Relevance. Currently, downy mildew of cucumber (peronosporosis) is the most harmful disease on this crop in the open ground, has an epiphytotic character and causes significant damage to the crop of greens. Material and methods. The research was carried out on selection and collection material of the laboratory of selection and seed production of pumpkin crops in the open and protected ground of the Moscow region. At least 300 collection and selection samples of cucumber were sown in the open and protected ground (Moscow region) every year, for phytopathological evaluation. Their defeat by downy mildew was taken into account on a 5-point scale. Results. Among the varieties of FSBSI FSVC selection, were less affected by this disease: Edinstvo, Electron 2, Vodoley, Vodopad, F1 Debut, F1 Krepish, F1 Brunette, F1 Frant, F1 Krasotka and F1 VNIISSOK 1. The most resistant to peronosporosis were Japanese varieties – Sadao rishu, Jibai, Higan Fushinari, Tropical slicer and others. Some Polish hybrids – Aladyn (SKW 190), Heron (SKW 290) and Parys (SKW 390), also had increased resistance to downy mildew. It should be noted that the varieties Jerelo and Geim from Ukraine; Dutch hybrids – F1 Sequenza, F1 Bejo 1612, F1 Pontia, 85/2292, F1 Donia mix; from the United States – F1 Calypso. In the selection for resistance to downy mildew you can to use varieties created in the Far East, the Crimean experimental breeding station. As a result of the annual assessment of parent forms on a natural infectious background, samples with increased resistance to downy mildew were selected.

Relevance. One of the conditions for creating a modern high-tech hybrid of sweet pepper is the presence of resistance to the Pepper mild mottle virus (PMMoV). This virus belongs to the genus Tobamovirus. This virus can spread through seeds, causing enormous damage to the sweet pepper crop. The main method of controlling of virus is the cultivation of F1 hybrids of pepper with genetic resistance. To date, the L4 gene is able to confer resistance to all known strains of this virus. However, there is still no reliable marker system that could be integrated into the MAS. Methods. Based on data from the NCBI, we generated a molecular diagnostic system based on hybridization probes. Validation was performed on seven pepper accessions from the world's germplasm banks. After validation, the new marker was successfully tested on 2540 plants of F2 and F3 generation. Results. Using the experimental marker system Fret4, we tested 7 reference samples of pepper germplasm with full correspondence of the melt peaks to the declared alleles of the L gene (L0/L1/L3/L4). Then, using a marker system, MAS was carried out on 10 populations of an number of 10 thousand plants to identify the L4 allele. As a result, we were able to create a highly accurate and cost-effective marker system for the most important pepper resistance gene. This marker system based on hybridization probes is easily integrated into the MAS, allowing fast and reliable determination of the L4 allele state in sweet pepper breeding to Tobamovirus.

Relevance and methods. Pumpkin fruits and seeds are valuable raw materials for the food and pharmaceutical industries. Of particular value are pumpkin seeds, from which oil and protein products are obtained. The purpose of our research is to identify the best breeding samples of pumpkin in terms of seed yield and pumpkin oil and to study their biochemical composition. The evaluation of 12 samples of pumpkin was carried out according to the main economic and biological characteristics. Results. According to the yield of seeds and the yield of pumpkin oil, the following samples were distinguished: Delta, Golosemyanno-kustovaya, Line 2-3, Line 2-5. The biochemical composition of seed samples with high seed yields was studied in terms of the content of proteins, fats, carbohydrates, amino acids, fatty acids, vitamins and minerals. A biochemical analysis of pumpkin seed oil for fatty acids, sterols and minerals was carried out. Seeds of hard-barked pumpkin of Belarusian selection are sources of high protein content (34-35%) with a wide range of essential amino acids, fats (43-45.8%), unsaturated and saturated fatty acids, as well as carbohydrates (9.6-11.9%) , a number of vitamins, macro- and microelements.

Relevance. A study of the seasonal (phenological) phenomena and natural connections between them on the background of the relevant environmental conditions is of great scientific and practical interest. Knowledge of the dynamics of the seasonal development of woody plants helps in the selection of species and their assessment from an aesthetic and sanitary points of view, as well as in the development and implementation of measures to increase the sustainability of urban green spaces. Materials and methods. The purpose of these studies is to create a database of the dynamics of seasonal development of North American woody plants based on the results of many years of phenological monitoring (2003-2017). The 20 species and forms of North American woody introducers e of the VNIISPK arboretum genetic collection were the objects. Results. It was revealed that the growing season of woody North American plants corresponds to the climatic conditions of the forest-steppe zone of central Russia. The species with the earliest beginning of the growing season (the third decade of March) were distinguished. There were Mahonia pinnata, M. aquifolia, Betula lenta and B. lutea. On the basis of phenological calendars, phenological spectrums have been constructed. These consist of three lines (the development of leaves, shoots, flowers and fruits) with the corresponding color symbols. It has been revealed that phenospectrums vary depending on the conditions of the year. As a result, the database of 20 species and forms of North American woody plants was formed in the form of phenological spectrums against the background of registration of weather conditions in the forest-steppe zone of Russia. The database includes three options for the possible dynamics of the seasonal development of introduced North American plants. The created database allows observing, comparing, evaluating and forecasting changes in the seasonal rhythm of the studied species of introduced North American plants.

Relevance. Leek (Allium porrum L.) has been known as a cultivated plant since ancient times. It plays an important role in human nutrition. To increase the interest of the population, increase demand and consumption, as well as widespread and popularize this culture, it is urgent to create new promising varieties of leeks that meet modern requirements and have valuable economically useful traits. The creation of new highly productive varieties is associated with the search for sources of valuable biological and economic traits: productivity, early maturity, yield. The aim of the research was to study collection varieties of leeks, to identify the sources of the necessary valuable traits for their further use in breeding work. Materials and methods. The initial material was 73 samples of leeks of the European subspecies of various ecological and geographical origin from the collection of VIR. The studies were carried out at the collection site of the Krymsk EBS, VIR Branch (Krasnodar Territory, the city of Krymsk). Results. As a result of the study of phenological, biological, morphometric and economic characteristics, the foliage of the plant, the size of its and the false stem of the "leg", productivity and yield were determined. Formed groups of samples by ripeness and use. Comparative assessment of collection samples made it possible to identify the sources of productivity: the weight of the plant and the stem, its diameter and height, the yield of plants and the yield of marketable products. The isolated sources of valuable traits are recommended as a starting material for the selection of leeks.

Relevance. To create heterotic cucumber hybrids, it is important to have a high general and specific combining ability of the initial material, which makes it possible to select valuable genotypes at an early stage of selection. Material and methods. The research was carried out in 2018-2020. at the Research Institute of Vegetable, Melon Crops and Potatoes, located in the Tashkent region of Uzbekistan (SRIVMC&P). Studied 6 accessions of cucumber. As a result of diallelic crosses, 36 hybrid combinations were obtained (p2). Hybridological analysis was carried out according to the first Griffing's method, including forward and backcrossing and the use of parental forms (p2). To determine the combining ability, conventional methodologies were used (1,15). Genetic-statistical analyzes were carried out using the MS Excel application package. Results. Studies have established that according to the traits "the number of days from seed germination to the opening of female flowers" and "the number of days until the technical ripeness of fruits" in all studied cucumber accessions, the ratio (σ 2ĝi<σ 2si) is observed, where the dominant role in the inheritance of this trait also belongs to genes with dominant and epistatic effects. The trait “number of fruits per plant” is controlled by dominant and epistatic gene effects (σ 2ĝi<σ 2si) in almost all cucumber accessions, and in the accession A-6 - by additive gene effects (σ 2ĝi <σ 2si). The phenomenon (σ 2ĝi <σ 2si) was noted for the trait "average fruit weight", where the expression of the trait is controlled by the dominant and epistatic effects of genes (σ 2ĝi <σ 2si) in three studied cucumber accessions (C-25/1, A-6 and A-9), and in the other three accessions, additive gene effects (σ 2ĝi <σ 2si) are more important in inheritance. The trait "productivity of one plant" is controlled by the dominant and epistatic effects of genes (σ 2ĝi <σ 2si) in the three studied cucumber accessions, and in the other three accessions (C-25/1, A-6 and A-9), genes play a special role for the expression of the trait with additive effects. Promising hybrid combinations with the best performance for their use as a initial material for breeding have been revealed.

Relevance. The use of certain single or mixed cultures of lactic acid microorganisms and the mandatory control of the fermentation process of white cabbage are of great importance to ensure that the product is of stable quality without the need for any chemical preservatives or harsh processing conditions. Carbohydrates contained in raw materials play an important role in this process, since carbohydrates are the main source of maintaining the viability of lactic acid microorganisms. By adjusting the carbohydrate component of raw materials at different stages of fermentation, it is possible to maintain a high titer of microorganisms, while obtaining not only a high-quality product, but also giving it, along with prebiotic (a source of fiber) and probiotic properties. Materials and methods. The purpose of this research work was to ensure the direction of the biotechnological process in the direction of stabilization of the concentration of functional microflora (starting systems of lactic acid microorganisms), under the influence of introduced carbohydrate nutrients. In this work, we studied two fermentation systems of microorganisms that are fundamental microorganisms in the fermentation of cabbage, namely, systems consisting of a pre-fermentation culture of Leuconostoc mesenteroides and one of the cultures of lactobacilli: Lactobacillus plantarum or Lactobacillus brevis. The study used the usual microbiological method for determining the number of microorganisms by seeding in an agarized culture medium, as well as processing experimental data. Results. As a result, we found that the introduction of a carbohydrate Supplement allows us to stabilize the dynamics of changes in the concentration of the studied starting systems at the same initial level throughout the main stage of fermentation.

Relevance and methods. For the Non-chernozem zone, the main factor for the active development of late blight is the low air temperature and its sharp fluctuations during the day, contributing to the formation of increased air humidity and drip-liquid moisture on the plants. In the Moscow region, the causative agent of late blight is manifested almost annually. Populations of Phytophthora infestans are represented by the To and T1 races. Epiphytotic development was observed periodically (1977-1979, 1982, 1986, 1996-1999, 2000, 2001, 2003-2004, 2008-2009, 2013, 2014, 2015, 2016, 2017, 2019) and was provided by the virulent T1 race. Observations showed that epiphytotic situations arose in those years when the minimum air temperature was below long-term average values, and relative humidity and precipitation exceeded them. With a deviation from the norm in the direction of increasing temperature, decreasing rainfall and relatively low humidity, years were observed with a depressive (1992, 1994) or moderate development of the disease (1980, 1981, 1983, 1985, 1987-1991, 2002, 2005-2007, 2010-2012, 2018). Results. As a result of breeding work, a Grot tomato-tolerant tomato variety was obtained, on the basis of which varieties with high resistance Grand, Dubok, Gnom, Chelnok, Patris, Geya, Zolushka, Perst, Severyanka, Blagodatny were obtained. In the general collection of VIR as a source resistance to leaf spot pathogens were registered: Geya (v.k. 14839), Slavyanka (v.k. 14840), Patrice (v.k. 14841), Rossiyanka (v.k. 14842), Krepysh (v.k. 14843), Sibiryachka (v.k. 14444) and line 1079-94 (v.k. 14845) donors, in addition to their high resistance to late blight, have excellent economic characteristics.

Relevance. In the conditions of the dry-steppe zone of lowland Dagestan, the beneficial effect of drip irrigation in combination with dump cultivation on the yield and quality of sweet pepper fruits from Moldova proved. Results. It experimentally established that maintaining moisture in the active 0.5 m soil layer during the growing season within 80- 100% of LMC against the background of dump processing to a depth of 0.23-0.25 m led to an increase in yield and biochemical composition of sweet pepper fruits. Differences in the influence of dump and small (0.10-0.12 m) tillage on agrophysical and phytosanitary indicators of fertility of meadow medium loamy soil were revealed. The data showing the inappropriateness of using small-scale cultivation under conditions of irrigated vegetable growing, which leads to a deterioration in the agrophysical indicators of fertility: increase in soil density by 0.05-0.08 t/m3, decrease in the number of water-resistant units by 7,0%, water permeability reduction by 22.0% and water resistance coefficient by 12.9%, 2.1 times increase in planting weed and 212.6% potential soil weed. Of the three studied thresholds of soil moisture (70, 80 and 90% LMC), it was established that the best conditions for plant growth and development, optimization of their photosynthetic activity are created at a humidity threshold of 80% LMC, at which the most efficient use of irrigation water is noted. Drip irrigation with maintaining the pre-irrigation threshold for soil moisture not lower than 80% of against the background of dump processing leads to an increase in the number of fruits on 1 plant, an increase in the mass of 1 fruit, which contributed to an increase in yield to 62 t/ha.

Relevance. One of the most important directions in the breeding and variety study of fruits, in particular domestic plum European, is the breeding of cultivars with high commercial and consumer qualities of fruits. In this regard, the assessment of some commercial and consumer qualities of fruits in plum cultivars of the RRIFCB gene pool was of great practical and scientific interest. Material and methods. As objects of research, we used 8 plum cultivars of the RRIFCB gene pool and a control cultivar of the RRIFCB breeding Bolkhovchanka. The studies were carried out on the basis of the laboratory of breeding and variety study of stone fruit crops of RRIFCB in 2015-2019. Determination of color, shape, average weight, taste, size of fruit, size and shape of the stone, density of pulp, separation and length of the stalk, color of the juice were carried out in accordance with the "Program and methodology for the variety study of stone fruit crops" and "Pomology". Results. Most of the studied plum cultivars from the gene pool of the Russian Research Institute for Fruit Crops Breeding have valuable commercial and consumer qualities of fruits, which will allow them to be used in further breeding for this trait. Cultivars Californiyskaya krupnaya, Zarechnaya rannyaya, Volgogradskaya can be recommended for further use in breeding as sources of high fruit mass. Cultivars Californiyskaya krupnaya and Bolkhovchanka can be recommended for further use in breeding as sources of high pulp content in fruits and fruit sizes. On the basis of the tasting assessment of the fresh fruits, the fruits of the cultivar Volgogradskaya stood out positively.