Among the large number of harmful and common fungal diseases of flax, anthracnose is one of the dominant ones. There are no highly resistant varieties to this pathogen in production. The search and formation of a collection of diverse sustainable flax material is one of the tasks of the modern selection, which was the purpose of our work. Laboratory and field studies using a synthetic population of anthracnose pathogen to determine flax resistance to the pathogen were conducted in the Northwest area of the Tver region. The object of research were collection samples from the “National Collection of Russian flax” of the Federal Research Center for Bast Crops, flax selection lines obtained by biotechnology and the bio samples of the anthracnose pathogen from the “Collection of microorganisms - pathogens of major flax diseases”. Over the years of research (2019–2023), the "Collection of microorganisms - pathogens of flax diseases" has been replenished with 41 biological samples of the anthracnose pathogen. The dominant position was occupied by highly virulent strains – 55.6%, weakly virulent biological samples made up 18.4%. Screening of 384 collection flax samples against an infectious background revealed a low content of resistant samples, only 36 samples were relatively resistant (50.0–68.0%), and 90.6% of the collection samples were susceptible. 7 genotypes were identified, showing relative resistance to the pathogen at the level of 60.1–68.0%: G-60505-9, D238/2/15/119-13, D14/No.3896hAR6, L-2897-6-6, 0-15247-6-13, 0-15157-7-5, K-3774*. The breeding lines NP_r-1-7 and NP_r-2-3 of fiber flax, obtained as a result of using biotechnological methods, have confirmed their resistance against an infectious background, in the field (61.1–75.0%). No highly resistant flax samples to anthracnose have been identified. The use of 9 sources characterized by resistance at the level of 60.1–75.0% in the breeding program will increase the efficiency of breeding work to create disease-resistant flax varieties.

The results of the studies of photosynthetic activity of the seedlings of spring soft wheat three varieties and their adaptive responses to the combined effect of infection with the pathogen of common root rot of cereals Bipolaris sorokiniana Shoem. (B. sorokiniana) and chloride salinization on the parameters of chlorophyll fluorescence (ChlF) are presented. The seedlings were grown from pathogen-infected 3-day-old germinated seeds on sodium chloride solution (experiment) and on tap water (control) under specified climatic conditions. ChlF was recorded in 10, 12, 14, and 16-day-old seedlings using a Dual-PAM-100/F fluorimeter in a Slow Kinetics mode. The studies were carried out in 2022, 2023. The informativeness of the ChlF parameters Y(II), ETR, qP, Y(NPQ), qN and Y(NO) as biomarkers of photosynthetic activity and assessment of the resistance of the varieties to the combined effects of B. sorokiniana and chloride salinity was confirmed. The F_v /F₀ and F_v /F_m parameters turned out to be less sensitive. The maximum significant intervarietal differences (from 1.8 to 4.3 times) were detected in six parameters of the ChlF. The smallest changes in ChlF parameters relative to the control were found in the more resistant variety Sibirskaya 21 compared to the less resistant varieties Novosibirskaya 41 and Novosibirskaya 29. Severe stress condition on the 16th day of cultivation of the Novosibirskaya 29 and Novosibirskaya 41 seedlings resulted in a synchronous increase in the parameter of unregulated non-photochemical quenching of ChlF Y(NO) by 45.8 and 59.9% and a decrease in the parameters of the regulated photochemical quenching Y(NPQ) and qN from 44.5 to 58.9%, respectively. This indicates a decrease in the efficiency of protective regulatory mechanisms during photosynthesis, which can serve as a diagnostic indicator in assessing the stress tolerance of varieties. It is concluded that it is possible to use ChlF parameters to assess photosynthetic activity, identify adaptive components and phenotyping of wheat varieties for resistance under the combined action of B. sorokiniana and chloride salinity.

The influence of meteorological conditions of the region on the duration of the vegetation period and production process of domestic and foreign soybean breeding was determined. The research was conducted in the period 2021–2023 in the Bryansk region. 18 soybean varieties included in the Register of breeding achievements admitted to use were taken as an object of research. According to the duration of the vegetation period varieties are divided into three groups of ripeness: fast-ripening – Vita, Lira, Leader 10, Amadea, Lisbon, Vera, early-maturing – Protina, Volma, Kora, Zusha, Mezenka, Osmon, Sultana, medium-maturing – Sculptor, Pripyat, Puma, Sirelia, Ros. It was revealed that, on average, plant height increased with the increasing vegetation period: fast-ripening – 75.8 cm, early-maturing – 77.3, medium-maturing – 83.0 cm. It was revealed that, on average, with an increase in the growing season, the height of plants increased: precocious – 75.8 cm, early-maturing – 77.3 cm, middle-maturing – 83.0 cm. 4 genotypes (22 %) with low attachment of the lower beans were identified: Vera, Kora, Pripyat, Sirelia, 11 varieties (61 %) with medium attachment of the lower beans: Vita, Lira, Leader 10, Amadea, Lisbon, Volma, Zusha, Osmon, Sultana, Sculptor, Puma, 3 varieties (17 %) with a high attachment: Protina, Mezenka, Ros. The weight of 1000 seeds was calculated – varieties with larger filled seeds: Sultana (176), Ros (177), Lisbon (162), Vita (158), Vera (158), Sirelia (158). Varieties with the highest seed yield were identified: Ros (25.3 c/ha), Zusha (22.8), Sculptor (22.2), Pripyat (22.2), Lisbon (22.1 c/ha). Crude protein was determined by the Kjeldahl method, crude fat by the Soxhlet. The high content of crude protein was formed by the varieties of domestic breeding: Puma (36.66%), Mezenka (35.95%), Osmon (35.75%), Vera (35.34%); foreign varieties: Sirelia (39.05%), Sultana (38.27%), Pripyat (36.17%). The crude fat content in the seeds varied both by year and by variety. The maximum fat value was noted in the genotypes: Ros (23.78%), Mezenka (23.72%), Sculptor (23.18%), Zusha (22.45 %), Sultana (22.36%).

The results of the study of 20 samples of cultivated flax (Linum usitatissimum L.) of the Federal Scientific Center of Bast Crops in 2021–2023 are presented. The field studies were conducted in the sub-taiga zone of the Tomsk region. Natural and climatic conditions corresponded to the requirements of fiber flax cultivation. As a result of the conducted research, valuable and flexible source material for the creation of varieties with high productivity traits has been identified. The varieties of the Pskov selection – Antey, Voskhod, Nord, Chance, Tver (Torzhok) selection – Polet, Universal, Smolensk selection – Phoenix, Impulse and standard Pamyati Krepkova – stood out in terms of total and technical length of the stems. The total stem length reached 90 cm and above, the technical stem length was more than 80 cm. The leaders in terms of fiber content in the technical part of the stems were varieties of the Tver selection (Torzhok): Tonus, Visit, Pskov varieties – Kvartet, Orion, Peresvet – 40% and higher. The highest value for the characteristic of stem slenderness (the ratio between technical length and stem thickness) was observed in the varieties Voskhod (681.0) and Peresvet (652.6). In terms of linear stem density, the varieties differed insignificantly among themselves, with most varieties having values in the range of 5.0–6.0 mg/cm. The influence of the factor " The year of inclusion in the State Register of BA of the Russian Federation" was also studied. The factor had the greatest influence on the fiber content trait. Varieties with earlier dates of inclusion in the State Register showed low fiber yield. Russian flax varieties are recognized as promising and are included in the breeding process as male and female seed parents during hybridization.

The priority direction in potato breeding in the Magadan region, given the short growing season and heat shortage, is the creation of predominantly early-ripening potato varieties. The article presents the results of the evaluation of potato breeding samples in terms of productivity and ripeness. Over two years, about three thousand samples of 67 hybrid combinations have been studied. The research was carried out in 2022–2023 on the experimental field of the Magadan Scientific Research Institute of Agriculture on floodplain, sod-alluvial, pebble-sandy loam soils. More than two thousand samples represented by 25 hybrid combinations were studied in the nursery of seedlings. Hybrid combinations characterized by a high frequency of selection of promising forms are identified, such as Arctica × Elbeida, Udacha × Bellarosa, Krone × Bellarosa, Charoite × Bellarosa, Krone × Labadia, Arctica × Gala. In these hybrid combinations, from 7.6 to 17.9% of the samples from the total number of the seedlings planted in the field were selected as clones. The samples with high productivity indicators were selected in the nursery of hybrids of the 1st year. The maximum weight of tubers of one plant was noted in the populations of Columba × Krepysh – 2010, Udacha × Bellarosa – 1820, Arctica × Elbeida – 1825, Charoite × Bellarosa – 1800. In the nursery of hybrids of the 2nd year, hybrids with productivity exceeding 1000 g/bush, such as Columba × Krepysh (2700 g/bush), Udacha × Bellarosa (1950 g/bush), Arctica × Krepysh (1670 g/bush), were identified in terms of yield and economically valuable characteristics. The frequency of selection of productive clones here exceeded 50%. These hybrid combinations are recommended for breeding research in the conditions of the Magadan region.

In recent years, one of the problems associated with introduced woody plant species has been the invasion of pests and diseases into their secondary habitats. Such an invader in Russia, including the Far East, is Robinia pseudoacacia L. In order to assess the distribution of pests of this species in the south of the Far East and to evaluate the damage caused by them, monitoring of plantations in populated areas of the region is necessary. The article provides data on the distribution of pests R. pseudoacacia – Euura tibialis (Newmann, 1837) (Hymenoptera: Tenthredinidae), Obolodiplosis robiniae (Hald.,1847) (Diptera: Cecidomyiidae) in the Primorsky Territory. Studies of the R. pseudoacacia plantings show that E. tibialis occurs in 9 of 24 localities. On each plant specimen, approximately 2–3%, in some cases up to 4%, of the leaf plates were damaged to a greater or lesser extent. The northernmost point of the pest distribution is the town of Luchegorsk, the southern point is the Slavyanka settlement. The most affected are the city of Ussuriysk and the village Sinij Gay. A pest such as O. robiniae is found in all the 24 surveyed settlements. The northernmost point of its distribution is the city of Luchegorsk, the southernmost point is the Hassan settlement. The most affected by this pest is the town of Artem, the town of Bolshoi Kamen, Khorol settlement, Tavrichanka village. Further monitoring of R. pseudoacacia plantations in the Primorsky Territory is necessary in order to determine the distribution of its pests and assess the damage they cause.

Selection and accompanying inbreeding are the basis for breeding chicken breeds. With the advent of modern molecular methods for assessing inbreeding, it has become possible to identify genes and their functions in the homozygous regions (ROH) of chicken chromosomes. In this study, a genome-wide analysis of homozygous regions of chromosomes in Italian partridge chickens was carried out using an SNP chip Illumina Chicken 60KSNPiSelectBeadChipchip. An average of 177 ± 5 ROH-sequences per chicken were identified in the chicken chromosomes, and the average inbreeding coefficient was 0.30 ± 0.01. It was determined that the chicken genome is dominated by short ROH-sequences of 0.25–2 Mbp. ROH-sequences longer than 8 Mbp indicating recent inbreeding account for no more than 2.2%. It was found that, in general, ROH-sequences are more densely distributed in chicken microchromosomes, with the exception of chromosome 16, which does not have ROH-sequences. This fact is due to the heterozygosity of the alleles of the genes responsible for immunity, located in microchromosome 16. ROH-islands were found in the chicken chromosomes 1, 5, and 14. The genes in ROH-islands are responsible for feather pecking in chickens (DMD gene), immune status (TAB3, EIF2S3 genes), body weight (IL1RAPL1 gene), pH of meat (EIF2S3, APOO, KLHL15 genes), egg production (APOO gene), feed uptake (SAT1 gene), aggressiveness of roosters (SLITRK6 gene), transport of intracellular components in developing neurons and protection of heterochromatin in the cell nuclei of neurons (NDE1 gene), adaptation of chickens to tropical living conditions (CDIN1 gene). Thus, ROH analysis allowed us to identify genes potentially selectable as a result of breeding Italian partridge breed chickens.

219 samples of biological material from animals and 54 samples of environmental objects from farms in the Novosibirsk region, which are free from bovine tuberculosis, were examined for isolation of the tuberculosis pathogen, microbiological and genetic typing of isolated cultures of atypical mycobacteria. Microbiologic diagnosis included culture method, biochemical tests and biological assay. During the treatment of animal biomaterial 50 cultures were isolated, and 20 cultures were isolated from the environmental objects. The isolated cultures were classified as mycobacteria on the basis of their culture and morphological properties and bacterioscopy. According to biochemical characteristics, out of 70 cultures studied, 27 isolates (38.6%) belonged to atypical mycobacteria of different species. Of these, 26 cultures (96.3%) were categorized as Group III and 1 culture (3.7%) as Group IV according to Runyon's classification. Next, a biological assay was performed by infecting nonlinear white mice with suspensions of 27 identified cultures of atypical mycobacteria. At autopsy and pathological-anatomical study of laboratory animals, changes in internal organs characteristic for tuberculosis were not found, which confirms that the cultures under study belong to atypical mycobacteria. Molecular systematization of the isolated cultures revealed the presence of Mycobacterium avium (20 cultures, 74%), M. nonchromogenicum (5 cultures, 18.5%), M. intracellulare (1 culture, 3.7%) and M. fortuitum (1 culture, 3.7%). Thus, based on the results of a comprehensive study of 70 cultures of atypical mycobacteria isolated from animal biomaterial and environmental objects from the territory of farms in the Novosibirsk region, free from bovine tuberculosis, 27 isolates belonging to atypical mycobacteria of groups III and IV were identified according to Runyon’s classification. On the basis of typing, it was found that the leading role among the identified pathogens is occupied by atypical mycobacteria of group III, in particular M. avium. The etiology of nonspecific tuberculin reactions in tuberculosis-free herds of cattle can be explained by the isolation of atypical Mycobacterium tuberculosis groups III and IV according to Runyon classification from environmental objects and their persistence in the organism of healthy animals.

The analysis of morphological variability of the initial stock within the breed type Sarboyan carp (Cyprinus carpio L.) by the principal component method is presented. The research was conducted in 2022, 2023 in the Novosibirsk region. The Sarboyan carp stock (males and females) from the fish breeding farm was studied according to eight valuation measurements: body weight, absolute body length, body length without tail fin, maximum height, width and girth. A comparative analysis of the body features of the Sarboyan carp belonging to four haplotypes (H1, H15, H16, H17) was carried out. The morphometric features of the Sarboyan carp were processed using principal component method. It was found that sexual dimorphism was noted on the basis of total size: females have larger sizes than males. In the fish stock under study, a trend towards the difference between H1 and H16 haplotypes was established. The individuals in the H1 haplotype are relatively thicker and shorter compared to H16. There is a group of fish with unknown haplotypes in the data structure, all of which show a shift towards the third component relative to H1, i.e. they have a higher back and smaller body thickness. No haplotypic differences were found in the component showing an apparent inverse relationship between head length trait, body length and absolute fish length. Multivariate analysis of morphological variability also showed that distribution of the individuals in the three-dimensional space PC2-PC3-PC4, free from size-age variability, allows pre-selection of fish with the required proportions of morphological features for further reproduction.

The correlation of the Tsigai breed ewes’ gestation period with the patterns of growth and development of the sheep growing stock during the suckling period was explored in the article. The dates of inseminations and calvings were selected for analysis to calculate the duration of ewes' gestation and indicators of live weight of young animals at birth and at weaning with subsequent calculation of correlations between these traits. The average duration of the ewes’ gestation period is 157.76 ± 0.61 days (Cv=7.6%). The single-born ewe lambs of the No. 01684 line were higher in live weight by 6.9% (р ≤ 0.001), and higher in average daily gain by 6.0% (р ≤ 0.001) than the sample averages at weaning. The single-born ram lambs the No. 80077 line have a significant advantage in terms of live weight at weaning by 9.1% (р ≤ 0.01), and in terms of average daily gains by 11.8% (р ≤ 0.05). Single-born ram lambs of the No. 01684 and No. 66796 lines with a reduced live weight at birth grow more intensively: a significant advantage in terms of live weight at weaning and average daily growth, respectively, is 12.1% (р ≤ 0.001) and 9.6 % (р ≤ 0.01) higher in comparison with the average sample values. Twin ewe lambs of the No. 80077 line with a lower live weight at birth by 0.2% and an increased weight at birth by 0.4, the difference of which is also not reliable, nevertheless have a significant advantage in average daily growth compared to the average – by 9.1% (р ≤ 0.001), while the twin ram lambs have no significant difference in the indicators of the suckling period. Milkiness is negatively associated with the duration of pregnancy of ewes and positively with the lambs live weight at weaning period. In order to establish a line for increased multiplicity, it is necessary to select ewe lambs to be used in the replacement stock from twin litters in the line No. 80077. The increased live weight of young animals from single litters is formed by the parent livestock of No. 01684, 20832, 65204 and 80077 lines. The advantage of twin ram lambs in terms of live weight over the average values has not been proven.

The results of the study of selectable traits, exterior-constitutional features of medium wool sheep of the Aginskaya breed of the Zugalay type are presented. The data of correlation-regression, variance analysis are given, according to the results of which paired and multifactor regression models have been designed. Body weight (6.4–12.6%), down length (19.3–19.7%) and awn length (13.1–16.9%) and cannon bone girth (9.1%) are characterized by the greatest variability in the studied sheep. In terms of physique indices, rams are distinguished by longer legs, better breast development, stronger bones, ewe lambs are distinguished by a more stretched, bunched and massive body with a better developed hind part. Correlation analysis of the breeding traits with external body parts indicates that live weight and wool clip in rams has a closer correlation with linear measurements in comparison with ewe lambs. In both males and females, live weight was more strongly correlated with the width in the dippers, wool clip – with the width at hips in rams, in ewe lambs the relationship was weak or practically absent. Linear regression coefficients indicate that live weight and wool clip gain in rams are predicted by an increase per unit in hip width (4.37 abs. gain; r = 0.824; p < 0.001 and 0.13 abs. gain; r = 0.792; p < 0.001). The coefficient of determination showed that in rams the changes in live weight and wool clip by 67.9 and 62.8% were explained by the width at hips, the influence of other factors – 32.1 and 37.2%, respectively. In multifactor regression models, 90.3 and 78.0% of changes in body weight and wool clip in rams are explained by the influence of a complex of linear measurements, in ewe lambs – by 25.7 and 17.5%, respectively, the remaining share is attributed to the influence of other factors, respectively.

Based on the materials of long-term field observations in the southern regions of the Omsk region, the influence of the main factors on the winter movement of moisture in arable soils of the Ishim steppe was traced. The penetration depth of 0 °С determines the lower boundary and vertical thickness of the moisture freezing layer. The distance between its lower edge and the penetration depth of 0 °С is 20–40 cm. The penetration depth of 0 °С is predetermined by the air temperature and the thickness of the snow cover and reaches 170–240 cm. The forms of moisture dominant in the soil are associated with the granulometric composition. Film moisture prevails in the heavy loamy, highly silty soil-ground strata of the Ishim steppe. The content of capillary-backed and free gravitational water does not exceed 6% of the soil volume at full moisture capacity, which determines the small volume of moisture freezing (up to 50 mm). Thermogradient migration of moisture is determined by field methods in highly moistened soil-ground strata. High humidity of the soils and rocks of the Ishim steppe is associated with their granulometric composition and the close occurrence of groundwater. If in the second ten days of October groundwater is recorded at a depth of less than 3 m, the layer of moisture freezing at the end of March is noted in the depth range between 40–80 and 160–200 cm, the volume of cryogenic accumulation is 30–50 mm, including in the upper meter layer – 10–25 mm. If groundwater is detected at a depth of more than 3 m in the autumn, the freezing layer is fixed at 80 to 160–200 cm, the moisture gain in it is 15–30 mm, in the 0–100 cm layer the moisture content does not change. The role of cryogenic accumulation in replenishing the post-vegetation moisture deficit in the root layer of spring grains is modest. This process is significant for the formation of conditions for anaerobiosis and the development of modern hydromorphism in the lower soil horizons and in the subsoil strata.