The development of new grape varieties with improved quality and resistance against environmental factors using biotechnological methods is a pressing task in the context of import substitution policy implementation. Due to the high heterogeneity of grape varieties, techniques for regenerating plants from embryogenic callus by somatic embryogenesis have been developed only for a small number of genotypes. This work presents a versatile approach to the development of globular, heart, and torpedo embryos in various grape genotypes. Experiments were carried out using cultures of colchicine embryogenic cell suspensions and somatic globular embryos of the E-342 hybrid form in liquid media. The developed methodology allows the protocols of embryogenesis and polyploidy induction to be effectively improved. The versatility of the presented methodology for polyploidy induction and somatic embryogenesis in grape plants is ensured by a fourfold reduction in the concentration of inorganic nitrogen and vitamins in the NN and PG media and the addition of organic nitrogen and other biological active substances at the stages of embryogenic callus development, colchicination, and development of somatic embryoids in liquid media. The methods of indirect ploidy determination by the properties of the grape leaf epidermis were studied and implemented. Nine promising somaclones were preliminary selected based on a set of four features. It was established that full-fledged transgenic grape plants can only be obtained by the method of transformation, which involves the production of embryogenic callus from a leaf explant, its subsequent passage into a liquid culture to obtain a liquid embryo culture, and the transformation of this culture. In total, 300 leaf explants of the Libya variety and 1 100 globular embryos of the Podarok Magaracha variety were transformed. As a result, six callus kanamycin-resistant lines of the Libya variety and six lines of transgenic plants of the Podarok Magaracha variety were selected. Following genotyping based on nine nuclear microsatellite loci, seven unknown forms with a seedless phenotype were identified. Among the population of hybrid seedlings, hybrids having alleles associated with seedlessness were revealed using the VMC7f2 and p3_VvAGL11 MAS markers.

Walnut is one of the most economically significant nut crops. Evaluation of the genetic structure of the domestic walnut gene plasma using modern molecular genetic approaches is a relevant research task. The walnut samples collected by Tsitsin Main Moscow Botanical Garden of Academy of Sciences (MBG RAS) are of particular importance for breeding practice aimed at increasing winter freezing tolerance of plants. The seed material for this collection was introduced from different regions of the former Soviet Union, including Tajikistan, Kyrgyzstan, Ukraine, Belarus, as well as regions of Russia. The MBG RAS collection presents interest as a breeding material for mobilizing the genetic resources and replenishing the gene pool of the South of Russia with new, economically valuable walnut varieties. This work aims to analyze the genetic diversity of a J. regia genotype sample, which includes the most valuable forms from the MBG RAS collection, in order to establish their genetic relationships with samples representing the walnut gene pool of the South of Russia. The genetic analysis of the studied walnut species and varieties was carried out using eight SSR markers: WGA001, WGA376, WGA069, WGA276, WGA009, WGA202, WGA089, and WGA054. The polymorphism of microsatellite DNA markers established during genotyping indicated a high heterogeneity between the MBG RAS walnut sample and genetic resources in other regions. An analysis of genetic relationships using UPGMA and PCoA clustering methods revealed the genetic isolation of most samples in the MBG RAS collection from walnut varieties in the South of Russia. The most genetically distant samples in the MBG RAS collection were found to be 199, 196, 236, 256, 106, and 134. Therefore, these samples should be introduced in the gene pool of North-Caucasus Federal Scientific Center of Horticulture, Viticulture, and Wine-making and Nikitsky Botanical Garden with the purpose of increasing the heterogeneity of their gene pools.

In 2021–2022, experiments were conducted at the Laboratory of Fruit Crop Resistance Physiology, All-Russia Institute for Fruit Crops Breeding (VNIISPK), to investigate the action of the “White Pearl Antifreeze” (Belyi Zhemchug Antifriz) phytomodulator and the “White Pearl Drip Ca + Mg” (Belyi Zhemchug Drip Ca+Mg) phytocorrector produced by the AgroPlus Group of Companies, LLC. Experimental and control plots were characterized by dark-gray forest soils with a humus content of 3-4 % and a humus horizon thickness of 30–35 cm. Apple trees cv. Sinap Orlovsky (VNIISPK) grafted on semi-dwarf rootstock 54-118 were planted in 2013 according to a 6 x 3 m scheme. Natural grassing was used in row spacings; herbicides were applied around the seedlings. The experimental design included: 1) control (water treatment) and 2) foliar treatment with a 1 % solution of “White Pearl Antifreeze” + a 1 % solution of “White Pearl Drip Ca+Mg”. The experiment was conducted in three replications with five observed trees in each. Our aim was to assess the effect of the mentioned preparations on the spring frost tolerance, yield, and quality of apple fruit under the weather conditions of 2021. Foliar treatments with the studied preparations reduced the frost damage to Sinap Orlovsky apple buds by 6.3 % at -3.5 °С and by 10.4 % at -4 °С. The conducted summer foliar treatments with the organomineral mixture under study intensified the growth and ripening of apple fruit. The improved protein-carbohydrate metabolism, water regime, photosynthetic activity, and donor-acceptor leaf–fruit relations increased the fruit weight by 10 g and the yield by 1.8 times. The conclusion is made that the B-PLUS “White Pearl Antifreeze” preparation exhibits a complex effect in terms of increasing plant tolerance to low-temperature spring damage, thus improving the yield and quality of apple crops.

Variations in the phenolic content (total polyphenols, theaflavins, and thearubigins) of unconventional brands of ready-made tea (white, red, GABA) depending on different processing methods are discussed. Research in this direction has been carried out at the Subtropical Scientific Center of the Russian Academy of Sciences (FRC SSC RAS, Sochi) since 2017. Krasnodar tea was shown to contain polyphenols, theaflavins, and thearubigins in the amount of 18.47, 0.14, and 0.79 mg/g, respectively. Non-fermented and semi-fermented teas contain the highest amounts of polyphenols: white (16.63 mg/g), green (16.51 mg/g), and light GABA (16.47 mg/g). When processing light GABA tea, no change in the content of polyphenols occurs; however, the number of flavonoid pigments reduces significantly. Thus, the content of theaflavins (0.02 mg/g) remains at the level of white tea (0.03 mg/g), while that of thearubigins decreases significantly (0.26 mg/g as compared to 0.43–0.46 mg/g in white and green tea, respectively). The content of polyphenols in fermented teas (black, red) is significantly lower than that in raw material and non-fermented teas (НСР05 = 1.18). At the same time, black tea contains theaflavins (0.04 mg/g) and thearubigins (0.95 mg/g) in higher levels. To a certain extent, red tea is inferior to black tea in terms of polyphenols, although red tea is comparable to white and green teas in terms of flavonoids (0.04 mg/g of theaflavins and 0.39 mg/g of thearubigins). With respect to phenolic components, dark GABA tea approaches nonfermented and semi-fermented teas, which increases its nutritional value. The obtained data can be used when developing approaches to regulating the quality characteristics of ready-made tea produced under humid subtropical conditions in Russia, ensuring the preservation and improvement of product quality.

Current approaches to land use and agricultural production are increasingly aimed at achieving high productivity through the use of crop rotation, siderites, integrated plant protection, minimized soil cultivation, microbiological fertilizers, and biological preparations. Modern microbiological preparations enhance the uptake of nitrogen and ash elements by plants, improving the rhizosphere of plants and the quality of strawberry fruit. Aim. To establish the effect of Extrasol applied using drip irrigation and various forms of mineral nitrogen fertilizers on the chemical composition of leaves and fruit of garden strawberry.Materials and methods. Garden strawberry plants of the Rusich and Troitskaya cultivars were treated with Extrasol and mineral fertilizers. Experiments were carried out in 2017–2020 at open-ground plots of the Federal Horticultural Center for Breeding, Agrotechnology and Nursery (Moscow Oblast). The experimental plots were characterized by soddy podzolic soils of medium-loam granulometric composition. Plant samples were analyzed using conventional methods. The experimental scheme consisted in the application of various nitrogen fertilizers (ammonium nitrate, urea, and ammonium sulfate) either in combination (2 mL/L of the working solution) or without Extrasol. Conclusions. In strawberry cv. Rusich, the use of ammonium nitrate increased the calcium content in plant leaves and decreased its content in fruit, which negatively affected the crop quality. Mineral fertilizers applied in combination with Extrasol increased the nitrogen content in leaves and fruit. The combined use of the amide form of nitrogen (urea) and Extrasol adversely affected the level of nitrates in cv. Troitskaya fruit. The use of fertigation and Extrasol reduced the amount of soluble dry substances in strawberry fruit.

Advances in grapevine biotechnology are associated with manipulation of vegetative and generative plant organs, effective use of the soil and climate potential of agricultural lands, and biological features of grape genotypes. Grapevine biotechnology allows grape productivity to be increased without additional investments. In this work, we studied table grapes of the Libya variety grafted onto a Chasselas.×V. Berlandieri 41B rootstock to determine variations in grape productivity depending on the different load of vines with shoots and bunches. The research was carried out in the Central Agroecological Zone of Viticulture (fourth subzone) of the Krasnodar Krai, in vineyards with drip irrigation and covered viticulture. The vines were planted according to a 3.8×2.0 m scheme with a density of 1316 plants per hectare. The vines were supported with a high-trunk two-arm horizontal cordon system. The average annual air temperature at the experimental site equaled +12.5... 13.0 °С; the sum of active temperatures was 3 900-4 100 °С; the maximum temperature during vegetation reached +40 °С; the minimum temperature of -30 °С was recorded in winters during dormancy. The annual precipitation level comprised 700-800 mm. The soils were low-humus, leached powerful chernozems. In terms of productivity, grapes of the Livia variety respond effectively to canopy management techniques. In this work, changes in bunch weight and grape yield were monitored depending on the load of vines with shoots and bunches. Under the studied agroecological conditions, the largest bunch mass of 870 g was achieved at the lowest load of 20 shoots and 22 bunches per vine. The maximum grape yield of 36.3 t/ha was observed with an average load of 26 shoots per vine and the largest load of 37 bunches per vine. The dependence of yield on shoot number was rather low, r = 0.08; on bunch number was medium, r = 0.53; on bunch mass was high, r = 0.75. The largest share of marketable grape yield of 98% was achieved at the load of 20 shoots and 22 bunches per vine.