Internodal Segments Research Articles

Indirect in vitro Regeneration in Four Varieties of Potato (Solanum tuberosum L.) from Internodal Segments and Leaf Explants

Internodal segments and leaf explants from four varieties of potato (Solanum tuberosum L.) cultivated in Bangladesh, namely, Asterix, Diamant, Granola and Lady Rosseta were utilized for indirect in vitro regeneration of shoots through callus culture. The best responses regarding the reaeration of shoots were obtained when the explants were cultured on MS medium supplemented with 4.0 mg/l BAP and 1.0 mg/l IAA and 0.5 mg/l GA3. The highest frequency of multiple shoot regeneration was recorded from internodal segments rather than from the leaf explants. Hormone free MS medium was found to be the most effective for healthy root induction from the in vitro raised excised shoots. Following adequate root induction, the in vitro regenerated plantlets were successfully transplanted and established to soil for further growth and development of tubers. Plant Tissue Cult. & Biotech. 34(1): 83-92, 2024 (June)

Scanning electron microscopic and morphological studies on in-vitro derived callus of low-chill peach (Prunus persica L. Batsch)

In this investigation the effect of collection seasons of explants (winter, spring and summer), type of explants (leaf disc and intermodal segments) and length of explants (0.5, 1.0 and 1.5 cm) for callusing in low-chill peach were standardized. The maximum callus induction (97.78%) in the low-chill peach was obtained from the intermodal segments of 0.5 cm in length used as an explant collected during spring season. The structural changes on the surface of the callus (5–7 weeks old yellowish green compact callus) during the progress of somatic embryogenesis of low-chill peach from the both intermodal segment as well as leaf disc derived callus were also examined with the use of scanning electron microscope (SEM). The SEM studies indicated that callus derived from internodal segment explant had the highest frequency of somatic embryos than callus from leaf discs. The SEM investigation, also demonstrated the sequential events/steps leading to low-chill peach somatic embryogenesis which was originating from somatic embryo mother cells through one unicellular pathway. Two types of calli were morphologically distinguished in both leaf disc and intermodal segment generated callus and these were the compact, well organized yellowish green embryogenic callus, containing large number of small, rich cytoplasmic, starch containing meristematic cells and soft and unorganized non-embryogenic callus containing sparsely cytoplasmic, vacuolated, and large cells devoid of metabolic reserves. The present SEM studies clearly demonstrated that somatic cells from peach explants generated callus could develop into fully differentiated somatic embryos through the characteristic embryological patterns of differentiation.

6-Benzylaminopurine mediated indirect organogenesis in Sapindus trifoliatus L. through internodal segments

6-Benzylaminopurine mediated indirect organogenesis in Sapindus trifoliatus L. through internodal segments

Genetic Transformation of Potato without Antibiotic-Assisted Selection

The genetic engineering of plants often relies on the use of antibiotic or herbicide resistance genes for the initial selection of primary transgenic events. Nevertheless, the commercial release of genetically modified crops containing any marker gene encounters several challenges stemming from the lack of consumer acceptance. The development of strategies enabling the generation of marker-free transgenic plants presents an alternative to address public concerns regarding the safety of biotech crops. This study examined the capabilities of highly regenerative potato cultivars to develop transgenic plants without the presence of selective substances in their media. Internodal segments of in vitro potato plants were inoculated with the Agrobacterium strain AGL0 carrying plasmids, which contained the GFP or RFP gene driven by the CaMV 35S promoter to monitor the transformation process by observing in vivo green or red fluorescence. Despite the absence of selective pressure, inoculated explants demonstrated comparable or even higher transient expression compared to experiments based on antibiotic assistant selection. Consequently, under non-selective conditions, non-transgenic, chimeric, and fully fluorescent potato plantlets were concurrently developed. Among the five tested cultivars, the regeneration efficiency of non-chimeric transgenic plants varied from 0.9 (‘Chicago’) to 2.7 (#12-36-42) plants per 100 detached plantlets. Depending on the regenerative characteristics of potato varieties (early, intermediate, or late), a specific time interval can be determined when a blind collection of transgenic plantlets is more successful, streamlining the transformation procedure. The results indicate that the outlined procedure is simple and reproducible, consistently achieving the transformation efficiency of 7.3–12.0% (per 100 inoculated explants) in potato cultivars without selective pressure. The described transformation procedure holds the potential for obtaining cisgenic or intragenic potato plants with new valuable traits that do not carry marker genes.

Filtering property of myelinated internode can change neural information representability and might trigger a compensatory action during demyelination

In this paper, for the first time, we showed that an Internode Segment (INS) of a myelinated axon acts as a lowpass filter, and its filter characteristics depend on the number of myelin turns. Consequently, we showed how the representability of a neural signal could be altered with myelin loss in pathological conditions involving demyelinating diseases. Contrary to the traditionally held viewpoint that myelin geometry of an INS is optimised for maximising Conduction Velocity (CV) of Action Potential (AP), our theory provides an alternative viewpoint that myelin geometry of an INS is optimised for maximizing representability of the stimuli a fibre is meant to carry. Subsequently, we show that this new viewpoint could explain hitherto unexplained experimentally observed phenomena such as, shortening of INS length during demyelination and remyelination, and non-uniform distribution of INS in the central nervous system fibres and associated changes in diameter of nodes of ranvier along an axon. Finally, our theory indicates that a compensatory action could take place during demyelination up to a certain number of loss of myelin turns to preserve the neural signal representability by simultaneous linear scaling of the length of an INS and the inner radius of the fibre.

Increase in ENHANCER OF SHOOT REGENERATION2 expression by treatment with strigolactone-related inhibitors and kinetin during adventitious shoot formation in ipecac.

Increase of ENHANCER OF SHOOT REGENERATION 2 expression was consistent to treatment with kinetin, TIS108, and KK094 in adventitious shoot formation of ipecac. Unlike many plant species, ipecac (Carapichea ipecacuanha (Brot.) L. Andersson) can form adventitious shoots in tissue culture without cytokinin (CK) treatment. Strigolactone (SL) biosynthesis and signaling inhibitors stimulate adventitious shoot formation in ipecac, suggesting their potential use as novel growth regulators in plant tissue culture, but the molecular mechanism of their action is unclear. In this study, we compared the effects of SL-related inhibitors (TIS108 and KK094) and CKs (2iP, tZ, and kinetin) on adventitious shoot formation in ipecac. Exogenously applied SL-related inhibitors and CKs stimulated adventitious shoot formation. Combinations of SL-related inhibitors and kinetin also promoted adventitious shoot formation, but without additive effects. We also analyzed the expression of CK biosynthesis genes in ipecac. TIS108 increased the expression of the ipecac homolog of ISOPENTENYL TRANSFERASE 3 (CiIPT3) but decreased that of LONELY GUY 7 homolog (CiLOG7), presumably resulting in no change in 2iP-type CK levels. KK094 and kinetin increased CiLOG7 expression, elevating 2iP-type CK levels. Among pluripotency- and meristem-related genes, TIS108, KK094, and kinetin consistently increased the expression of ENHANCER OF SHOOT REGENERATION 2 homolog (CiESR2), which has a key role in shoot regeneration, in the internodal segment region that formed adventitious shoots. We propose that CiESR2 might be a key stimulator of adventitious shoot formation in ipecac.

Two Novel Plant-Growth-Promoting Lelliottia amnigena Isolates from Euphorbia prostrata Aiton Enhance the Overall Productivity of Wheat and Tomato.

Euphorbiaceae is a highly diverse family of plants ranging from trees to ground-dwelling minute plants. Many of these have multi-faceted attributes like ornamental, medicinal, industrial, and food-relevant values. In addition, they have been regarded as keystone resources for investigating plant-specific resilience mechanisms that grant them the dexterity to withstand harsh climates. In the present study, we isolated two co-culturable bacterial endophytes, EP1-AS and EP1-BM, from the stem internodal segments of the prostate spurge, Euphorbia prostrata, a plant member of the succulent family Euphorbiaceae. We characterized them using morphological, biochemical, and molecular techniques which revealed them as novel strains of Enterobacteriaceae, Lelliotia amnigena. Both the isolates significantly were qualified during the assaying of their plant growth promotion potentials. BM formed fast-growing swarms while AS showed growth as rounded colonies over nutrient agar. We validated the PGP effects of AS and BM isolates through in vitro and ex vitro seed-priming treatments with wheat and tomato, both of which resulted in significantly enhanced seed germination and morphometric and physiological plant growth profiles. In extended field trials, both AS and BM could remarkably also exhibit productive yields in wheat grain and tomato fruit harvests. This is probably the first-ever study in the context of PGPB endophytes in Euphorbia prostrata. We discuss our results in the context of promising agribiotechnology translations of the endophyte community associated with the otherwise neglected ground-dwelling spurges of Euphorbiaceae.

Induction of organogenesis and callogenesis in Limbarda crithmoïdes L. (Asteraceae) explants cultured on MS media supplemented with various concentrations of Na+ and K+

The present work describes an efficient micropropagation and callus induction protocol of Limbarda crithmoïdes L. (Asteraceae), a halophyte species with medicinal and horticultural interests. The objective was to identify the culture media that support the best organogenesis and callogenic expressions of four types of aerial explants; nodal and internodal segments and leaf portions, by varying the mineral composition of twenty culture media by adding increasing concentrations of Na+ (from 0-100 mM) and K+ (from 0-50 mM). After two months of culture, parameters relating to the various expressions of organogenesis and callogenesis were measured. Results showed that the K+ and Na+ interactions affect the explants development. The combination of high concentrations of Na+ (50, 100 mM) and K+ (50 mM) ions allowed the most important regeneration of the axillary shoots (70.6-100%), root neoformation (82.6-96.1%) and callus induction (76.3-100%). Rooted plantlets with well-developed axillary shoots have been successfully acclimatized with a 93% of survival rate. The selected media would allow a large-scale multiplication of this medicinal species, without adding exogenous phytohormones, and could be used for the micropropagation of other threatened halophyte species or for the production of callus; rich in secondary metabolites.

Jasmonic and Salicylic Acids Enhance Biomass, Total Phenolic Content, and Antioxidant Activity of Adventitious Roots of Acmella radicans (Jacq.) R.K. Jansen Cultured in Shake Flasks.

Acmella radicans (Asteraceae) is a plant native to America. Despite it having medicinal attributes, studies on its phytochemical properties are scarce, and biotechnological studies do not exist for this species. In this study, we established an adventitious root culture from A. radicans internodal segments in shake flasks with indole-3-butyric acid (IBA), and then elicited it with jasmonic acid (JA) and salicylic acid (SA). The total phenolic content and antioxidant activity were evaluated, and a comparison was made using in vitro plantlets and wild plants. Internodal segments with 0.1 mg/L IBA showed 100% root induction and exhibited better growth after transfer to shake flasks with MS liquid culture medium. JA had a significant effect on biomass increase compared to unelicited roots, mainly with 50 µM JA (28%), while SA did not show significant results. Root elicited with 100 µM (SA and JA) showed a 0.34- and 3.9-fold increase, respectively, in total phenolic content (TPC) compared to the control. The antioxidant activity was also significant, and a lower half-maximal inhibitory concentration (IC50) was observed as the AJ concentration increased. Roots elicited with AJ (100 µM) exhibited high antioxidant activity with DPPH (IC50 = 9.4 µg/mL) and ABTS (IC50 = 3.3 µg/mL) assays; these values were close to those for vitamin C (IC50 = 2.0 µg/mL). The TPC and antioxidant activity of in vitro plants and root cultured in shake flasks showed the lowest values in most cases; even the root cultures without elicitation were better than those of a wild plant. In this study, we demonstrated that A. radicans root culture is capable of producing secondary metabolites, while its production and antioxidant activity can be enhanced using jasmonic acid.

THE INFLUENCE OF ENDOGENOUS POLYPHENOLS, PHOTOPERIOD AND MINERAL COMPOSITION OF THE NUTRIENT MEDIUM ON THE FORMATION OF CALLUS TISSUE OF RELIC GYMNOSPERMS SEQUOIA SEMPERVIRENS (D.DON) ENDL.

Relrvance. Sequoia sempervirens (D.Don) Endl. are the tallest relict long–lived plants characterized by a limited range of growth. Valuable sequoia wood is able to accumulate unique secondary metabolites that do not have synthetic analogues. Sequoia plants grow in specialized microecological niches that limit their natural distribution area. It is known that biotic stress is one of the main environmental factors limiting the introduction of valua-ble plant species – possible sources of production of unique metabolites. Limiting environmental factors have a direct impact on the growth, develop-ment and productivity of secondary plant metabolism. Stress-resistant and highly productive plants can be created using cell biotechnology methods, in particular, in vitro cell selection, which is carried out on a callus culture. Therefore, at the first stage, it is necessary to develop in vitro technology for the rapid production of well-proliferating callus tissue. Purpose of the study. To study the effect of the mineral composition of the nutrient medium, photoperiod and endogenous polyphenols on the for-mation of the callus tissue of sequoia (Sequoia sempervirens (D.Don) Endl.) in vitro. Material and methods. The object of the study was Sequoia sempervirens (D.Don) Endl. plants. Callus tissue was obtained from segments of leaf blades and stem internodes, which were isolated from intact plants. Explants were cultured on MS and WPM nutrient medium containing BAP 2.5 mg/l and 2.5 mg/L 2,4-D. The localization of phenolic compounds was studied in the leaves, stems, apical buds of sequoia plants, as well as in callus tis-sue obtained on a nutrient medium with different mineral composition and under different lighting conditions. To do this, histochemical methods were used: for the sum of phenolic compounds, the material was stained with 0.08% Fast Blue reagent raster, a reaction with vanillin reagent in hydrochloric acid vapor was used to study the localization of flavans (catechins and proanthocyanidins). Results. It was found that the applied lighting mode had a significant effect on the intensity of callus tissue formation, its consistency and color. A well-proliferating callus tissue of light yellow color was obtained on two types of nutrient media with no light source. At a 16–hour photoperiod, a dark brown callus tissue was formed, which died during cultivation. As a rule, callus tissue was formed in those places where the localization of phenolic compounds was insignificant. It was found that in the initiated callus cultures grown on the studied nutrient media with no illumination, the content of cells with phenolic compounds was less than that of callus obtained on the same nutrient media, but with the presence of illumination. Conclusion. Sequoia plants have the ability to synthesize polyphenols, including the flavan series, which is preserved under in vitro conditions. The mineral composition of the studied nutrient media does not significantly affect the biosynthetic ability to form polyphenols in vitro cultures and their growth characteristics.

Application of In Vitro Plant Tissue Culture Techniques to Halophyte Species: A Review.

Halophytes are plants able to thrive in environments characterized by severe abiotic conditions, including high salinity and high light intensity, drought/flooding, and temperature fluctuations. Several species have ethnomedicinal uses, and some are currently explored as sources of food and cosmetic ingredients. Halophytes are considered important alternative cash crops to be used in sustainable saline production systems, due to their ability to grow in saline conditions where conventional glycophyte crops cannot, such as salt-affected soils and saline irrigation water. In vitro plant tissue culture (PTC) techniques have greatly contributed to industry and agriculture in the last century by exploiting the economic potential of several commercial crop plants. The application of PTC to selected halophyte species can thus contribute for developing innovative production systems and obtaining halophyte-based bioactive products. This work aimed to put together and review for the first time the most relevant information on the application of PTC to halophytes. Several protocols were established for the micropropagation of different species. Various explant types have been used as starting materials (e.g., basal shoots and nodes, cotyledons, epicotyls, inflorescence, internodal segments, leaves, roots, rhizomes, stems, shoot tips, or zygotic embryos), involving different micropropagation techniques (e.g., node culture, direct or indirect shoot neoformation, caulogenesis, somatic embryogenesis, rooting, acclimatization, germplasm conservation and cryopreservation, and callogenesis and cell suspension cultures). In vitro systems were also used to study physiological, biochemical, and molecular processes in halophytes, such as functional and salt-tolerance studies. Thus, the application of PTC to halophytes may be used to improve their controlled multiplication and the selection of desired traits for the in vitro production of plants enriched in nutritional and functional components, as well as for the study of their resistance to salt stress.

Morphological and agronomic characteristics of winter rye cultivars in connection with their resistance to lodging

Background. Lodging resistance of winter rye is associated with morphological features of the stem. Searching for source material to breed non-lodging high-yielding cultivars requires studying the varietal phenotypic diversity according to morphological characters of the stem that affect the resistance to lodging and the productivity of the ear.Materials and methods. Experiments were carried out in 2017–2020 at the Federal Agricultural Research Center of the North-East (FARC North-East), Kirov. Field resistance to lodging, morphological characteristics of the stem, yield, and ear productivity were evaluated in 16 winter rye cultivars. The study was based on the International COMECON List of Descriptors for the Genus Secale L., and Methodology for the State Variety Trials of Agricultural Crops. The weight of segments of the second lower internodes was measured in 10 plants of each cultivar under laboratory conditions.Results and conclusions. Negative correlations of lodging resistance with stem length (r= –0.55) and the weight of the second lower internode (r = –0.65) were revealed. Ear productivity of rye cultivars was significantly associated with the wall thickness (r = 0.52) and the length of the second lower internode (r = –0.52). According to the results of the path analysis, the main causes of a decrease in lodging resistance were the weight of the segment (P = –0.467) and the length of the second lower internode (P = –0.408), while an increase was connected with the wall thickness of the second lower internode (P = 0.424). The cultivars differed significantly in their resistance to lodging (LSD05 = 0.8). Cvs. ‘Moskovskaya 12’, ‘Tatyana’, ‘Bylina’ and ‘Yantarnaya’ were identified; they are recommended as source material for breeding for lodging resistance.

A novel approach reveals underestimation of productivity in the globally important macroalga, Ascophyllum nodosum

Ascophyllum nodosum (L.) Le Jolis (Fucales, Fucaceae) is a modular intertidal brown alga that has the particularity of forming an air bladder once a year at the apical tip of the growing shoots. This characteristic provides a means for aging and estimating the growth of individuals. While it has long been recognized that growth can occur in older parts of the frond, this has not been properly assessed until now and has largely been overlooked when calculating the productivity of the species. Recent studies have suggested that the growth and elongation of older segments is minimal and thus has been used to infer past environmental conditions. Here we assessed the length and mass of successive internodal segments from 25 sites spread over both sides of the North Atlantic, covering a wide portion of the distribution of the species. By calculating the ratio of the mass and length of a segment divided by the segment produced the following year, we established that internodal segments continue accumulating mass for 1–5 years and increase in length for 1–3 years at most sites. Segments can almost triple their mass during their second year and more than double their length. These results indicate that previous productivity and growth estimates for A. nodosum based on apical growth alone greatly underestimate the true productivity of the species and its role in coastal carbon cycling. Furthermore, because they grow over several years, internodal segments should not be used to infer past environmental conditions or to reconstruct growth patterns over time.

Cytokinin biosynthesis in cyanobacteria: Insights for crop improvement.

Cytokinins, a type of phytohormones that induce division of cytoplasm, have considerable value in agriculture due to their influences on several physiological processes of plants such as morphogenesis, development of chloroplast, seed dormancy, leaf senescence, etc. Previously, it was assumed that plants obtain cytokinin from the soil produced by microbes as these hormones were first discovered in soil-inhabiting bacteria i.e., Agrobacterium tumefaciens. Later, the cytokinin biosynthesis gene, i.e., ipt gene, has been reported in plants too. Though plants synthesize cytokinins, several studies have reported that the exogenous application of cytokinins has numerous beneficial effects including the acceleration of plant growth and boosting economic yield. Cyanobacteria may be employed in the soil not only as the source of cytokinins but also as the source of other plant growth-promoting metabolites. These organisms biosynthesize the cytokinins using the enzyme isopentenyl transferases (IPTs) in a fashion similar to the plants; however, there are few differences in the biosynthesis mechanism of cytokinins in cyanobacteria and plants. Cytokinins are important for the establishment of interaction between plants and cyanobacteria as evidenced by gene knockout experiments. These hormones are also helpful in alleviating the adverse effects of abiotic stresses on plant development. Cyanobacterial supplements in the field result in the induction of adventitious roots and shoots on petiolar as well as internodal segments. The leaf, root, and stem explants of certain plants exhibited successful regeneration when treated with cyanobacterial extract/cell suspension. These successful regeneration practices mark the way of cyanobacterial deployment in the field as a great move toward the goal of sustainable agriculture.

Gene expression profiling before and after internode culture for adventitious shoot formation in ipecac

BackgroundIn ipecac (Carapichea ipecacuanha (Brot.) L. Andersson), adventitious shoots can be induced simply by placing internodal segments on phytohormone-free culture medium. The shoots form locally on the epidermis of the apical region of the segments, but not the basal region. Levels of endogenous auxin and cytokinin transiently increase in the segments after 1 week of culture.ResultsHere, we conducted RNA-seq analysis to compare gene expression patterns in apical and basal regions of segments before culture and after 1 week of culture for adventitious shoot formation. The results revealed 8987 differentially expressed genes in a de novo assembly of 76,684 genes. Among them, 276 genes were upregulated in the apical region after 1 week of culture relative to before culture and the basal region after 1 week of culture. These genes include 18 phytohormone-response genes and shoot-formation-related genes. Validation of the gene expression by quantitative real-time PCR assay confirmed that the expression patterns were similar to those of the RNA-seq data.ConclusionsThe transcriptome data show that expression of cytokinin biosynthesis genes is induced along with the acquisition of cellular pluripotency and the initiation of cell division by wounding in the apical region of internodal segments, that trigger adventitious shoot formation without callusing.

Псевдодеривация Paracraticularia cylindrica (Michelin, 1840) (Porifera, Hexactinellida)

The morphological diversity of diosculumic sponges, known as Paracraticularia cylindrical, results from the fact that many fossils assigned to this species prove to be fragments of the apical segments of internodes (branches) from major colonies that are rarely encountered as totally preserved fossils. The structures of the branch apical segments and the oscula outlines reflect various manifestations of hexactinellida synchronous division conductive to morphological diversity of the descendants, the succeeding complicatedly structured colonial sponges. Some morphs (parataxa) are considered to belong to the species which are mostly fragments of the apical segments from the braches of the Paracraticularia primary colonies.

A Possible Mode of Action of Methyl Jasmonate to Induce the Secondary Abscission Zone in Stems of Bryophyllum calycinum: Relevance to Plant Hormone Dynamics.

Plants can react to environmental stresses through the abscission of infected, damaged, or senescent organs. A possible mode of action of methyl jasmonate (JA-Me) to induce the formation of the secondary abscission zone (SAZ) in the stems of Bryophyllum calycinum was investigated concerning plant hormone dynamics. Internode segments were prepared mainly from the second or third internode from the top of plants with active elongation. JA-Me applied to the middle of internode segments induced the SAZ formation above and below the treatment after 5–7 days. At 6 to 7 days after JA-Me treatment, the above and below internode pieces adjacent to the SAZ were excised and subjected to comprehensive analyses of plant hormones. The endogenous levels of auxin-related compounds between both sides adjacent to the SAZ were quite different. No differences were observed in the level of jasmonic acid (JA), but the contents of 12-oxo-phytodienoic acid (OPDA), a precursor of JA, and N-jasmonyl-leucine (JA-Leu) substantially decreased on the JA-Me side. Almost no effects of JA-Me on the dynamics of other plant hormones (cytokinins, abscisic acid, and gibberellins) were observed. Similar JA-Me effects on plant hormones and morphology were observed in the last internode of the decapitated growing plants. These suggest that the application of JA-Me induces the SAZ in the internode of B. calycinum by affecting endogenous levels of auxin- and jasmonate-related compounds.

Energy infrastructure of evolution for system with infinite number of links with environment

Analytical simulation of spectral features for evolution of biosystem based on the model of system with infinite number of conserved random links with environment is conducted. Assumption of conservation presumes that the links are executed by appropriate continuity equation. Besides, it is believed that any exchange process between system and environment has an energy dimension. The solution for a total energy exchange quantity E, average efficiency of energy exchange ϒ and related entropy S is found. Solution E demonstrates the interlayer spectral structure when the continuous spectrum is interleaved with the quasi-discrete one. In turn, spectrum for entropy S comes in the bandpass quasi-continuous form. The pair nature of discrete points, relation between optimization and discreteness is also demonstrated. Taken altogether above features enable to think on existence of an obligatory energy infrastructure for evolving biosystem. This infrastructure is formed by combination of the spectral elements, such as nodes and internode segments.

In vitro propagation of Passiflora edulis through internodal segments as affected by medium composition

In vitro propagation of Passiflora edulis through internodal segments as affected by medium composition

Protocols for Adventitious Regeneration of Amelanchier alnifolia var. cusickii and Lonicera kamtschatica 'Jugana'.

The aim of this work was to assess the regeneration capacity of Amelanchier alnifolia var. cusickii and Lonicera kamtschatica cv. ‘Jugana’ from different types of explants under various hormonal treatments. The whole leaves, petioles, and internodal segments of in vitro plants were examined as explants. Several plant growth regulators (cytokinins and auxins) were evaluated for their ability to induce adventitious regeneration. Direct and indirect organogenesis was achieved under certain culture conditions in both species. The frequency of shoot regeneration was strongly dependent on concentrations of plant growth regulators in the induction media (L. kamtschatica ‘Jugana’) or concentrations of plant growth regulators in the induction media and type of explant (A. alnifolia var. cusickii). Results showed that leaves were not suitable explants for A. alnifolia var. cusickii. Both species were able to regenerate shoots from internodal segments and petioles. The highest induction of shoots was obtained on Murashige and Skoog (MS) medium enriched with 2 mg/L thidiazuron (TDZ) and 0.5 mg/L indole-3-butyric acid (IBA) for Amelanchier alnifolia and with 1 mg/L TDZ and 0.2 mg/L indole-3-acetic acid (IAA) for L. kamtschatica ‘Jugana’. Obtained adventitious shoots were further proliferated in order to investigate their multiplication capacity. The multiplication of shoots was successful in all cultivars, with the best results reported in A. alnifolia var. cusickii (7.07 shoots/explant on average).