent manner via killing kinetics assay. It was demonstrated that studied modified pyrimidine nucleosides derivatives enhanced the production of intracellular reactive oxygen species (ROS) over time (validated via DCFA-DA probe assay). This study has revealed the mechanism of action of cytarabine, cyclocytidine monophosphate, and TTU as an antimicrobial agent for the first time, and has shown that these pyrimidine derivatives enhanced might be able to combat infections caused by E. coli, S. lutea, B. cereus, and P. mirabilis in the future.

The analysis of the recent phylogeographic studies of Microtus arvalis is carried out to establish the post-glacial history of colonization of the common vole in the Central region of Europe. The authors have presented the original data on the genetic variability of the _mtCytb gene of the common vole (Microtus arvalis s. l.) from 18 localities studied on the territory of Belarus. The genetic characteristics of 53 individuals of the common vole belonging to one eastern line of mitochondrial DNA were studied. It is shown that the population of the species in Belarus is characterized by a high level of genetic diversity comparable to that of other haplogroups of the eastern mtDNA line. The level of variability of mitochondrial fragments of the mtCytb gene of the common vole (Microtus arvalis) from Belarus turned outtobeq uite high (Hd ± SDHd = 0.97 ± 0.02), which is manifested in a large number of the identified _mtDNA haplotypes (n = 41). The distribution of the identified haplotypes of Microtus arvalis across various landscape-geographical areas correlates well with the location of the most remote haplotypes on the parsimony network. The assumption is given about the re-settlement (about 9000 thousand years ago) and further settlement of Microtus arvalis on the modern territory of Belarus in two directions: from southeast to west and to northwest, as well as from north to southeast.

Three fundamental processes running in plant organisms under influence of environment (light, gravity) and key importance were considered. In the light case these are phytоchrome regulation and phototropism considering process is gravitropism. Phytochrome is responsible for regulatory reaction at the inhibition of which the plants cannot be normally developed. The plants do not need phototropism and gravitropism. They were elaborated by evolution as protective reactions to optimize the plant vitality. All these processes are realized according to one and the same logical scheme: stimulus reception, signaling processes in plant cell (transduction) and proper biological effect. According to this scheme the three reactions were considered. As the result the data adout the reception stages are principally different because receptor nature. Signaling processes proceed with participation of many low molecular and high molecular mediators to participate and biophysical, biochemical and genetic reactions. One fact attracts attention that the same mediators are involved to signaling ending by principally different final biological effect.This allows to suggest the existance in plant cell no separate chains for each stimulus but regulatory network formed by lateral and horizontal transduction chains.