Relevance. Potato are one of the main sources of starch. Potato starch is widely used in human economic activities. The starch content in tubers, including the number of starch granules and their size and shape, are varietal characteristics. For this reason, it is important to identify potato varieties with starch grains suitable for starch production already at the early stages of breeding process.Materials and Methods. The Aim was to study the morphological structure of starch granules in cells of potato tubers belonging to varieties from different maturity groups. Eighteen potato varieties (Solanum tuberosum L.) of various breeding origin and from different maturity groups were used as the research object. The granulometric composition was determined by the method of fluorescent microscopy. The research was conducted using a CLSM 800 confocal laser scanning microscope (Zeiss, Germany) with a laser wavelength of 488 nm.Results. The research allowed us to obtain data on the morphology of variously-shaped starch granules in cells: round, oval, elongated, and irregular. The research established a direct correlation between the number of large starch grains in a cell and the time required for a given potato genotype to mature. Mid-season and medium late potato varieties were observed to have a higher starch content than varieties from the groups with earlier maturity. On average, the difference in the starch content between these groups was 1.97%. The highest number of starch grains was found in 40-70 μm cells and larger. The research identified Solanum tuberosum L. genotypes with large and small starch granules. These genotypes might be recommended for further use in the practical breeding to create high-quality varieties.

Relevance. The development of a system of molecular markers that allows identifying the genetic determinants of resistance to pathogens, as well as the typing of alleles involved in the regulation of anthocyanin accumulation, is the most important condition for increasing the efficiency of the breeding process aimed at enhancing the resistance of cultivated crops to biotic and abiotic stresses.Methodology. The work involved molecular genetic methods of DNA isolation, PCR analysis, restriction, and evaluation of amplification and restriction products in agarose or polyacrylamide gels. The material used included the diverse collections of Solanum lycopersicum and Capsicum annuum, as well as the specimens of closely related wild species.Results. The paper evaluates the effectiveness of 25 molecular markers presented in the literature associated with resistance to tomato and pepper diseases caused by fungal, bacterial, viral pathogens, as well as nematodes. Markers to the alleles of MYB transcription factor genes associated with the regulation of anthocyanin accumulation in tomato (SlMyb12, Anthocyanin1, Anthocyanin2, An-2-like and Atroviolacium) and pepper (Myb113-like1, Myb113-like2 and ETC3-2), recommended for the breeding process aimed at increasing resistance to stressful biotic and abiotic environmental factors, are presented.

Relevance. The modern direction of bean breeding is focused on increasing the protein content in seeds and green beans, as well as vitamins, folic acid, biologically active substances and antioxidants, improving organoleptic properties and reducing the content of anti-nutritional substances. When creating the initial material for breeding, the following traits are important: resistance to biotic and abiotic factors, stable high yield, technological effectiveness, bush type and upright form, high symbiotic activity. An effective approach to increasing the genetic diversity of the initial material is radiation mutagenesis.Purpose of research. To study the effect of γ-irradiation of seeds on germination, morphometric parameters and duration of phenophases of Russian bean varieties and to determine the optimal dose of γ-radiation for the radiation mutagenesis protocol.Materials and Methods. Objects of the study – 3 bean varieties bred by Omsk State Agrarian University. The seeds were γ-irradiated (source – 60Co) at doses of 50–200 Gy (dose rate 60 Gy/hour). The seeds were germinated under controlled conditions; germination energy and germination were assessed. The hypocotyl length, number and length of roots were measured in seedlings. The duration of development phases and productivity of plants were assessed. Statistical analysis was performed in R (ver. 4.3.3) and MS Office Excel 2019.Results. Hormesis effect was noted for 50 Gy γ-irradiation dose, which was manifested in higher values of germination energy and seed germination (variety Pamyati Ryzhkova), hypocotyl length (variety Marusya and Pamyati Ryzhkova) and in a decrease in the phenophases duration (variety Omskiy Rubin). Gamma irradiation at all applicable doses statistically significantly inhibited root development. Root length, as the most sensitive parameter to radiation, was chosen to calculate the dose causing a 50% growth reduction (RD50). For the Marusya variety, RD50 was 40 Gy, for the Pamyati Ryzhkova and Omsky Rubin varieties - 60 Gy.Conclusion. Variety specificity was established in the reaction to seed irradiation. Doses of 50 Gy or less (10-50 Gy) can be used to study the hormetic effects of γ-irradiation of bean seeds. Doses of 100 and 200 Gy turned out to be lethal. Starting doses of 40-60 Gy are recommended for the radiation mutagenesis protocols of Russian bean varieties.

Relevance. In recent years, we have seen an increase in the number of new bacterial fertilizers. New fertilizers must be effective, so it is important to select their qualitative and quantitative composition. It is equally important to study the effect of these bacteria on their number, dissemination and long-term residence in the soil, as well as their effects on plants.Aim of the Study. This work studies the effect of the method of obtaining a fertilizer containing Streptomyces coelicolor grown on the whey on the amount and duration of these bacteria in the soil and on the growth characteristics of white mustard (Sinapis alba L.) sown into the soil after a long time after watering with fertilizer.Methods. The whey was diluted and autoclaved, Streptomyces coelicolor were grown on this substrate. An inoculum for this biofertilizer was obtained in two ways. The first way: Streptomyces coelicolor were grown once on a Waksman`s media. The second way: the inoculum was sequentially grown on the whey, gradually increasing the volume. Bacteria in fertilizer were cultivated without mixing or by mixing in the temperature-controlled shaker. We studied the effect of biofertilizer on soil in containers in the laboratory. The amount of Streptomyces coelicolor in the soil was determined 0.5, 1.5, 2 and 4 months after watering by fertilizer. Seeds of white mustard were sown two months after watering with fertilizer. We studied the effect of fertilizer on growth characteristics of white mustard.Results. The fertilizer obtained by sequentially cultivating the inoculum and growing streptomyces without mixing contained ten times more streptomyces than fertilizers obtained by another method. This biofertilizer also effectively increased the number of streptomyces in the soil. Streptomyces from fertilizer have been preserved in the soil for a long time. The effect of biofertilizers obtaining without mixing on growth characteristics of white mustard was the most effectively.Conclusion. The fertilizer obtained by sequentially cultivating the inoculum and growing streptomyces without mixing contributes to a more increase of streptomyces number in the soil and is more effective in growing white mustard then fertilizers obtained by other methods. Our biofertilizer is effective in growing crops sown in the soil for a long time after watering with fertilizer. The fertilizer can be used in indoor crop production and greenhouse farms.

Relevance and research material. In 2023, it was 100 years since the beginning of the collection, study and preservation of the world doublet collection of potatoes (UNU, registration USU_505851) at the Polar Experimental Station of the VIR branch. This is one of the oldest and unique potato collections, the preservation of which is carried out in the field. The first potato samples began to enter the collection in 1923. Now the potato doublet collection has 3200 samples. It includes breeding varieties, hybrids, cultivated South American potato species Solanum andigenum Juz. et Buk, Solanum chilotanum Hawkes.Results. The collection is a unique genetic material that is of high importance in solving issues of improving the efficiency of agriculture in the country. As part of the field collection of potatoes, the source material for dangerous quarantine objects is quite widely presented: potato cancer (Synchytrium endobioticum (Schilb.) Persiva) and globoderosis (Globodera rostochiensis Woll.). There are donors of late blight resistance (Phytophthora infestans (Mont.) de Bary.). There is a source material in the collection that has economically valuable characteristics: precocity, frost resistance, yield, marketability. Varieties with a high amount of phenolic compounds in the tuber pulp are also included in the field doublet collection. Such varieties are suitable for dietary nutrition and can be used in the prevention of a number of diseases.Conclusion. The collection of the collection is of great importance for applied research and for ensuring food security of the region and the country as a whole.