Clonal Micropropagation Research Articles

In vitro clonal micropropagation of selected Malus niedzwetzkyana Dieck forms demonstrating high resilience when introduced into urban environments

Background. Currently, the use of an interdisciplinary approach based on a combination of traditional introduction methods and clonal micropropagation techniques makes it possible to solve one of the key problems of introduction – the establishment of bioresource collections consisting of selected plant accessions with valuable agronomic traits and resistance to unfavorable urban environments. Materials and methods. A plant introduction study resulted in identifying seven specimens of Malus niedzwetzkyana Dieck with resilience to urban environments, high rate of crown development, and longevity. They served as source material for the development of a clonal propagation protocol and in vitro preservation of selected genotypes of this species. Results. It was shown for M. niedzwetzkyana that the most favorable time for taking its plant material for introduction into in vitro culture is the beginning of the active growth of vegetative shoots after flowering. The most optimal sterilization technique for such plant material was a stepwise regime using alcohol, sodium hypochlorite, and silver nitrate: it provided from 50 to 70% of sterile explants and the maximum percentage of meristem proliferation. Combining 0.8 mg/L of benzylaminopurine (BAP) with 0.14 mg/L of indole-3-butyric acid (IBA) at the stage of microclonal propagation ensured a significant increase of the reproduction coefficient (on average up to 5.3 ± 0.7) and an improvement in morphometric parameters of microshoots; the maximum frequency of shoot proliferation was 100%. The yield of shoots adapted to ex vitro conditions was 90%. Conclusion. The developed clonal micropropagation protocol made it possible to introduce selected M. niedzwetzkyana forms into in vitro culture and reproduce them in order to set up a resource base for further fundamental and applied research into the system of the genus Malus Mill.

Enhancing Clonal Micropropagation of Zarya Alatau Apple

The purpose of this study was to improve the protocol of clonal micropropagation for effective mass production of the Zarya Alatau apple cultivar through the use of axillary buds. In Kazakhstan’s challenging climate, the Zarya Alatau apple thrives because of its unique traits, including fruit preservation until May, cold hardiness, and resistance to scab and powdery mildew. Micropropagation is essential for healthy mother tree establishment, and this research focused on key factors for successful in vitro propagation. The sterilization of explants was optimized: 1.6% solution of sodium hypochlorite effectively sterilized plant materials for 10 minutes. Nutrient media composition was evaluated for efficient shoot regeneration. The study examined axillary bud regeneration on Murashige and Skoog medium with different concentrations of hormones. A combination of 6-benzylaminopurine (0.5 mg/L) and gibberellic acid (0.5 mg/L) yielded optimal results, with shoots reaching 3.5 cm. Root induction was analyzed with varying indole-3-acetic acid (IAA) concentrations, and the best results were achieved with 1.5 mg/L IAA, resulting in an 85% rooting frequency. Adapting in vitro plants to ex vitro conditions is crucial given their sensitivity to environmental changes. Well-developed leaves and a robust root system are essential for successful acclimatization during transplantation into a soil substrate. This research provides valuable insights into the critical parameters for a successful transition of in vitro propagated plants to soil conditions, optimizing micropropagation practices.

THE PERSPECTIVITIES OF MICRICLONAL PROPAGATION OF ACER PLATANOIDES L. CRIMSON KING (ACEARCEAE JUSS.)

Clonal micropropagation – massive asexual propagation of plants from cell and tissue culture; the resulting plants are genetically identical to the original copy. The conservation of plants by tissue culture methods is of great interest and will probably become even more common in the future. The advantages of this method are numerous, but we find it most important that the initiation of cultivation requires only a single plant, a seed or a single explant (apex, meristem, bud, piece of leaf, stem etc.), thus, the available plant specimens (which can be only a few) will not be affected by harvesting them from their habitat. The state program “Developing of the scientific basis for the sustainable reproduction of valuable specimens of the botanical garden collection in in vitro culture” is being conducted in the laboratory of biotechnology of the Tashkent Botanical Garden of the Institute of Botany, Academy of Sciences of the Republic of Uzbekistan, directed at microclonal propagation of many valuable species presented in a single copy, as well as species in demand in urban greening programs. Acer platanoides L. Crimson King variety (Acearceae Juss.) is a deciduous, slow-growing tree, reaching 15 m with age. The crown shape is wide-round and even. The leaves are large, 5-7 lobed, deep purple, and do not change color throughout the growing season. The trunk is smooth, dark in color, with clearly defined longitudinal grooves. Because of its graceful shape, the Crimson King variety is extremely popular. It is actively planted in city yards, parks, and roadsides. Suitable for landscaping. Within this state program the protocol of microclonal propagation of A. platanoides Crimson King variety has been developed to propagate this species for Botanical Garden collection as well as for greening programs. Solutions of sodium hypochloride (4-6%), hydrogen peroxide (2-15%), silver nitrate (0.01%), Tween20, ethanol (70%), and some other sterilizing agents were tested for developing a protocol for sterilization of maple explants. “Belizna” solution, “Domestos” sterilizing soap, fungicides difenoconazole, mancoseb and metalaxyl, fludioxonil, propiconazole, antibiotics streptomycin, amoxicillin, gentamicin, and etc. were also implemented for explants sterilization. As a result of the studies, it was determined that the most optimal source of explants are branches with apical (10% regeneration) and lateral (100% regeneration) buds of the annual shoot of A. platanoides Crimson King variety. Plant growth environment is important in the success of in vitro propagation. Thus, explants obtained from trees growing in the arid areas of massive Kuylyuk in Tashkent, were characterized by low viability and a high degree of infection with fungal diseases in comparison with explants obtained from trees growing in Hastimom Square in Tashkent, where trees are watered daily. We found two ways of in vitro propagation of A. platanoides L. variety Crimson King: 1. With the use of microcuttings. 2. Indirect organogenesis with induction of callus. The best way for A. platanoides L. variety Crimson King became indirect organogenesis trough induction of the callus in the WPM - Wood Propagation Media, hormone free or with 6- benzilaminopurine in the media. The duration of the developing of a plant usually takes 6-9 months.

Conservation Potential Trough In Vitro Regeneration of Two Threatened Medicinal Plants Ungernia sewertzowii and U. victoris.

Ungernia sewertzowii (US) and U. victoris (UV) are medicinal plants and sources of biologically active compounds for pharmaceutical needs. The leaves of US contain 0.29-0.81% sum of alkaloids with a predominance of lycorine, which is 0.04-0.46% in leaves and 0.15-0.38% in bulbs. Lycorine is used to treat acute and chronic bronchitis. The leaves of UV contain 0.27-0.71% sum of alkaloids with a predominance of galanthamine-0.13-1.15%. Galanthamine is used to treat mild-to-moderate dementia (Alzheimer's disease). The natural populations of US and UV are in danger as sources of income for local people. To resolve this problem, two protocols for microclonal propagation were developed to replace natural raw materials with in vitro regenerated plants. Callusogenesis of US and UV was induced on Murashige and Skoog (MS) nutrient media with 2.4D (0.5 mg/L) in combination with BAP (0.5 mg/L), Kin (0.5 mg/L), or Zea (0.5 mg/L). Direct (for US) and indirect (for US and UN) organogenesis were observed on MS with BAP (0.5 mg/L) or Kin (0.5 mg/L) in combination with IAA (0.5 mg/L) or NAA (0.5 mg/L). Direct organogenesis resulted in 3-5 bulbs of US on one explant; indirect organogenesis resulted in up to 100-150 bulbs of US and UV on one explant within 6 months, or five to six subcultures after transferring the callus to the nutrient medium. The tissue cultures of US and UV were characterized by very low data on antioxidant activity based on IC50 values for DPPH and ABTS radical scavenging activities, whereas in vitro regenerated plants (leaves and bulbs) had higher data. We concluded that in vitro regenerated plants are valuable sources of lycorine and galanthamine, which allow the protection of the natural populations of these two species from extinction.

Adaptation of regenerant plants representing the genus Hydrangea L. to non-sterile conditions using a hydroponic system

The adaptation of regenerant plants to ex vitro conditions constitutes the final stage of clonal micropropagation for hydrangea. The study used the AirCube Ebb & Flow hydroponic system that periodically floods the plant roots with a nutrient-rich solution. The study examined the effect of three different substrates on the establishment of regenerant plants: agroperlite, coconut substrate, and mineral wool. The establishment of microshoots with the use of the hydroponic system was found to average 85 %. Agroperlite proved to be the most effective substrate for the adaptation of regenerant plants: the average plant establishment amounted to 90 %; the use of mineral wool was shown to be the least effective (81 %). A greater number of plants with full root system development after 15 days of adaptation was noted with the use of agroperlite and coconut substrate. Of all the studied substrates, agroperlite was more effective for root system development (average root length of 5.9 cm), with the coconut substrate being slightly inferior (average root length of 5.4 cm); the use of mineral wool was the least effective (average length of 2.9 cm). The greatest average plant height at day 30 of cultivation was observed in H. arborescens varieties (8.61 cm), while the lowest was noted in the varieties of H. paniculata (4.02 cm). The use of a hydroponic system in the adaptation of regenerant plants was proved to provide a means to obtain the planting material of hydrangea with a developed above-ground part and root system in 30 days.

Clonal micropropagation and ex-situ conservation of Rhycncholaelia digbyana (Lindley) Schltr

Objective: To obtain protocols for clonal micropropagation, crop planning, and in vitro conservation of Rhycholaelia digbyana (Lindley) Schltr. Methodology: The effects of the Kundson C basal medium and benzylaminopurine concentration were evaluated for clonal micropropagation. The treatment with the greatest number of shoots formed per apex was selected for crop planning. Experiments were conducted to determine the effect of basal medium Murashige and Skoog concentration at 2.2 gL-1 and 4.4 gL-1; sorbitol, mannitol, and sucrose at 1, 2, and 3% on slow growth. Results: The best treatment for clonal micropropagation and crop planning was identified as 21.60 gL-1 Knudson C with 8.80 µM benzylaminopurine. This treatment resulted in uniform-sized shoots produced. The multiplication process can yield 10,240 seedlings in 12 months. Slow growth was achieved using Murashige and Skoog basal media at 2.2 gL-1 with 1% mannitol. Implications: More experiments must be conducted to determine the best shoot induction conditions and improve resource efficiency. Conclusions: These findings represent the first report on micropropagation and ex-situ conservation to preserve germplasm for this species as an important resource for the floriculture industry.

Изучение влияния препарата Янтарин в составе питательной среды Мурасиге и Скуга на клональное микроразмножение некоторых сортов земляники садовой

The article presents the results of studies on the influence of different variants of modification of Murashige and Skoog (MS) nutrient medium with the help of preparations of growth-regulating action. The researches were carried out on the basis of the educational and production laboratory of agricultural biotechnology of FGBOU VO Kostroma State Agricultural Academy. Regenerant plants of garden strawberry: Asia and Albion were used as research objects. As research subjects were used: growth regulator of cytokinin nature 6-BAP (6-benzinaminopurine), which is standard in plant biotechnology and growth-stimulating preparation - Yantarine, VRK. In the process of research work, a comparative analysis of the effect of different doses of cytokinin 6-BAP and Yantharin preparation on the growth and reproduction of plants of the studied varieties of garden strawberry was carried out. As a result, it was found that at the stage of clonal micropropagation of garden strawberry varieties Asia and Albion, the use of the preparation Yantarine (10.0 mg/L medium) in the nutrient medium together with cytokinin 6-BAP (0.5 mg/L) and 6-BAP (1.0 mg/L) in comparison with the traditional variant 6-BAP (0.5 mg/L medium) - control did not have a stimulating effect on the increase in height and number of micro rosettes formed by each plant regardless of variety. Keywords: CLONAL MICROPROPAGATION, MULTIPLICATION COEFFICIENT, GARDEN EARTH, VARIETY, GROWTH REGULATOR, IN VITRO

Techniques for increasing the efficiency of microclonal propagation of potatoes (review)

Techniques for increasing the efficiency of microclonal propagation of potatoes (review)

Application of revitalize liquid biocomplex to increase adaptability of grapes at planting in open ground conditions

At present, the range of modern grape varieties suitable for cultivation in the conditions of the Non-Black Earth zone of the Russian Federation is represented by hybrids of different species origin derived from Vitis berlandieri Planch., Vitis Amurensis Rupr., Vitis riparia Michx., Vitis Labrusca L., which are characterized by low ability to vegetative propagation. Therefore, the development of techniques to improve the technology of accelerated propagation of these varieties, including the technology of clonal micropropagation is currently urgent. However, most studies in the field of in vitro propagation of grapes are devoted to laboratory experiments, but there is little information on the influence of the propagation method on the development indicators and vegetative productivity of grape mother plantations in protected and open ground conditions. Therefore, the purpose of this study was to develop methods of application of Revitalize liquid to increase the adaptability and stress resistance of ex vitro grape plants during summer transplanting into the open ground to create mother plantations. The research objectives are to reveal the effectiveness of feeding (root, foliar, combined) with Revitalize liquid during summer transplanting ex vitro grape plants of grape varieties Kishmish № 342, Moscow White and Kober 5BB rootstock into the open ground. The obtained results indicate that double combined treatments (root 500 ml: 500 ml H2O + foliar 25 ml:1000 ml H2O) are effective for pre-growing of ex vitro mother plants of Kishmish № 342 and Kober 5BB rootstock in open ground conditions, and double root feeding (at a concentration of 25 ml:1000 ml H2O) with Revitalize liquid is promising for Moscow White variety.

Influence of growth regulators on microclonal propagation of <em>Scrophularia umbrosa</em> Dumort under <em>in vitro</em> conditions

The possibility of effective microclonal propagation of Scrophularia umbrosa Dumort for producing planting materials, aimed at preservation of the species has been shown. This will aid in the creation of artificial introduction populations of this endangered species in the Republic of Tatarstan, Russia. Optimal conditions for surface sterilization of seeds, development of microshoots, in vitro rooting and acclimatization have been developed. The most effective surface sterilization and germination was achieved with 10 % commercial bleach. Nodal explants were cultured in Murashige and Skoog’s (MS) medium with different concentrations of 6-benzylaminopurine (BAP) and indole-3-acetic acid (IAA). The maximum number of microshoots was developed on MS medium containing 1.0 mg/l of BAP and 1.0 mg/l of IAA. Full strength MS medium with only IAA or together with (indole-3-butyric acid) IBA is optimal for rapid rooting of microshoots. The combination of soil: perlite (2:1) (v/v) was the best for ex vitro acclimatization of plantlets.

Improvement of the clonal micro-propagation technology elements for raspberries of various fruiting types

The results of research on clonal micropropagation of 17 raspberry varieties of the Altai and European selection are presented. Recently, researchers have been focusing on creating a universal nutrient medium that would be equally suitable for any variety of a particular plant species. This is especially important for mass clonal micropropagation in production nurseries. The regeneration potential of the raspberry varieties of different types of fruiting at each stage of reproduction has been assessed. At the stage of actual micropropagation, it was found that Driver and Kuniyuki medium in our modification was superior to the Murashige and Skoog medium in terms of the shoot length and averaged 9.0 mm for common type varieties and 12.3 mm for remontant varieties. This made it possible to eliminate the additional stage of elongation of the microshoots. Also, the appearance of microshoots improved on the new medium. It was found that for raspberry, regardless of its type, the optimal concentrations of the growth regulators lie in the following range: cytokinin 6-benzylaminopurine (BAP) 2.5–3.5 μM together with auxin ß-indolyl butyric acid (IBA) 0.5–0.7 μM. At the stage of rhizogenesis, the best results were shown by the Driver and Kuniyuki medium with 2-fold reduced content of all main components and with the addition of 2.0 μM IBA at the passage duration of 21 days. After that, all microcuttings with and without roots underwent the adaptation stage – growth completion in neutral substrates for 56 days under ex vitro conditions in a vegetation room. In most cases, there were no statistically significant differences in the length and number of leaves regardless of the presence or absence of roots at the initial stage of adaptation. By the end of this stage, 100% of the adapted raspberry plants of the usual type of fruiting and 98% of the remontant type were obtained.

Application of various growth regulators in clonal micropropagation of black currant (Ribes Nigrum L.)

Currently, the optimization and development of new techniques for microclonal reproduction of black currant (Ribes nigrum L.) are one of the traditional objects of research of domestic and foreign scientists. It is noted that the success of reproduction depends on a number of factors: the timing of introduction into culture in vitro, the type of explants, the sterilizing agent, the composition of the nutrient medium. At the same time, the survival and growth of explants at each stage of reproduction depends not only on the salt composition of the nutrient medium, but also on growth regulators, mainly cytokines and auxins. This article discusses the theoretical aspects of the use of various growth regulators at different stages of clonal micropropagation of black currant, provides methods of microclonal reproduction developed by scientists of leading research organizations.

INFLUENCE OF CULTIVATION CONDITIONS ON THE GROWTH AND ACCUMULATION OF BIOLOGICALLY ACTIVE SUBSTANCES OF HYSSOPUS OFFICINALIS L. UNDER IN VITRO CONDITIONS

Introduction. Since ancient times, aromatic plants have been widely used to treat diseases of various natures due to the content of valuable metab-olites and essential oils (EOs). In modern medicine, cosmetology and the food industry, the importance of aromatic plants is also not in doubt; the chemical composition, accumulation features, synthesis and properties of EO are being actively studied. With the development of clonal micropropaga-tion technology, it has become relevant to study the accumulation of biologically active substances in aseptic in vitro culture (microclones and cell cul-tures) under various propagation protocols. Material and methods. Hyssop (Hyssopus officinalis L.) is a common aromatic plant from the family Lamiaceae Martinov. The aerial parts and EO of the plant have a wide range of biological activities - anti-inflammatory, antioxidant, antimicrobial, etc., which determines the use of plant biomass and extracts in food and light industries, medicine, and pharmacology. In this work, the influence of the mineral and hormonal composition of nutrient me-dia on the growth of aseptic plants of two cultivars of Hyssopus officinalis – Lekar and Iney – was studied. Results and conclusion. A comparison was also made of the accumulation of the total flavonoids in an aseptic culture depending on the cultivation mode - the degree of aeration of the culture vessel and the addition of cytokinin or auxin components to the nutrient medium. It was found that the leaves of aseptic plants of Hyssopus officinalis accumulate more flavonoids (up to 3.6 mg/g fresh weight) than the stems (0.3–1.1 mg/g fresh weight for most experimental variants), in addition, the cv. Lekar was significantly richer in compounds of this group (2.7–3.6 mg/g fresh weight in leaves) compared to the cv. Iney (no more than 1.5 mg/g fresh weight in leaves).

Features of clonal micropropagation of plum PK SK 1 clonal rootstock

Methodological features of the main clonal micropropagation stages of plum PK SK 1 clonal rootstock (of NCFSCHVW selection) are described. The rootstock is characterized by a high adaptability to soil and climatic conditions of the region. In particular, it exhibits good winter hardiness, resistance to overwatered soils, tolerance to drought, and the capacity to grow on heavy soils. Plum seedlings on this rootstock develop a powerful root system. These advantages render the development and improvement of methods for clonal micropropagation of plum PK SK 1 clonal rootstock highly relevant. The research was carried out in 2019-2022. The period of active shoot growth, i.e., the first and second decade of may, was established to be the most optimal period for introduction of explants into in vitro culture. In this period, regeneration reaches 78.1–93.8 %. Eff ective shoot multiplication proceeds on MS medium with Fe-EDTA or MS medium with Fe-EDDHA and 6-BAP in the amount of 1 mg/L, with the highest number of shoots formed from one explant following the fourth passage (on average, 11.7 and 12.3 shoots per explant). A signifi cant eff ect of the 6-BAP concentration on the number of shoots formed was observed. The combined eff ect of the form of chelated iron and 6-BAP concentration on the number of shoots formed was established only after 3-5 passages on MS medium with Fe-EDDHA. The rooting stage of PK SK 1 rootstock can also be carried out on a hormone-free MS medium with Fe-EDDHA. The rooting effi ciency reaches 57.1–61.8 %. On average, 2.4 roots are formed per shoot with a length from 1.2 to 5.1 cm, with the root quality being high (not cartilaginous and not brittle). For the adaptation stage, rooted shoots with a height of at least 2 cm having two or more roots with a length of at least 2-3 cm are selected. A mixture of the Agrobalt plant nutrient soil, vermiculite, and perlite in a ratio of 3:1:1 can be used as a substrate. Following four weeks of adaptation, the number of adapted plants averaged 87.5 %.

Optimization of clonal micropropagation of stone fruit crops

The aim of the research was to optimize the clonal micropropagation of stone crops through the use of improved techniques. The objects of the research at the stage of introduction into culture in vitro were meristematic apexes, at the stage of micro-propagation itself – micro-shoots, at the rooting stage – rooted micro-shoots, at the adaptation stage – micro-plants. All experiments were carried out according to generally accepted methods using the example of the steppe cherry variety Shchedraya, the domestic plum variety Kazanskaya and the hybrid sweet cherry Fatezh. As a result of the research, it was found that the use of a 10 % chlorhexidine solution for sterilization of the initial plant material of stone crops increased the survival rate of apexes on average by 2.4 %; the combined use of growth regulators 6-benzylaminopurine 0.5 mg/l, gibberellic acid 0.2 mg/l, indo-lil-3-butyric acid (IBA) 0.2 mg/l in a nutrient medium and an experimental diode pulsed phytoirradiator in the last proliferation passage activated the proliferation of micro-shoots, increasing the reproduction coefficient of stone crops in 6 passages by an average of 0.9 pcs/explant; the addition of 1.0 mg/l (IBA ) to the nutrient medium provided an increase in the rooting capacity of micro-shoots of stone crops by an average of 9.6 %. The treatment of micro-plants of stone crops at the stage of adaptation by spraying with an 8 % solution of the extract of the products of the larvae of the large wax moth and the use of an experimental LED pulsed phytoirradiator with a mixed spectrum contributed to an increase in their survival rate by an average of 12.4 %. Compliance with the proposed improved methods of clonal micropropagation of stone crops using growth regulators and an experimental LED pulse phytoirradiator with a mixed spectrum made it possible to increase the yield of standard adapted micro-plants by 2 times. At the same time, the cost of one adapted micro-plant decreased by an average of 11.4 rubles, and the profitability of obtaining improved stone crop material increased by 33.7 % and amounted to 160.7 %.

Exogenous Cytokinin Induces Callus and Protocorm-Like-Bodies Formation in In Vitro Root Tips of Vanilla planifolia Andrews.

Vanilla is a popular flavouring essence derived from the pods of vanilla orchid plants. Due to the high demand for vanilla flavour, high yielding vanilla plantlets are necessary for establishing vanilla plantations. Clonal micropropagation is a viable technique for the mass production of high yielding vanilla plantlets. This study reports an efficient regeneration protocol by using cytokinin as the sole plant growth regulator to regenerate plantlets from the root tips of a commercial vanilla orchid species, Vanilla planifolia. Most studies to date have reported using seeds and nodes as starting explants for in vitro micropropagation of vanilla orchids. So far, regeneration from roots has not been very successful. Previous studies favoured the use of auxins only or high auxin to cytokinin ratios to induce callus, and sole cytokinins were used for direct shoot regeneration. However, it was sporadically observed in plantlets regeneration of V. planifolia that multiple shoots were regenerated from the tips of intact aerial roots submerged in media. This study therefore investigated the regeneration of excised vanilla root tips through the application of most commonly used auxins (1-naphthaleneacetic acid and 2,4-dichlorophenoxyacetic acid) and cytokinins (6-benzylaminopurine and thidiazuron). High auxin presence is known to promote callusing in in vitro plants. However, in this study, auxin treatment inhibits callusing in root tips. While cytokinin treatments, even at low levels, has promoted high rate of callusing. These callus cells regenerate into protocorm-like-body (PLB) shoots when cytokinin levels are increased to 0.5 mg/mL 6-benzylaminopurine (BAP) under light conditions. The findings of the study have the potential of providing large quantity of high yielding vanilla plantlets through clonal micropropagation.

Клональное микроразмножение лесных ягодных растений рода Rubus

Cloudberry (Rubus chamaemorus L.) and arctic raspberry (Rubus arcticus L.) are highly nutritional and medicinal but lowyield berries, with some populations being on the verge of extinction. Micropropagation biotechnologies are cost-effective and may provide healthy and plentiful planting material for these valuable berries. Clonal micropropagation of cloudberry and arctic raspberry requires new methods adapted for Russian varieties. This research featured the effect of sterilizing agents on the survival rate of explants of R. chamaemorus and R. arcticus, as well as the effect of growth regulators in the nutrient medium on their organogenesis in vitro.
 Berries obtained from regenerant plants of R. chamaemorus (Arkhangelsk and Vologda varieties) and R. arcticus (Sofia and Galina varieties) underwent a biochemical analysis. Further research involved the effect of sterilizing agents and exposure time on the viability of explants, as well as the effect of the nutrient medium composition and the concentration of growth regulators on the development of microshoots and roots in vitro.
 In case of lateral buds, the highest survival rate of both types of explants (80–96%) belonged to the samples sterilized with 0.2% silver nitrate and 5% Lysoformin 3000 for 15 min. In case of etiolated shoots (79–100%), it was the samples treated with 0.2% silver nitrate, 0.01% Nika 2, and 5% Lysoformin 3000 for 10 min. The maximal total length of microshoots in R. chamaemorus (19.4–22.7 cm) was registered at 0.1 mg/L Cytodef in the Murashige and Skoog medium. The maximal total length of roots (46.0–56.6 cm) was obtained when the medium contained 0.5 mL/L indolylacetic acid. As for R. arcticus, the maximal total lengths of microshoots (22.4–22.8 cm) and roots (86.6–89.3 cm) occurred at the same concentrations of growth regulators on 1/2 Murashige and Skoog medium.
 In this research, Cytodef and indolylacetic acid applied in the process of clonal micropropagation of R. chamaemorus and R. arcticus made it possible to increase the yield of high-quality planting material for commercial plantations.

ЭФФЕКТИВНОСТЬ ПРЕПАРАТА МЕЛАФЕН НА РАЗЛИЧНЫХ ЭТАПАХ КЛОНАЛЬНОГО МИКРОРАЗМНОЖЕНИЯ

Application of the drug Melafen was studied at the stages of introduction, proliferation, micro-propagation, adaptation to non-sterile conditions and open ground conditions of grapevine varie-ties of various origins and directions of use. It was found that at the introduction stage, in or-der to improve the survival and regeneration of meristems, the growth regulator Melafen in a concentration of 10-7% should be added to the nutrient medium. Different varietal responses to the use of the drug was noted. The use of Mela-fen at the stage of introducing meristems into culture has a positive effect on the passage of the next stage - micropropagation (proliferation). The positive effect of the drug Melafen was re-vealed in the microcutting of plants of the Tsim-ladar grapevine variety. A clear improvement in all qualitative indicators was noted at concentra-tions of 10-7, 10-9, 10-11%. The best results were obtained at a concentration of 10-7. The variety-specificity of the drug's action to improve the characteristics of plants was noted. The "afteref-fect" of Melafen was found, which is expressed in an improvement in the condition of plants during subculture without Melafen. The length of the rhizogenic zone increased by 1.4–2.5 times, the height of plants by 1.3 times, the growth rate increased, and therefore, there is an acceleration of micro–propagation and, in gen-eral, an increase in the effectiveness of clonal micro-propagation. Improving the qualitative characteristics of plants contributes to the adap-tation process (higher yield of adapted plants) with good plant condition.

Prospects for the creation of new phytochemical medicinal products based on Myrtus communis L. (a review)

The number of medicinal products based on biologically active substances (BAS) of plant origin is increasing every year. Scientists are exploring non-official plant raw materials used in non-traditional medicine to expand the raw material base for creating new phytopreparations. Among numerous plants, common myrtle (Myrtus communis L.), which is a fairly common indoor plant, is recognized as a valuable source of BAS. The aim of the work is to analyze and summarize new literature data on the botanical characteristics, chemical composition, pharmacological and toxicological properties of Myrtus communis L. Materials and methods. Data were collected from several legitimate databases and services such as PubMed, Medline, Scopus, Google Scholar, ResearchGate using the key terms “Myrtus communis L.”, “botanical characteristics”, “pharmacological studies”, “phytochemical studies” in each database data Relevant and related data were filtered as appropriate if deemed relevant to the topic of interest. Time frames have also been adjusted to provide up-to-date information. Results. Myrtus communis L., commonly known as common myrtle, is a widely recognized medicinal plant in the Mediterranean region. Various parts of this plant, including the leaves, fruits, and flowers, have been used in traditional medicine for treating a wide range of ailments. The pharmacological properties of common myrtle are attributed to the presence of essential oils and phenolic compounds, and these properties include antimicrobial, antiviral, antidiabetic, antispasmodic, vasodilator, antiulcer, antioxidant, antitumor, and anti-inflammatory effects. This article offers an overview of the botanical characteristics and chemical composition of different parts of common myrtle, and it presents a literature review of pharmacological studies that provide evidence for the plant’s medicinal properties. Conclusions. Common myrtle is a promising plant for further pharmacognostic research with the aim of expanding the raw material base, using the method of clonal micropropagation and creating new phytopreparations based on it.

ДИНАМИКА РАЗМНОЖЕНИЯ ПОДВОЕВ ВИНОГРАДА В КУЛЬТУРЕ IN VITRO

In connection with the extension of areas under vineyards, it becomes necessary to use rootstocks, resistant to certain soil and climatic conditions (high content of active lime and salts in the soil, drought). Growth of the assortment of rootstocks available for propagation is one of the most important strategies of domestic nursery farming development, along with the production of improved planting material and better performance of its quality indicators. Today it is important to optimize clonal micro-propagation technology for promising grape rootstocks in order to increase net reproduction while maintaining the genetic identity of planting material. The purpose of the work was to study the dynamics of morphogenesis of grape rootstocks in the system in vitro to optimize the technology of clonal micro-propagation, taking into account the genetic specificity of particular genotypes. The study materials were the in vitro plants of grape rootstocks: Fercal clone 242, Ruggeri 140, and Gravesac (clones 11 and 12). The methods accepted in biotechnology and developed in the Breeding Department of the Institute Magarach were both used in the process of research. Cultivation was carried out on PG medium supplemented with NAA (α-naphthylacetic acid) 0.05 mg/l. The results showed that the dynamics of morphogenesis of rootstocks Ferсal clone 242, Gravesac clone 11 and Gravesac clone 12, analyzed on the basis of net propagation, did not differ significantly by varieties, with the exception of the second passage. The study of morphogenetic potential of Ruggeri 140 rootstock bud made it possible to reveal the dependence of net propagation on the line, it was especially noticeable in the first passage. Separate lines showed high net propagation in the second passage. The average indicator value for all lines was 2.59. In general for all rootstocks, similar results were obtained in successive passages, indicating a tendency for net propagation to be decreased. In order to increase the efficiency of technology, it is necessary to optimize the conditions of cultivation for industrial propagation, taking into account the genetic characteristics of every rootstock.