The article presents an overview of the data on the distribution of the slowworm in Belarus and the results of molecular genetic species identification according to the mtDNA COI region of 19 representatives of the genus Anguis collected in 13 administrative districts of 5 regions of Belarus (except the Mogilev region) in the period 2018‒2023. It has been established that only one species of legless lizards lives in the territory of Belarus – the Eastern Slowworm (Anguis colchica Nordmann, 1840). It was revealed that the Belarusian population of the species is characterized by low values of nucleotide (π = 0.00090) and haplotypic (Hd ± SD = 0.351 ± 0.111) diversity and is represented by two previously unknown haplotypes that are separated from haplotypes of other species by a genetic distance from 0.05740‒0.05995 (A. graeca) to 0.09439‒0.09694 (other species genus Anguis).

Methods for isolating metagenomic DNA from the rumen fluid of dairy cows have been selected and have made it possible to obtain high-purity nucleic acid preparations without PCR inhibitors. The probiotic potential of feed additives “Sporobact-K” and “Rumibact” based on spore-forming bacteria of the genus Bacillus and the propionic acid bacteria of the genus Propionibacterium were assessed. The feasibility of their use to increase resistance to opportunistic microbiota, improve ruminal digestion and control acidosis in cows was shown. The dominant taxa of the rumen microbiome of dairy cows were determined, and the primers and temperature-time parameters were selected for their detection by PCR. The feasibility of using feed additives “Sporobact-K”, based on bacteria of the genus Bacillus and “Rumibact”, based on propionic acid bacteria to control opportunistic microbiota, improve scar digestion and reduce the risk of acidosis in lactating cows is shown.

The elements of reproductive performance of Siberian shrimp Exopalaemon modestus (Heller) from Kapchagai reservoir (Republic of Kazakhstan) were studied. The value of reproductive performance was estimated in comparison with other shrimp species from the family Palaemonidae. Palaemonidae that in the middle of the growing season (July) was 0.24. The equations for the relationship between the oviposition weight and the weight of sexually mature females were calculated. The value of absolute fecundity averaged 68 ± 19 eggs (s. d.) to a female length of 35.8 ± 3.29 mm (s. d.). This relationship is described by the regression equation (determination coefficient R² = 0.583). Reproductive performance should be evaluated and analysed taking into account the age structure and time of the growing season.

CRISPR/Cas9 system is one of the effective tools for editing plant genomes. Using the CRISPR/Cas9 system, we have obtained different-type Nicotiana tabacum transformants carrying in their genome the mutational events of insertiondeletion type in the PDS gene, encoding15-cis-phytoene desaturase enzyme. The endogenous tobacco NtPDS gene was chosen as a target, since introducing mutations into its nucleotide sequence leads to appearing easily visualized characters. The tetraallelic knockout of the NtPDS gene led to complete albinism in plants. Albino transformants were characterized by a slower growth, dwarfism, and were not viable when cultivated in vitro. Mutants with variegated leaves in the in vitro culture formed roots and did not differ from the control in leaf size. A nucleotide sequence of the protospacer of the target NtPDSt gene was analyzed on a random sample, including 21 transgenic plants of the T0 generation with different phenotypes – from completely albino to wild type. Sequencing results showed that all transformants with visible phenotypic manifestations carried mutant sequences in the NtPDS gene with a frequency of 51.0–80.0 %, while the efficiency of site-directed mutagenesis was 33.33 %. In transformants of a wild-type phenotype, no mutated sequences were detected in the target gene.

The results of a comparative study are presented on the influence of the mineral Basacot Plus 6 (N15P8K12 kg/ha a. i.) and domestic biological fertilizers ‒ nitrogen-fixing and phosphate-mobilizing microbial MaKloR in 5 and 10 % concentrations, as well as organo-mineral Ecohum complex on the microbiological properties of the substrate under plantings of virginal and generative plants of early-ripening Ben Lear and late-ripening Stevens varieties of large-fruited cranberries in the experimental culture in the recultivated areas of top-type peat excavation in identical experiments in the Smolevichi district of the Minsk region, geographically distant 250 km from each other and in the more northern Dokshitsy district of the Vitebsk region.

It has been established that fertilizers have a predominantly inhibitory effect on the totality of the main characteristics of the microbiota under plantings of an early-ripening variety and, on the contrary, a stimulating effect under those of a lateripening variety. Under plantings of an early ripening variety in the Smolevichi district, regardless of the age of plants, the most significant deterioration in the state of microbial cenoses was found when applying mineral fertilizer and treating with the Ecohum complex, and in the Dokshitsy district ‒ when using MaKloR, especially in a 5 % concentration.

Under plantings of a late-ripening cranberry variety in the both areas under study, the tested fertilizers, on the contrary, contributed to the predominant activation of microbiological processes in the rhizogenesis zone. At the same time, in the Smolevichi district, regardless of the age of plants, the greatest stimulating effect on them was the application of mineral fertilizer, as well as the use of Ecohum complex on virginal plants and 5 % MaKloR on generative ones. As we moved north, there was a noticeable increase in the positive effect of the tested fertilizers on the formation and functioning of the microbiota of the root zone of the late-ripening cranberry variety, the greatest efficiency of using exclusively biological fertilizers, especially bacterial MaCloR in a 10 % concentration on virgin plants and 5 % on generative ones.

The influence of the main physiological groups of soil microorganisms on transfer of ¹³⁷Cs from the peaty-gley soil into the biomass of oats (Avena sativa L.) are analyzed in the article. The soil contaminated with radioisotopes after the Chernobyl nuclear power plant accident. The impact of these groups of microorganisms on the content of stable isotopes K, Ca, Sr, Cs in bioavailable forms in the soil are is presented as well. 1 It was established that the introduction of phosphate-mobilizing bacteria and spore-forming ammonifiers into peaty-gley soil did not change the level of ¹³⁷Cs accumulation in the aboveground biomass of oats. However, both groups of soil microorganisms significantly (by 44‒84 %) increase the content of radioactive and stable isotopes of cesium in water-soluble form in the soil.

Against this background, the introduction of phosphate-mobilizing bacteria into peaty-gley soil reduces the accumulation of radionuclide in the roots of the plant by 30.5 %. The absence of increased accumulation of ¹³⁷Cs in oats with increase in the content of radionuclide in water-soluble form is explained primarily by an increase in the content of К in bioavailable form in peaty-gley soil when phosphate-mobilizing bacteria and spore-forming ammonifiers are added to it.

The article analyzes the genetic diversity of populations of Lobelia dortmanna L. (Dortmann’s lobelia) performed using molecular iPBS markers. All known populations in Belarus from lakes Beloye (Luninetsky district), Svityaz (Novogrudsky district), Belyanets and Bredno (Rossonosky district), located in island localities far from the south-east border of the range, were studied. The research results showed that Nei’s greatest genetic distance is characteristic of the Belyanets population (0.15), and the least one is characteristic of the Bredno population (0.10). For this species, no relationship has been identified between the position of the population within the range, its size, plant vitality and the level of genetic diversity.

For Belarusian populations of Lobelia dortmanna L., a predominance of interpopulation variability (54 %) over intrapopulation variability (46 %) was established, which indicates a high level of their genetic differentiation. The gene flow for populations of the species under study is 0.35, which confirms the low level of gene exchange between populations and is consistent with an extremely low population size of the species in the territory of Belarus, as well as the isolation of populations both from the main fragment of the species’ range and among themselves. Data of the cluster analysis of Lobelia dortmanna L. populations demonstrate their division into 2 genetically distinct groups, the geographical location of which confirms their genetic connection with the Fennoscandian and Atlantic-European fragments of the species’ range in the northern part of Europe.

Recently, along with the determination of physical and chemical pollution in establishing the quality of surface waters and especially river ecosystems, the biological and, first of all, the hydrobiological component has become increasingly important. The purpose of this work was to assess the ecological quality of river ecosystems in specially protected natural areas of Belarus and Uzbekistan based on the study of the macrozoobenthos community.

Alien, rare for Belarus and protected in Europe, species of aquatic organisms were identified at the model stations.

In the territory of the both states, a high abundance (from 30 to 80 %) of rheophilic species Plecoptera, Ephemeroptera and Trichoptera, which represent the three most priority indicator groups of aquatic organisms, was noted. Biotic indices were determined and the class of water purity of the rivers of the State landscape reserve “Srednyaya Pripyat”in Belarus and the Ugam-Chatkal State Natural National Park in the territory of Uzbekistan were calculated. In accordance with the EU Water Framework Directive, the ecological water quality at the studied sampling sites can be classified as good and high water purity classes in the territory of the both countries.