In the present study, we analysed the social behaviour of a family group of bush dogs, Speothos venaticus (Lund, 1842), at Moscow Zoo. A unique situation has developed at Moscow Zoo, which makes it possible to observe a family group of bush dogs, consisting of 23 individuals. The group consisted of the parent couple and five litters of cubs (10 males and 11 females). The study was carried out in the summer and autumn of 2022 by observing a focal group of animals of different sex and age, consisting of 12 individuals (5 females and 6 males). The hierarchical structure of a group of bush dogs, the ratio of various forms of social behaviour of animals, as well as the nature of their aggressive interactions were evaluated. It was shown that in the studied family group, the dominant parent couple and their off spring were distinguished, which corresponds to the data known from the literature. The predominant form of behavior in animals was group movement around the enclosure, which accounted for 47.3% of all social interactions between dogs. The level of aggression was low among older individuals. Probably, the hierarchical structure of the group of bush dogs is not based on the aggression of high-ranking individuals, but on the demonstration of submission by low-ranking ones. Other social interactions observed included play, communication, marking, parental, and sexual behaviour. There were sex differences in the way territory was marked with urine. Females marked territory by adopting a standing posture on their forelegs, while males sprayed urine. At the same time, sequential urinary marking prevailed (71.6%).

The authors studied the effect of manganese on calcium metabolism at the level of the enteral and internal environment of the body in an experiment on rabbits. Two groups (control and experimental) of rabbits selected by the paired-analysis method were used in the experiment. There were three animals in each group. The animals in the experimental group were given a diet containing three times the amount of manganese. At the end of the experiment, blood was collected from various parts of the digestive tract of all animals under general anaesthesia. Organs and tissues werecollected for analysis after control slaughter, and the intestines were removed, followed by sampling of chyme and mucosa from the walls of various sections. The chyme was separated into fractions using the developed method. The concentration of manganese and calcium in intestinal chyme and its fractions, in mucosa of the intestinal wall, in the blood flowing in and out of the digestive tract, in organs and tissues was determined by the atomic absorption spectrophotometry method. It was shown experimentally that when the concentration of manganese in the diet of rabbits was tripled, the element was not accumulated in the internal environment but was accumulated by endogenous structures of the chyme and the mucous membrane of the wall of the small and large intestines. A metabolic change in calcium metabolism was revealed when manganese was tripled in the diet: its concentrations in the blood flowing from the intestines and in the mucous layer of the small intestine wall decreased. As a result, there was a significant decrease in bone concentrations and a downward trend in liver and kidney concentrations. The antagonistic effect of manganese on calcium metabolism in the enteric and internal environment is concluded. In the interaction of elements, the leading role of endogenous structures of chyme is noted due to ion-exchange properties of glycoproteins of intestinal cavity mucosa.

In recent years, pathogenic forms of Candida albicans have been activated and isolated in aquariums of commercially valuable fish and in closed water systems (CWIs). They largely colonise the digestive tube and lead to the death of 95‑100% of fish. Treatment methods for aquarium fish bred for food purposes are ecologically and economically unjustified, as the preparations retain a certain toxicity. In this regard, it is necessary to search for environmentally friendly methods of prevention and therapy of candidaemiasis in aquariums and CWIs. It was found that propolis in complex with methylene blue promotes complete elimination of toxicity and suppressive action of sensitizers, inhibition of increased reproduction of Candida in the organism of Oreochromis niloticus, strengthening of haematopoiesis processes, increase of neutrophils, monocytes and activation of phagocytosis. In comparison with the data of the infected fish of group 2, the level of neutrophils increased by 1.63, 1.6, 1.82 and 1.67 times, monocytes by 1.94, 2.58, 3.08 and 3.1 times on the 7th, 14th, 21st and 30th day of the experiment. This contributed to the restoration of the functional activity of cells and phagocytic reactions in the organism of O. niloticus, increasing the ecological environment, productivity and quality of the obtained dietary protein, meat rich in essential fatty acids omega‑3 and -6.

The Altai Territory occupies a leading position among the constituent entities of the Siberian Federal District in terms of arable land, of which more than 80% are located in the zone of unstable moisture. Irrigation is the predominant form of agricultural hydraulic reclamation in the region. The area of irrigated land is about 69 thousand hectares, of which almost 10% of the area has varying degrees of salinity in the 0‑100 cm layer. Prolonged irrigation and non-compliance with irrigation technologies can lead to salinisation of land. In the Russian Federation, all irrigation systems havecommon rules for collecting data on soil condition, conducting soil salinity surveys and laboratory processing of field research material. The analysis of irrigated agricultural land by the degree of its salinisation was carried out according to the data of the land reclamation cadastre for the period from 1 January 2013 to 1 January 2022. A model of the dynamics of highly and very highly saline areas was built, statistical estimates of the quality of the model were checked, and the average annual rate of increase in the area of saline areas was determined. The most likely causes of salinisation in irrigated areas were analysed. These are high groundwater levels and groundwater salinity, and high salinity of water used for irrigation. An analysis of the most likely causes of salinisation in irrigated areas was carried out, including high groundwater levels and salinity, and high salinity of water used for irrigation. The dynamics of areas with different groundwater levels, different salinities of groundwater and irrigation water are given. Based on the data from the beginning of 2022, a cluster analysis of the regions of the Altai Territory was carried out according to the degree of salinisation of agricultural land. The quality of the clustering was checked.

The article presents the results of the study of the influence of agro-ecological factors on the content of mycotoxins in the green mass of white mustard (Sinapis alba) and the spring wheat variety Lyubava (Triticum aestivum L.). The study was conducted at the experimental field «Yuzhnoe» of the Ecological Station of the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy using chemical and microbiological methods. Agro-ecological factors were evaluated by the following parameters: humus content, soil acidity, phosphorus, potassium and lead content. The immunoenzyme method was used to determine the content of mycotoxins in the vegetative mass of white mustard and spring wheat (according to development stages). As a result, the highest levels of mycotoxin contamination were found in the mid-ripe stage of the crops, exceeding the average level of contamination by 8‑11 times in wheat and 4‑5 times in white mustard. The highest inverse correlation was found between the Alternariol content in the studied crops and the soil temperature of the upper layer of the humus horizon of 0‑5 cm. This fact justifies a more detailed study of the effect of this environmental factor.

The article presents the results of a comprehensive study of Medicago falcat L. – a widespread fodder plant of the natural flora of Siberia. The aim of the research is to find out the fodder value of the species, its adaptability to different botanical and geographical zones of Siberia, as well as its stability and self-restoration ability under anthropogenic influence. To this end, the ontogenetic structure, morphometric parameters, and seed production of 15‑25 middle-aged generative individuals, as well as the chemical composition of fodder samples, were studied in 13 cenopopulations of M. falcata. The study of the fodder value of M. falcata in a wide ecological and geographical range showed that the protein content in air-dry matterdiffered from region to region: in Khakassia – on average 22.9%, in the Altai Republic – up to 15.9%, in the Novosibirsk region – up to 14.33%. One kilogram of alfalfahay contains from 0.47 to 0.67 feed units. It was found that the long life cycle of M. falcata in different botanical-geographical zones can take place in different variants, depending on the level of anthropogenic influence. Taproot plants are more common in undisturbed phytocenoses, whereas in phytocenoses exposed to anthropogenic impacts, rootstock taproot plants are predominant. Consequently, anthropogenic factors influence the number and biomass of species, the mode of seed regeneration and the ontogenetic structure of M. falcata conopopulations.

Rough elm is one of the main forest-forming species of Kashar forestry of the Rostov region. The aim of the research is to study the changes in the main inventory indicators (height, diameter, volume, increments, etc.) of the rough elm at different age periods. The study of the growth course of the rough elm in the dry bayrachny oak grove is of scientific and practical significance, since this tree species is used for the needs of the national economy not only in the Rostov region, but also in other regions of the Russian Federation. During the study of the growth course of the trunk of the rough elm, the methods generally accepted in forest inventory were applied. Enumerative inventory was carried out on the established trial area and the estimated inventory indicators (height and diameter) of the model tree were determined. After cutting down the model tree, its height, the length of the crown and the branchless trunk were measured, the places of taking cuts were marked in the middle of 2 m sections, at the base of the trunk, at a height of 1.3 m, and at the base of the vertex. In the course of the office processing, the tables of the growth course in diameter, height, volume and increment were compiled, as well as the graphs of the changes of the main inventory indicators in absolute values. The analysis of the data obtained showed that the rough elm has grown steadily over 34 years according to the main inventory indicators (height, diameter, volume), the values of increments vary. The reliability and correctness of the obtained regression equations of the growth course of rough elm (in height, diameter, volume) in the dry bayrachny oak grove is confirmed by the high value of the approximation coefficient (R² = 0.99).

The problems of morphogenesis’ induction from isolated leaf explants of the variety Georgia Plum of Heuchera hybrid were studied for the first time. The induction of callus and of adventitious shoots from leaf explants on the modified MS medium containing 30g/l glucose was carried out in the presence of 6-BAP in combination with one of the auxins IAA, IBA, NAA or 2,4-D. The cytokinin: auxin ratio in the medium was 10:1 or 20:1. The best regeneration of Heuchera hybrid (up to 92% of regenerating leaf discs) was obtained on media containing 6-BAP at a concentration of 4.0 mg/l in combination with NAA at a concentration of 0.2 mg/l or 0.4 mg/l. In this case, the number of adventitious shoots per regenerating disc could reach 7‑9 and more. The maximum frequency of direct regeneration was observed on media containing IBA. Abundant callus formation was observed on media containing 2,4-D.

This article provides an overview of modern genetic technologies for improving production traits and predicting breeding value in beef cattle. In particular, in marker-assisted selection the most promising is the selectionby desirable genotypes in the genes of myostatin (MSTN), calpain (CAPN), calpastatin (CAST), growth hormone (GH), leptin (LEP), thyroglobulin (TG), fatty acid binding protein (FABP), retinoic acid C-receptor (RORC), diacyl-glycerol acyltransferase (DGATI), sterol-Co desaturase (SCD). A modern and much more advanced approach is the Single Step Genomic Best Linear Unbiased Predictions (ssGBLUP) method, which calculates a Genomic Estimated Breeding Value (GEBV) using DNA chip genotyping, phenotype and pedigree data. Genome-wide association studies (GWAS), based on the use of genetic markers distributed throughout the genome and in non-equilibrium linkage with at least one of the quantitative traits, are currently recognised as more informative for finding new genes for beef cattle productivity. New genes associated with live weight at different stages of ontogenesis, average daily live weight gain, residual feed intake, carcass weight and flesh content have been identified. Most of the identified genes control cell division, lipid and carbohydrate metabolism. The accumulated data on full-genome association studies and exome sequencing led to new methods of genetic analysis – gene ontology and gene networks. The use of gene networks provided the first detailed understanding of the genetic basis for the formation of complex phenotypic traits based on the complex interaction of regulatory networks of «major» and «peripheral» genes controlling the development of a particular trait.

Nanoparticles (NPs) are materials with unique physical and chemical properties that are less than 100 nm in size. They are widely used in various fields of industry, medicine and agriculture. In agribusiness nanomaterials are used as nanofertilisers and nanopesticides. This fact requires a detailed study of the physiological, biochemical and molecular genetic responses of cells of living organisms – plants, fungi and animals – to interaction with nanomaterials. This review article provides information on the mechanisms of nanoparticle absorption, movement and molecular interaction in plant organisms, as well as mechanisms of their antibacterial and fungicidal activity. Available scientific resources devoted to the physiological features of nanoparticle absorption by plants indicate two possible ways of their penetration into the plant organism – apoplastic and symplastic. In plant cells, nanoparticles act as reactive oxygen species (ROS), causing oxidative stress and triggering enzymatic and non-enzymatic defence systems that result in both inhibition of physiological processes and stimulation of plant growth and development and, consequently, increased yield. The effect on the plant organism is species-specific and depends on the type of nanomaterial and its concentration. Detailed laboratory and field studies are required to determine the specific effect of nanomaterials on a particular plant species, while complying with all toxicological safety standards to avoid environmental contamination with nanomaterials. Nanoparticles act on microorganism cells as physical and chemical disruptors – they change the permeability of cell walls and organelle membranes, protein configuration, damage DNA, leading to physical destruction of cells. Such properties of nanoparticles define antimicrobial and fungicidal activities of nanoparticles. However, nanoparticles should be used cautiously in crop production, as both plant life and productivity depend largely on microbial symbionts, and their effect on microbial cells is not species-specific.

In order to find out the relationship between the level of nitrogen nutrition of oat plants of the Yakov variety and the content of amino acids in leaf juice, as well as the possibility of using this indicator to assess the content and composition of proteins, the activity of amylases, catalases and peroxidases in ripe grain and the activity of theseenzymes in germinating grain, a field experiment was carried out at the Field Experimental Station of Russian State Agrarian University – Moscow Timiryazev Agricultural Academy, on sod-podzolic medium loamy soil. In the field experiment, variants with different levels of nitrogen nutrition of oat plants that had passed post-harvest ripening were tudied. Ammonium nitrate, double superphosphate, and potassium chloride were applied in advance. As a result, it was found that as the level of nitrogen nutrition of plants increased, the concentration of amino acids in the juice of oat leaves at the stage of formation of the first stem node decreased, which was closely correlated with the nitrogen doses. These data indicate the possibility of using this indicator for the diagnosis of nitrogen nutrition in oat plants. The studies also revealed a reliable correlation between the content of amino acids in leaf juice and the concentration of proteins soluble in water and solutions of 10% KCl, 0.2% NaOH, as well as the activity of acid (pH 5.5), neutral (pH 7) and alkaline (pH 8) isoenzymes of α-amylase and acid isoforms of β-amylase in ripe grain. In addition, the amino acid content of leaf juice was found to be significantly correlated with the activity of acidic α-amylase, acidic and neutral β-amylase in germinated grain. The results obtained demonstrate the possibility of predicting the level of protein accumulation in oat grains. It is also possible to predict the protein composition, activity of α- and β-amylase, catalase, and peroxidase isoenzymes from the content of amino acids in leaf juice in the phase of the first stem node formation. A reliable correlation was also found for the activity of acid and neutral isoenzymes of α-amylase, catalase, and peroxidase in ripe and germinated oat grain.