Relevance. A significant increase in microbiome-associated diseases, closely related to violations of the bacterial diversity and functions of the normal intestinal microbiota, dictates the need to develop and implement measures for the long-term preservation of individual representatives of the normal microbiota in order to create new strategies for modifying the composition of microbiomes.
Methods. The influence of the technology of deep freezing and storage of intestinal isolates of lactic acid bacteria of 2 taxonomic groups isolated from poultry in the conditions of the Low-temperature automated storage of biological samples of the Departmental Collection of useful microorganisms for Agricultural purposes of the Russian Agricultural Academy (VKSM) on the MRS culture medium using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants was studied. The suspensions of the isolates were frozen at - 150 °C for 18 hours and then placed in an automated cryopreservation at -80 °C. Control of samples for safety

Results. The technology of cryofreezing of lactic acid bacteria on MRS-broth using 10 and 20% glycerin or 10 and 20% sucrose as cryopreservants allows preserving the viability, physiological and  biochemical properties of intestinal isolates of lactic acid bacteria when stored for 18 months. All the protective media used (MRS-broth with glycerin 10 and 20%, MRS -broth with sucrose 10 and 20%) showed comparable results in the preservation of viability and acid-forming activity of Lactobacillus fermentum-2, Pediococcus pentosaceus 6p-3, Pediococcus pentosaceus 28p-1 isolates. Then the storage of Pediococcus pentosaceus isolate (28p-1) in a given parameter on a protective medium with 10 and 20% sucrose led to a decrease in the activity of acid formation.

The article discusses the option of using PCR analysis to assess the purity of the species composition of heat-treated sheep's milk. In the course of the work, the genetic material of the main dairy breeds of goats and sheep represented on the territory of Russia was studied. For this purpose, the 12S rRNA of a goat and a sheep was used as a target gene, on the basis of which a pair of primers 12SCH-DIR (5'-AAACGTGTTAAAGCACTACATC-3 ‘) and 12SCH-INV (5'-GTCTTAGCTATAGTGTATCAGCTG CA-3') for goat and 12SM-FW (5'-CTAGAG-GAGCCTGTTCTATAATCGATAA-3 ‘) and 12SOA-INV (5'-GTCTCCTCTCG TGTGGTTGAGATA-3') for sheep. The resulting primers were tested for specificity by analyzing the milk of various breeds of goats (Saanen, Toggenburg, Alpine and Nubian dairy) and sheep (Tsigai, Assaf and East Friesian). As a result of the study of binary mixtures of sheep and goat milk, it was found that the use of this method of PCR analysis makes it possible to detect impurities of goat's milk in sheep's milk at a level of 0.1%. It has also been shown that the technique is applicable to both raw milk and processed 
milk.

Relevance. Cytogenetic studies are in demand to identify carriers of hereditary anomalies. In order to obtain metaphase plates of the chromosomes of various animal species, we optimized the usual method, taking into account some adjustments.

Methods. The main research criterion was the selection of a hypotonic solution for cytogenetic studies in sheep and goats. 3 variants of using hypotonic solutions were considered: 0.56% solution of potassium chloride; distilled water and 0.56% solution of potassium chloride; 2% solution of sodium citrate and 0.56% solution of potassium chloride (1:1). For the cultivation of peripheral blood cells, blood was taken from the jugular vein of animals (goats n = 8, sheep n = 11).

Results. The cells were cultured according to the generally accepted method. The results of the conducted studies showed that the quality of the preparations differed depending on the components used. The optimal parameters for the preparation of chromosomes with a good distribution were obtained by culturing sheep lymphocyte cells using 0.56% potassium chloride as a hypotonic solution (20 min) and ranged from 14.29 to 25.00%. For cytogenetic studies in goats, optimal results were found when using a 2% solution of sodium citrate with a 0.56% solution of potassium chloride (1:1) for 20 minutes — from 13.33 to 25.00%. Each option allowed to reduce the loss of cells during the preparation of chromosome preparations for a certain type of animal. Thus, the developed protocol for obtaining metaphase plates using a 2% solution of sodium citrate with a 0.56% solution of potassium chloride (1:1) as a hypotonic solution is optimal when used in goats, while the classical method (0.56% solution of potassium chloride) was most suitable for sheep. 

In many livestock farms that are engaged in the breeding of cattle, both meat and dairy directions fresh pulp is mixed with molasses, and then this mass is given to the animals. Beet pulp is a by product of the beet sugar production process, representing desaccharified beet chips (80-82% by weight of processed sugar beet with a dry matter content of about 6.5-7%). The main direction of using sugar beet pulp is the use of it in the feeding of cattle for meat and milk directions. Beet pulp remains one of the most valuable feed for feeding cattle. Pulp is a highly digestible source of carbon, its main components are pectin and hemicellulose. At present, the issue of the quality of beet pulp plays a crucial role in its use for feed purposes. The volume of its implementation in feed production depends on it.

The article discusses the dynamics of changes in the area of the assimilation surface of assimilation organs of different genotypes of durum and soft wheat as a result of drought, differing in the ripening period. As you know, under drought conditions, the water potential of the soil first decreases, and then the plants; at later stages, the turgor pressure decreases, stomata close and there is a sharp decrease in photosynthetic activity. This situation creates stress in organisms and various biochemical, physiological and molecular reactions arise to overcome and protect this stress, allowing plants to develop resistance mechanisms that allow them to adapt to the external environment. The study showed a wide range of changes in the surface area of assimilation to assimilate organs in ontogenesis, depending on the morphophysiological characteristics of genotypes and donor-acceptor relations. Expansion of these studies showed that chloroplasts of high-yielding genotypes are characterized by high rates of electron transport and phosphorylation. It has also been confirmed that there is a relationship between CO₂ assimilation and productivity.

Relevance. Over the past decades, new and extremely virulent races have appeared in the southern regions of the Russian Federation, which overcame the resistance of domestic and foreign sunflower range of varieties. The most effective, long-term, and biologically safe way to protect sunflower from broomrape is to develop varieties and hybrids resistant to new races.
Methods. We identified broomrape seeds of race G using internationally accepted differentiator lines: Record 1-3 (C), S-1358 (D), P-1380 (E), LC1093 and P96 (F). We used sunflower lines and hybrids of the breeding of V.S. Pustovoit All-Russian Research Institute of Oil Crops as a parent material. We carried out the evaluation of broomrape resistance by the method of A.Ya. Panchenko. To develop an infectious background, we introduced seeds of broomrape race G into boxes with a soil and sand mixture at the rate of 200 mg per 1 kg of the mixture, distributing them evenly. We grew sunflower 
plants at a temperature of 25-27 °С and a 16-hour photoperiod. In 25-30 days after the emergence if seedlings, we dug up plants and counted the broomrape specimens on their roots by a scale.
Results. We developed sunflower lines resistant to races of broomrape from A to G. All of them are of branched form, with different lengths of the period from germination to flowering, they differ in height and oil content. The line L 82 is distinguished by a high content of oleic acid in oil — 91%. The lines have a high combinability. We obtained experimental hybrid combinations using these lines.

In conditions of a shortage of manure and high prices for mineral fertilizers, the preservation and improvement of soil fertility is an urgent problem of agriculture. The studies were carried out at the Prikumsk experimental selection station in two 6-field crop rotations from 1969 to 2019 The purpose of the research is to study, in a long­ term stationary experiment on various nutritional backgrounds, the effect of grain crop rotations with clean and busy fallow on the fertility of the chestnut soil in the arid zone of the Stavropol Territory. In the grain-and-row crop rotation with 16.6% of pure fallow, the decrease in the humus content in the control was 0.10%, the humus reserves were 2.6 t/ha, against the fertilized background — 0.09%, 2.3 t/ha, and with the occupied fallow on the contrary, it increased by 0.10%, 2.6 t/ha and 0.11%, 2.8 t/ha. The content of mobile phosphorus in the topsoil in the control with clean fallow increased by 1.7 mg/kg, stocks — by 4.3 kg/ha, with occupied fallow — 3.4 mg/kg and 8.7 kg/ha, and on the fertilized variant — 7.5 mg/kg, 19.1 kg/ha and 7.4 mg/kg and 18.9 kg/ha. The content and reserves of exchangeable potassium increased by 3 — 46 mg/kg and 8 — 115 kg/ha. In the crop rotation with clean fallow, they were 4.2-4.1 times lower on the control, and 13.7-13.0 times lower on the fertilized background, compared with the occupied fallow. The application of fertilizers contributed to a decrease in the potassium content in the crop rotation with clean fallow by 3.7 times, reserves by 3.5 times, and with busy fallow by only 12.2 and 10.6%. Sainfoin fallow significantly increased the content and reserves of potassium in the soil in the control and significantly reduced its consumption in the fertilized variant.

Relevance. For the development of the main branch of agriculture in Yakutia — animal husbandry, one of the most pressing problems is the availability of feed. The article presents the results of research conducted at the Yakut Research Institute of Agriculture.

Methods. Scientific research on the selection of sunflower mixtures with promising forage crops was carried out at site 30 “A“(on the basis of the laboratory of feed production of the YANIISKH) on the second over-floodplain terrace of the Lena River in 2018-2019.

Results. The results of research on the growth and development of forage crops, the formation of yield, chemical composition and nutritional value of sunflower and its mixtures with promising annual crops are presented. High indicators for the development and yield of the tested crops were provided by sunflower mixed with corn 42.7 t/ha of green mass and sunflower mixed with Sudan grass 40.2 t/ha of green mass. The terms of sowing and harvesting of sunflower and its mixtures on permafrost soils are determined — sowing — the first decade of June, harvesting-the second decade of August before early-autumn frosts in the phase of mass flowering and throwing out panicles of the tested forage crops.

Relevance. The productivity and especially the quality of flax products largely depend on a set of technological techniques that take into account varietal characteristics, agrochemical properties of the soil and the fertilizers used. Identification of the reaction to the production process of a new high-yielding flax variety of Universal is an important element of agricultural technology.

Methods. The sod-podzolic medium loamy soil is characterized by a slightly acidic reaction of the soil solution pHKCl-5.44, a very high content of phosphorus (298 mg/kg) and medium potassium (85 mg/kg), low humus — 2.05%, medium boron (0.33 mg/kg), low zinc (0.56 mg/kg). The HTC (hydrothermal coefficient) for May — August by year was — 1.56 optimal (2017), — 1.09 arid (2018), — 1.80 wet(2019).
Results. Studies have shown that the Universal flax variety has a high responsiveness to the use of fertilizers. The yield increases were: for flax straw 24 to 43%, for flax seeds from 27 to 49%, depending on the form of fertilizer and the method of their application. The advantage of the complex organomineral OMU “Universal” and mineral nitrogen-phosphorus-potassium with boron containing trace elements over the azofoska in equalized doses of nitrogen is noted. The increase in the yield of the flax stock of these fertilizers with the row method of application was lower by 40 and 34% of their main application, but the profitability of this method increased from 46 to 234% and from 62 to 219%. The application of organic fertilizer Sivid — Bor for seed treatment and Sivid-Zinc for crop processing on the background of reducing the dose of azofoski from 1.5 to 1.0 c/ha allowed to raise close to making azofoski of 1.5 c/ha, but with a greater profitability of 115%.

The article presents the results of a study on the study of the peculiarities of wheat cultivation in the extreme conditions of Karakalpakstan. The species composition of harmful insects inhabiting the wheat biocenosis has been studied. features of the use of lacewings multiplied at the biological laboratory against wheat aphids and the conditions of their reproduction in subsequent periods, with an increase in natural populations on wheat crops.

In 2 series of experiments, the influence of population density and substrates on the growth and development of microgreens in oil radish was studied. In the optimum zone were crops with a density of 5 and 7 g of seeds per container with an area of 144 cm2. At higher seeding densities, the plants lagged significantly behind in growth. Their average height was 1.5 times less, and the average mass of microgreens per 1 g of sown seeds decreased 2-2.5 times. A new inert substrate, foam glass, was tested. Possessing high porosity, it provided an optimal water-air regime for plants. Comparison of growing microgreens on soil and foam glass showed the advantage of foam glass — the mass of plants on it was slightly larger. Despite the optimal air-water regime created by the foam glass, the diameter of the stones of 1.5-3 cm turned out to be excessively large and created inconvenience for growing microgreens.