Bulletin of Polessky State University. Series in Natural Sciences

Implications of environmental factors on fishing performance of clarias Gariepinus catfish (Clarias gariepinus)

A.V. Kozyr — 2024-12-30

The influence of such environmental factors as ammonia-ammonium, nitrites, nitrates, pH, suspended solids on the main aquaculture indicators during the cultivation of Clarias gariepinus has been determined. Aquaculture techniques developed to reduce the toxicity of pollutants on the cultivation object have been tested and their technological evaluation provided.

Floristic features of the promising reserve of local importance «Telekhansky»

A.M. Mialik — 2024-12-30

Objective – to identify the floristic features of the promising reserve of local importance «Telekhansky» and to assess the conservation value of the flora of this territory. Materials and methods. The results of expeditionary floristic research, generalization of materials from herbarium collections, stock and literary data, zoological analysis of flora. Results. The article presents the features of the rare component of the flora of the promising reserve of local importance «Telekhansky», located on the territory of the Ivatsevichi district of the Brest region. The places of growth of 13 species of vascular plants with the category of protection of the Red Book of the Republic of Belarus, as well as 18 species from the list of wild plants and fungi in need of preventive protection are marked here. A total of 13 rare species have an international protected status, which indicates the high conservation value of this area. Conclusion. The revealed floristic features of the promising reserve of local importance "Telekhansky" show the significant role of this territory in preserving the phytodiversity of the central part of the Belarusian Polesie. The high number of regionally rare and nationally protected vascular plant species indicates the high diversity of the local flora and the possibility of organizing a new protected area, which is a link between the existing ecological corridors of national importance «Shcharsky" and "Yaselda». Keywords: Belarusian Polesie, protection of flora, new wildlife sanctuary, rare species.

Comparative analysis of genetic diversity of the population of some rare species of aboriginal flora of Belarus

N.V. Hudnaya — 2024-12-30

The article presents the results of a comparative assessment of the genetic diversity of some protected native plant species of Belarus. Materials and methods. Molecular genetic analysis using iPBS-markers, effective and observed number of alleles, Shannon information index, Nei’s gene diversity, gene flow between populations, distribution of genetic diversity within and between populations, results of expeditionary floristic studies. Results. Analysis of average values of genetic diversity indices of 7 populations of Cephalanthera longifolia (L.) Fritsch, 8 populations of Goodyera repens (L.) R.Br, 4 populations of Cypripedium calceolus L., 6 populations of Liparis loeselii (L.) Rich. and 4 populations of Lobelia dortmanna L. showed that the highest level of genetic diversity was noted in Liparis loeselii (L.) Rich., and the lowest in Cypripedium calceolus L. The indices of distribution of intra- and interpopulation genetic diversity, established using AMOVA analysis, as well as the level of gene flow, are consistent with the frequency of occurrence of the studied species in Belarus. Lobelia dortmanna L. and Cephalanthera longifolia (L.) Fritsch, preserved in isolated localities, are characterized by the lowest level of gene flow and a higher percentage of interpopulation genetic diversity in comparison with other species. Conclusion. Comparison of the indices of genetic diversity of populations of some rare species of the native flora of Belarus confirms their vulnerable position and can be considered as an additional criterion for assessing their conservation status and developing conservation strategies.

Characteristics of the toxicological effects of heavy metals on the physiological parameters of Daphnia Magna

A.P. Zhyvitskaya — 2024-12-30

The effects of heavy metals copper (II), iron (II), lead and nickel on the acute immobilization of Daphnia magna were studied. To build dose-effect models in this work, a log-logistic model with four parameters LL.4 of the drm library in the statistical computing environment R is used. The shapes of dose-effect curves of the immobilization of Daphnia magna in the area of the studied concentrations indicates that the effectiveness of inhibition of motor activity decreases in the range Cu2+ > Cd2+ > Pb2+ > Ni2+, which is confirmed by the calculated values of EC50: EC50 Cu2+ (0.11 mg/l) ≈ EC50 Cd2+ (0.14 mg/l) < EC50 Pb2+ (1.41 mg/l) < EC50 Ni2+ (2.84 mg/l). The effect of binary mixtures of cations on the mobility of Daphnia magna has also been investigated. It was shown for Pb2+ and Cd2+ ions at low concentrations (0.05-0.7 mg/l and 0.05-0.1 mg/l, respectively) that the addition of Cu2+ had a synergistic effect, and at high concentrations the combined effect changed to antagonistic. As for Ni2+ ions, an antagonistic effect was observed in the entire concentration range when Cu2+ was added. When studying the effects of a mixture of Ni2+ cations with Cu2+, Cd2+ and Pb2+ ions, all the studied mixtures of metal ions led to increased inhibition of the mobility of daphnia crustaceans, i.e. a synergistic effect is observed. The order of toxicity of mixtures for Daphnia magna decreased in the series Cd+Ni > Cu+Ni > Pb+Ni.

Effect of copper sulphate on the physiological and biochemical state of cells of Chlorella Vulgaris

I.A. Ilyuchyk — 2024-12-30

When adding CuSO4 to the Tamiya medium in the concentration range of 10–8–10–4 M, the Chlorella vulgaris culture retained its viability for 21 days. However, at all concentrations of copper sulfate, in comparison with the control, inhibition of biomass growth was noted, especially after the 9th day. The maximum effect - a decrease of 34–53% - was revealed at a Cu2+ concentration of 10–4 M. Changes in the concentration of intracellular protein in all variants of the nutrient medium were close to the biomass dynamics. At the same time, adding CuSO4 to the nutrient medium in concentrations of 10–8 and 10–7 M stimulated the accumulation of intracellular protein in relation to the control up to the 11th day, and on the 7th day these variants of the nutrient medium exceeded the control by 20%. The introduction of CuSO4 into the nutrient medium was accompanied by a decrease in the level of chlorophyll a accumulation by chlorella cells, and the higher the concentration of the effector in the nutrient medium, the more pronounced it was. Changes in the level of chlorophyll b in cells throughout the observation period were less pronounced compared to those of chlorophyll a. In the dynamics of chlorella culture growth, the level of carotenoids in its cells increased, especially pronounced at a CuSO4 concentration of 10−4 and 10−5 M: the level of pigments on the 15th–17th day increased by 2.3–2.7 times compared to the beginning of cultivation.

NO synthase activity of prokaryotes

V.I. Dunai — 2024-12-30

The review article presents an analysis of the results of scientific research on prokaryotic NO synthase (bNOS). The article provides a general description of NOS, the physiological role of bacterial nitrogen monoxide (NO) in both prokaryotes and eukaryotes, and methods for determining NO in prokaryotes.

Application of lighting of different spectral composition in microclonal propagation of berry and ornamental plants

M.A. Trejlib — 2024-12-30

The results of research into the impact of LED illumination on the growth and development of regenerated plants of three varieties of common lilac Syringa vulgaris L. and one variety of Vaccinium corymbosum L. in the process of microclonal propagation in vitro are presented. The average photon flux density at the level of the outer glass surface of the cultivation vessel was about 30–35 μmol/m2-s for common lilac and about 20-25 μmol/m2-s for highbush blueberry. The highest number of shoots in regenerated plants of Duke's blueberry cultivar was revealed under illumination with LED lamps of SVD2. The height of microshoots under the variant SVD1 and SVD2 was maximum and practically equal. The use of LED lights of the SVD1 and SVD2 variant allows obtaining a larger number of cuttings of high blueberry for subsequent propagation in vitro, compared to other tested variants of the spectral composition of illumination. The light wavelengths suitable for each lilac cultivar should be selected experimentally. The best result of the regenerants height index for the variety Memory of Kolesnikov was in the control lighting variant.

Priority environmental factors for increasing species diversity and the number of wild animals in residential areas of the south-west of Belarus

V.V. Dziamianchyk — 2024-12-30

Objective – assessment of the main (priority) environmental factors contributing to an increase in species diversity and the number of wild animals in residential areas of the Brest region. Materials and methods. The structure and dynamics of Tetrapoda, were assessed at 12 monitoring points in the Brest region in 2010–2023. The species composition and abundance of Tetrapoda were surveyed at permanent observation areas and survey routes using generally accepted methods for various groups of vertebrates. Land types and the ways of nature management were assessed using maps and geographic information systems. Results. Based on the analysis of cartographic materials and field surveys, human activity factors were identified that improve the habitat and have a positive effect on the composition and abundance of vertebrate species in the residential landscape. These factors together lead to the formation of a residential habitat for animals that differs from natural territories in the research region. Examples are shown when a specific factor of human activity acted as a stabilizing or trigger factor of progressive reactions in tetrapod species and general trends of specific factors during the research period using the example of Brest. Conclusion. In the current conditions of development of residential areas of the southwest of Belarus, 10 main factors of human activity are distinguished, which to varying degrees determine the formation of favorable environmental conditions in the form of settlement ways, stable stations of vertebrates of the synanthropic complex. The most significant factors were associated with changes in forest and tree-shrub types of habitats. The most specific factor is the one arising from human relationships with animal species in populated areas.