Elena Valerievna Ambros

Astragalus glycyphyllos (Fabaceae) is known to be a source of flavones, flavonols, and isoflavones, and its in vitro culture may promote the efficiency and sustainability of obtaining pharmacologically valuable fractions. The aim of this study was to develop an effective plantlet regeneration protocol for A. glycyphyllos, providing the accumulation of phenolic compounds and antioxidants in cultured tissues. The results show a maximum seed germination rate (67.8%) after scarification (mechanical with sandpaper followed by treatment with 50% sulfuric acid) and subsequent sterilization with 1.1% sodium hypochlorite solution. The maximum regeneration rate (95%) was achieved on Murashige and Skoog medium supplemented with 0.5 mg·L⁻¹ thidiazuron. A thidiazuron concentration of 0.05 mg·L⁻¹, combined with a twofold increase in iron chelate content, induced the maximum yield of total flavonoids (8.74 mg·g⁻¹ DW), and significant levels of total phenolics (4.15 mg·g⁻¹) and antioxidants (1.83 mg AAE·g⁻¹) in the microshoot tissues. HPLC analysis showed kaempferol glycosides (1.51 mg·g⁻¹) and acylated kaempferol glycosides (2.76 mg·g⁻¹) as major components. Formononetin in a modest amount (0.09 mg·g⁻¹) was detected in hydrolyzed extracts. The phenolic profiles of the microshoots and native plants coincided in hydroxycinnamic acid composition; meanwhile, quercetin glycosides were present only in in situ plants, and formononetin was found only in the plantlets. The results confirm the prospects of biotechnological methods for the industrial production of standardized medicinal raw materials.

The relevance of the study stems from the need to optimize the technology of clonal micropropagation Fragaria × ananassa to obtain high-quality planting material with high productivity and preservation of varietal identity. The study investigated the influence of cytokinins (6-benzylaminopurine and thidiazuron) on the generative productivity of the plantlets of the cvs. Solnechnaya Polyanka and Alfa during two years of in vivo conditions. Clonal micropropagation contributed to the accelerated entry of the plantlets into the generative phase of development compared to plants propagated using the traditional method, ensuring fruiting already in the first year of cultivation. The impact of growth regulators on the components of generative productivity in the studied cultivars varied: thidiazuron increased the number of fruits in the cv. Solnechnaya Polyanka, and 6-benzylaminopurine increased it in the cv. Alpha. The effect of growth regulators decreased by the second year, and their effect on fruit weight also depended on genotype. In the cv. Solnechnaya Polyanka, 6-benzylaminopurine increased the weight of fruits of the 1st and 2nd order, while in the cv. Alpha, thidiazuron, increasing the weight of fruits, reduced their total number. The development of effective protocols for clonal micropropagation of garden strawberry requires an individualized approach to each cultivar, taking into account the genotypic characteristics to achieve maximum productivity and maintain varietal identity.

The article discusses the methodological aspects of making classes with schoolchildren who attend a biology elective course and study the growth and development of ornamental plants in a school botanical garden and a biotechnology laboratory. The article demonstrates the possibility of students mastering the methods used in scientific research, as well as making statistical analysis of data obtained from observations and experiments. The cycle of school – bachelor’s degree – master’s degree – postgraduate studies is being worked out on the example of a specific interaction between academic science, higher education, and school education. The biometric measurements of ornamental plants and subsequent statistical data processing, the variety assessment of garden roses, phlox, and daylilies, as well as the determination of the stages of organogenesis of renewal buds in ornamental perennials at the end of the growing season, have aroused the greatest interest among students in grades 5–8. The projects of flower expositions and the selection of assortment for the educational garden were carried out by the staff of the Central Siberian Botanical Garden of Siberian Branch of the Russian Academy of Sciences and the students of the Siberian State University Engineering and Biotechnology, with the aim of achieving a high decorative effect in the flower beds at the main entrance during the main celebrations associated with the end of school (peonies, irises) and the beginning of the school year (garden roses, Korean chrysanthemums). Recommendations are given for the microclonal propagation of Korean chrysanthemum varieties based on the biotechnology module available at the school.

One of the problems of insufficient cultivation of garden strawberries in the Novosibirsk region is the lack of industrial production of high-quality planting material, on which the crop yield directly depends. The technology of clonal micropropagation can help to solve the problem of obtaining genetically identical healthy planting material of high quality. The efficiency of clonal micropropagation largely depends on the optimization of the cultivation stages. Adaptive responses of garden strawberry regenerants (‘Solnechnaya Polyanka’, ‘Alpha’) during rooting and ex vitro acclimation under the influence of an environmentally friendly silicon-containing mechanocomposite made from renewable plant materials were studied. To stimulate rhizogenesis in microshoots the following treatments were used: watering with an aqueous solution of Murashige-Skoog nutrient medium containing ¼ concentration of standard medium components; pulse treatment with an aqueous solution of 30 mg/l indoleacetic acid (for 4 hours) followed by watering with a solution of ¼ Murashige-Skoog; a single watering with a solution of ¼ Murashige-Skoog with the addition of 0.3, 1.0, 3.0 g/l of mechanocomposite; dry dipping the basal part of the microshoots with a mechanocomposite followed by watering with a solution of ¼ Murashige-Skoog. It was found, that dry dipping the basal part of the microshoots with a mechanocomposite is the most effective treatment method of regenerants in ex vitro conditions. This treatment significantly increased the frequency of rhizogenesis (up to 95% versus 25-45% in the control), stimulated the development of the root system (the length of the roots increased relative to the control by 2.5-4.3 times, the number of roots per plant by 1.2-2.0 times, the dry weight of the roots by 3.0 times for the cv. ‘Alpha’) and the above-ground system of plants (the area of the leaf blade increased by 1.2-2.0 times, the dry weight of the shoots by 2.6-3.7 times), increased the content of the main photosynthetic pigments in the leaves of the regenerants (the content of chlorophyll a + b increased by 1.2 times, carotenoids by 1.2-1.4 times). Under the influence of the mechanocomposite, the leaves of the regenerants acquired signs of a xeromorphic organization. An increase in the density of stomata on the abaxial side of the leaf in the cv. ‘Alpha’ (by 1.4 times), intensive accumulation of epicuticular waxes on the lower epidermis of the leaf blades of the regenerants of two cultivars was noted. It was determined that silicon accumulates in the aboveground part of the garden strawberry regenerants. The minimum silicon content was in the control (2020 μg/g), under the influence of the mechanocomposite, the silicon content increased (up to 3500 μg/g with watering and 3200 μg/g with dusting with the mechanocomposite). The developed technology allows to eliminate the in vitro rooting stage and reduce the overall clonal micropropagation cycle by 4 weeks, ensuring high quality of garden strawberry planting material.

Due to the protective role played by silicon in plants against unfavorable environmental conditions, siliconcontaining preparations are of considerable interest as biostimulants. In this work, a mechanical composite of rice husk and green tea containing soluble silica chelate complexes was used as the source of silicon. The study aims to examine the effect of silicon chelates on the growth and physiological parameters and the chemical composition of Fragaria × ananassa plants (Solnechnaya Polyanka variety) under greenhouse conditions. The plants were watered using water without a mechanical composite (control) or an aqueous solution containing 0.3 g/L of mechanical composite twice per period. Sampling was carried out one week after the last treatment. In order to determine the concentration of chemical elements (Si, P, S, Cl, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr, and Mo) in the roots and shoots of garden strawberry, it was proposed to use synchrotron X-ray fluorescence analysis. The use of the mechanical composite was shown to increase the amount of chlorophyll a, chlorophylls a and b, and carotenoids; decrease the amount of hydrogen peroxide; and increase the activity of the main antioxidant enzymes (superoxide dismutase, catalase, and peroxidase). It was determined that under the effect of the preparation, silicon accumulates primarily in shoots, affecting the accumulation of micro- and macroelements in the shoots and roots of plants. The obtained results substantiate the use of silicon-containing “green chemistry” as a means of controlling the growth and development of garden strawberry plants under in vivo conditions.

The purpose was to assess the effects of a biostimulant based on silicon chelates in terms of alleviation of the impact of in vivo conditions on strawberry (Fragaria × ananassa cv. ‘Solnechnaya polyanka’) in-vitro-derived plants. As a source of silicon chelates, a mechanocomposite (MC) obtained through mechanochemical processing of rice husks and green tea was used. Root treatment of plants with 0.3 g L⁻¹ of MC dissolved in tap water was performed at 2 weeks after planting. Control plants were watered with tap water. The greatest shoot height, number of roots per plant, root length, number of stolons per plant, daughter ramets per stolon, relative water content, cuticle thickness, and root and shoot biomasses were achieved with the MC supplementation. The improved parameters were associated with a higher silicon content of roots and shoots of the MC-treated plants. Leaf concentrations of hydrogen peroxide and abscisic acid were reduced by the MC. This effect was accompanied by enhanced activity of superoxide dismutase and catalase. The phenolic profile showed upregulation of p-hydroxybenzoic acid, vanillic acid, gallic acid, syringic acid, and ellagic acid derivative 2, while kaempferol rutinoside and catechins were downregulated. Thus, silicon chelates improve growth and trigger the physiological processes that enhance free-radical-scavenging activity in strawberry plants in vivo.

The positive effect of silicon on plants is thought to be mediated by a modification of phenolic metabolism. The purpose of the study was to evaluate the effect of a silicon-based mechanocomposite (MC) on alterations of the phenolic profile of strawberry plants in the course of development under in vitro, ex vitro, and in vivo conditions. Aqueous ethanol extracts of aboveground parts of in vitro–derived plants (Fragaria × ananassa cv. ‘Solnechnaya polyanka’) were subjected to HPLC. Nineteen individual phenolic compounds (hydroxybenzoic and hydroxycinnamic acids, catechins, ellagic acid derivatives, and flavonol glycosides) were quantified. The results revealed phenolic profiles specific to each studied stage and significant transformations of the profiles by the MC. It induced strong upregulation of hydroxycinnamic acid during in vitro rooting and of catechins and hydroxybenzoic acids during ex vitro acclimation. At ex vitro and in vivo stages, the emergence of quercetin glycosides and ellagitannins was registered, and the MC elevated their levels during ex vitro acclimation and field growth. Principal component analysis confirmed the significant effect of the MC on the phenolic profile at all stages, and this effect was the strongest during ex vitro acclimation. The results are consistent with previous reports on the modification of phenolic profiles of plants by silicon-derived biostimulants.