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Cucumis melo "Meloncella fasciata" is cultivated and appreciated locally for its unripe fruits. Seed production of these landraces rely on local farmers but heterogeneity limits rapid scalability of this crop. Plant micropropagation techniques may be an alternative method for propagation but their use is limited by genetic instability. We concentrated on organogenesis from cotyledonary nodes, applying the plant growth regulator 6-benzylaminopurine (BAP) combined with the antibiotic cefotaxime to reduce the negative effects of high cytokinin doses. It was observed that this antibiotic, in addition to limiting contamination, has a stimulatory effect on regeneration in several species including melon. Multiple shoot regeneration was achieved from explants within 30 days of cultivation. Explants regenerated adventitious shoots with all concentrations of BAP and cefotaxime, however efficiency varied significantly. Cefotaxime at a dose of 500 mg/L combined with BAP 0.5 mg/L induced an effect comparable to higher doses of BAP. Reducing BAP concentration was beneficial on shoot development, since excessive cytokinin concentrations can induce somaclonal variation. Thanks to the reduced quantity of BAP, no tetraploid cells could be observed in regenerated plants. We conclude that cefotaxime can be integrated in the propagation process providing multiple advantages including contamination control and reduced chromosomal instability. [ABSTRACT FROM AUTHOR]

The article discusses the development of three new cultivars of Pothos (Epipremnum aureum) through mutation breeding, resulting in 'UF-Ea-0311', 'UF-Ea-0316', and 'UF-Ea-0317'. These cultivars were selected based on leaf variegation and growth characteristics, with unique color patterns and compact growth forms. The cultivars have been patented and licensed for commercial production, offering unique options for indoor foliage plants. The research highlights the importance of somatic embryogenesis in developing new cultivars and the potential for genetic variability in plant cell culture. [Extracted from the article]

Chrysanthemum (Dendranthema × grandiflora Tzvelev) is an attractive plant species that responds well to mutation breeding research conducted worldwide. The isolation and propagation of mutant individuals are very important for detecting mutations in in vitro cultures. Using in vitro cultures, it is easy to isolate solid mutants. In this study, the homogeneous reproductive capacity of selected mutant individuals after irradiation was examined using ray floret cultures at the M1V1 stage, based on various flower colors and architectures. The explant materials were obtained from selected mutant plants with yellow, dark red, orange, and spoon-shaped ray florets cultivated in full bloom. After the determination of an effective sterilization method, the ray florets were cultured in Murashige and Skoog's (MS) media, which contained 0.5 mg L-1 1- Naphthalaneacetic acid (NAA) and 2.0 mg L-1 6-Benzylaminopurine (BAP). The average rate of plantlet regeneration varied depending on the genotype; mutants with yellow-colored flowers generated 0.6 plantlets per explant, those with orange-colored flowers (1.11), those with dark red-colored flowers (1.16), and those with spoon-shaped flowers (2.71). After plant regeneration, plantlets were cultured in a hormone-free MS nutrient medium to ensure full-rooted plant development. The findings of this study showed that in vitro ray floret culture could be used to swiftly and successfully carry out vegetative reproduction of pottype Brandevil mutants, which are more susceptible to in vivo cutting propagation than pot-type Chrysanthemum cultivars. In the propagating material, there were obtained four differently colored somaclonal plants, eleven partial somaclonal plants with incurved-type ray florets, eight somaclonal plants with spatulate-type florets, one somaclonal plant with semi-double-type flower heads, two somaclonal plants with pointed and reflexing ray florets. [ABSTRACT FROM AUTHOR]

Somatic embryogenesis (SE) provides alternative methodologies for the propagation of grapevine (Vitis spp.) cultivars, conservation of their germplasm resources, and crop improvement. In this review, the current state of knowledge regarding grapevine SE as applied to these technologies is presented, with a focus on the benefits, challenges, and limitations of this method. The paper provides a comprehensive overview of the different steps involved in the grapevine SE process, including callus induction, maintenance of embryogenic cultures, and the production of plantlets. Additionally, the review explores the development of high-health plant material through SE; the molecular and biochemical mechanisms underlying SE, including the regulation of gene expression, hormone signaling pathways, and metabolic pathways; as well as its use in crop improvement programs. The review concludes by highlighting the future directions for grapevine SE research, including the development of new and improved protocols, the integration of SE with other plant tissue culture techniques, and the application of SE for the production of elite grapevine cultivars, for the conservation of endangered grapevine species as well as for cultivars with unique traits that are valuable for breeding programs. [ABSTRACT FROM AUTHOR]

Aneuploid somaclonal variants are frequently observed during tissue culture of caladium (Caladium × hortulanum Birdsey), a popular ornamental plant. Certain variants exhibit improved ornamental characteristics, rendering them valuable for future breeding, provided that they maintain genetic uniformity in subsequent vegetative cycles. This study investigated the genetic uniformity, tuber yield potential, and chilling-stress responses of two types of aneuploid caladium somaclonal variants (VT7 and VT9) produced previously in the second vegetative cycle. Morphological characterization revealed that all established plants displayed no observable alterations in leaf coloration, except for two out of 30 (6.67%) VT7 and one out of 14 (7.14%) VT9. Furthermore, VT7 and VT9 displayed relatively consistent distributions of the measured morphological parameters, suggesting a high degree of morphological uniformity of these variants. Further analysis revealed that all assessed plants from VT7 and VT9 exhibited no alteration in relative nuclear DNA content, chromosome number, and simple sequence repeat (SSR) banding patterns except the three newly observed variants. These results indicated relatively high genetic uniformity of the two aneuploid variants in the second vegetative cycle. Compared with the wild caladium, the two aneuploids yielded more tubers with a reduction in average fresh weight. Additionally, both VT7 and VT9 showed improved chilling tolerance relative to wild caladium, as evidenced by enhanced superoxide dismutase (SOD) activity, peroxidase (POD) activity, proline (Pro) content, and maximum photochemical efficiency (Fv/Fm), along with reduced relative electrical conductivity (REC) and malondialdehyde (MDA) content during chilling stress. Consequently, aneuploid somaclonal variants represent valuable resources for genetic studies and cultivar improvement in caladium.Key message: The tuber progeny of aneuploid caladium somaclonal variants exhibited relatively high genetic uniformity, an increased number of tubers, and enhanced chilling tolerance. [ABSTRACT FROM AUTHOR]

Date palm(Phoenix dactylifera L.) holds substantial agricultural, nutritional, and economic significance, particularly in arid and semi-arid regions. Traditional propagation methods, such as offshoot and seed propagation, face limitations including slow growth rates, limited availability of offshoots, and genetic instability, making the adoption of in vitro culture techniques essential for the mass propagation and genetic improvement of Date palm. This comprehensive review delves into the intricacies of in vitro culture protocols for Date palm, focusing on the development of multiple shoot, root, and organ cultures. The review meticulously examines the critical factors influencing each stage of in vitro propagation, including the selection of explants, optimization of culture media, and control of environmental conditions. The efficacy of different plant growth regulators (PGRs), such as cytokinins and auxins, in promoting shoot proliferation, root induction, and organogenesis is compared and analyzed, highlighting the optimal concentrations and combinations for successful tissue culture outcomes. For multiple shoot induction, the review discusses the use of shoot tips, axillary buds, and immature inflorescences, with media formulations like MS, B5, and WPM supplemented with specific PGRs such as BAP and kinetin. The process of root induction is examined, emphasizing the role of auxins like IBA and NAA in developing robust root systems and the influence of environmental factors like light and temperature. Organ culture techniques, particularly embryogenic callus induction and somatic embryogenesis, are explored, detailing the use of high auxin concentrations for callus formation and the transition to media with balanced PGRs for embryo maturation. Additionally, the review addresses the challenges of somaclonal variation and genetic stability in tissue culture, proposing strategies for monitoring and mitigating these issues through genetic and epigenetic analyses. The potential of integrating advanced biotechnological tools, such as CRISPR/Cas9, for precise genetic modifications is discussed, alongside the need for improved acclimatization protocols to enhance the survival rates of in vitro propagated plantlets. Future research directions are identified, focusing on minimizing somaclonal variation, optimizing acclimatization, exploring diverse explant sources, and scaling up production through automated culture systems. By synthesizing the latest research findings and offering detailed comparisons of various in vitro protocols, this review aims to provide a valuable resource for researchers and practitioners seeking to enhance the efficiency and success of Date palm micropropagation, ultimately contributing to the sustainable cultivation and genetic improvement of this vital crop. [ABSTRACT FROM AUTHOR]

Etlingera elatior is a promising ornamental horticultural species with various purposes such as medicinal, antibacterial agent, culinary, ornamental, and floral arrangement. The increasing demand for more variation has led to the improvements of E. elatior via tissue culture technology. Somaclonal variation helps to overcome the lack of variation of this species due to asexual propagation. The aims of this study are to induce callus and shoot and to detect genetic variations using ISSR markers. The results showed that the Murashige & Skoog (MS) basal medium supplemented with glucose and 1.5 mg L-1 6-benzylaminopurine (BAP) and 3 mg L-1 2,4-dichlorophenoxyacetic acid (2,4-D) produced significantly higher callus percentage, 50% after 20 weeks of culture. The friable calluses were then transferred to shoot induction media containing different concentrations of different BAP, 1-naphthaleneacetic acid (NAA) and thidiazuron (TDZ). After 12 weeks in shoot induction media, a root-like structure was observed in calluses masses T11 (0.1 mg L-1 NAA and 0.3 mg L-1 TDZ). Seven ISSR primers were used to evaluate the genetic variation of calluses. Seventy-two bands were generated, of which 51 bands were polymorphic with an average percentage of polymorphic bands of 72%. Jaccard’s coefficient of similarity values recorded between 0.3529 and 0.4762 exhibited the level of genetic variation among calluses. In short, the explants were affected by different concentrations of auxin and cytokinin for callus induction. ISSR markers revealed the occurrence of genetic variation during callus and shoot induction processes, suggesting a potential to generate new variants using tissue culture.

This study examines the effect of ultraviolet-B (UV-B) and ultraviolet-C (UV-C) radiation on contamination rate and shoot proliferation of Tamban pineapple crown explant. The experimental design was nested and completely randomized with a separate control. The first factor was the type of UV light, namely UV-B and UV-C. The second factor was the duration of UV light exposure, namely 10, 20, 30, and 40 min. This study was carried out from March to June 2023 at the Plant Tissue Culture Laboratory, Faculty of Agriculture, Lambung Mangkurat University, South Kalimantan, Indonesia. Observations were made on the contamination percentage, survival percentage, time of first shoot formation, percentage of explants able to regenerate shoots, and number of shoots. The results showed that UV light treatment decreased the contamination rate. Increasing the duration of UV light exposure decreased the contamination rate, delayed the formation of the first shoot, and affected the number of shoots. UV-B light exposure produced a higher number of shoots than UV-C light. These results suggest that UV-B and UV-C radiation have the potential to optimize surface sterilization protocol and promote somaclonal variation. [ABSTRACT FROM AUTHOR]

In the world's flower trade, gladiolus (Gladiolus spp.) is ranked first among bulbous flowers and eighth among cut flowers, with more than 30,000 different cultivars being grown. Mass multiplication and commercialization are restricted by the traditional propagation methods. However, the large-scale proliferation and improvement of the gladiolus have been accomplished with the aid of plant tissue culture and other biotechnological techniques. The current review includes a thorough examination of the growth and development parameters required for successful in vitro gladiolus development as well as cormel formation. Moreover, focus is being given to various techniques and methods such as in vitro cytogenetic stability and modification of chromosome number, in vitro mutagenesis and selection of pest resistance, in vitro identification and selection to develop virus-free germplasm, cryopreservation, synthetic seed technology, identifying virus diseases by RT-PCR, somaclonal variation, and protoplast and somatic hybridization. Molecular markers and their applications for genetic diversity analysis, relationships between different genotypes, and clonal stability analysis in Gladiolus species have been conducted by several research groups worldwide and are also being discussed. The article also covers efforts to enhance the functionality of plant phenotypes through genetic transformation. Future prospects for further improvement of ornamental gladiolus are also explored. Overall, the current review provides insight into the applications of basic and advanced biotechnological tools for gladiolus improvement. [ABSTRACT FROM AUTHOR]

Somaclonal variants with valuable agronomic traits play a crucial role in crop breeding, provided that they are stably passed down in subsequent generations. Although numerous somaclonal variants have been identified and studied among in vitro regenerated plants in the foliage plant caladium (Caladium × hortulanum Birdsey), no research has been carried out to evaluate their genetic stability in subsequent generations. This study aimed to evaluate the genetic stability of three types of diploid caladium somaclonal variants, previously derived from in vitro callus cultures, over three successive tuber-propagated generations. The analysis of quantitative morphological characteristics revealed a greater degree of variation among the established plants in the first generation (G1) compared to the second (G2) and third generations (G3). Seven plants exhibiting distinct leaf coloration changes were identified in the G1 generation and were found to be stably passed down to the subsequent G2 and G3 generations. These findings indicate a wide range of morphological variation in the G1 generation, followed by relative stability in subsequent generations. A comprehensive cytological and molecular analysis revealed that five of the seven newly observed variants displayed notable differences in relative nuclear DNA content, chromosome number, or SSR (simple sequence repeat) banding patterns compared to their corresponding normal counterparts. The findings of this study will be instrumental in developing new cultivars with distinctive plant morphology through the exploitation of somaclonal variation in caladium. [ABSTRACT FROM AUTHOR]

The efficiency and method of regeneration in in vitro culture conditions depend primarily on the plant growth regulators (PGRs) used. Even growth regulators belonging to one group may have different effects, stimulating the process of direct or indirect organogenesis, thus possibly disturbing the genetic stability among regenerants. The main aim of this study was to identify the genetic stability of Scutellaria baicalensis regenerates obtained by in vitro culture method using start codon targeted (ScoT) markers. S. baicalensis nodal explants were regenerated on MS medium supplemented with kinetin (KIN) at concentrations of 0.25, 0.5, 1.0, and 2.0 mg × dm−3 or benzylaminopurine (BAP)—0.25, 0.5, 1.0, and 2.0 mg × dm−3. The effects of the number of propagated shoots, length, number of nodes, and fresh mass of regenerants were assessed. Moreover, the genetic stability of the regenerants was analyzed using start codon targeted (SCoT) markers. Direct shoot organogenesis was observed on an MS medium containing kinetin, while indirect shoot induction occurred on an MS medium supplemented with BAP. The highest average number of shoots (3.6) was achieved for the MS + KIN medium at a concentration of 0.25 and 5.8 for the MS + BAP 1.0 medium. The average length and average number of nodes were the highest on the MS + BAP 0.25 medium (50.0 and 6.0, respectively), while the lowest values of these features were observed on the MS + KIN 2.0 medium (40.3 and 4.9, respectively). A total of 111 amplified bands were exhibited by SCoT primers. Three of the analyzed primers revealed four unique genotype-specific markers. The average percentage of polymorphism obtained was 36.7%. The analysis of genetic similarity revealed a high level of genetic similarity between the donor plant and regenerants obtained on MS "0" (medium without the addition of phytohormones). A slightly lower value of genetic similarity was observed for regenerants obtained by direct organogenesis (MS + KIN medium at all concentrations). Indirect shoot organogenesis observed on the MS + BAP medium (all concentrations) resulted in the highest differentiation, both in relation to the donor plant and MS "0" regenerants. The results of our work indicate that, in the case of S. baicalensis, the maintenance of genetic stability depends primarily on the presence of the cytokinin type in the medium. [ABSTRACT FROM AUTHOR]

Plants, known for their immobility, employ various mechanisms against stress and damage. A prominent feature is the formation of callus tissue—a cellular growth phenomenon that remains insufficiently explored, despite its distinctive cellular plasticity compared to vertebrates. Callus formation involves dedifferentiated cells, with a subset attaining pluripotency. Calluses exhibit an extraordinary capacity to reinitiate cellular division and undergo structural transformations, generating de novo shoots and roots, thereby developing into regenerated plants—a testament to the heightened developmental plasticity inherent in plants. In this way, plant regeneration through clonal propagation is a widely employed technique for vegetative reproduction. Thus, exploration of the biological components involved in regaining pluripotency contributes to the foundation upon which methods of somatic plant propagation can be advanced. This review provides an overview of the cellular pathway involved in callus and subsequent de novo shoot formation from already differentiated plant tissue, highlighting key genes critical to this process. In addition, it explores the intricate realm of epigenetic regulatory processes, emphasizing the nuanced dynamics of DNA methylation that contribute to plant regeneration. Finally, we briefly discuss somaclonal variation, examining its relation to DNA methylation, and investigating the heritability of epigenomic changes in crops. [ABSTRACT FROM AUTHOR]

The propagation of arabica coffee (Coffea arabica L.) seedlings through indirect primary embryogenesis has significant potential to produce many healthy seedlings relatively quickly. However, there is a concern that plant growth regulators (PGRs) applied in the culture media could result in somaclonal variations. To address this issue, the appropriate concentration of PGR needs to be identified to increase the success of the somatic embryogenesis process of propagation while preventing somaclonal variations. This study aimed to develop a protocol for the propagation of C. arabica through indirect somatic embryogenesis and evaluate somaclonal variation in plantlets derived from somatic embryogenesis, considering the genotype and PGR used. Three cultivars of coffee, i.e., AS2K, S-795, and Sigarar Utang, and two types of PGRs (2,4-D and 2-iP) at different combination concentrations, were used as the factorial experimental design. The concentration of PGRs was 4.52 and 9.04 µM for 2,4 D and 4.93, 9.86, 14.79, 19.72, and 24.65 µM for 2-iP. All combinations were replicated 10 times. The findings revealed that PGRs influenced percentage of callus formation which ranged from 87.02% to 93.81%, while coffee cultivars significantly impacted the development of torpedoes and germination of somatic embryos with the number of torpedoes and germinated somatic embryos were 32.20-94.20 and 21.10-82.20 for 'AS2K', 37.90-62.90 and 27.70-50.20 for 'S-795', and 39.40-72.00 and 29.60-60.60 for 'Sigarar Utang', respectively. Among the PGRs evaluated, the combination of 4.52 µM 2,4-D and 19.72 µM 2-iP demonstrated the highest efficacy with 94.20 torpedoes and 82.20 germinated somatic embryos for 'AS2K', whereas 4.52 µM 2,4-D and 14.79 µM 2-iP were preferred for 'S-795' and 'Sigarar Utang'. Furthermore, molecular analysis using 10 SSR primers of the resulting plantlets indicated no evidence of somaclonal variation. [ABSTRACT FROM AUTHOR]

In vitro culture allows the production of numerous plants with both desirable and undesirable traits. To investigate the impact of the propagation method on highbush blueberry plants, an analysis was performed on four groups of differentially propagated plants: in vitro with axillary (TC-Ax) or adventitious shoots (TC-Ad), conventionally (SC) and using a mixed method (TC/SC). The analysis included plant features (shoot length and branching, chlorophyll and fluorescence and DNA methylation) and fruit properties (antioxidant compounds). The data obtained indicated significant differences between plants propagated conventionally and in vitro, as well as variations among plants derived from in vitro cultures with different types of explants. SC plants generally exhibited the lowest values of morphological and physiological parameters but produced fruits richest in antioxidant compounds. TC/SC plants were dominant in length, branching and fluorescence. Conversely, TC-Ax plants produced fruits with the lowest levels of antioxidant compounds. The methylation-sensitive amplified polymorphism (MSAP) technique was employed to detect molecular differences. TC-Ad plants showed the highest methylation level, whereas SC plants had the lowest. The overall methylation level varied among differentially propagated plants. It can be speculated that the differences among the analysed plants may be attributed to variations in DNA methylation. [ABSTRACT FROM AUTHOR]

Copyright of Egyptian Journal of Botany is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The purpose of this study was to see how different mammalian sex hormones, combinations and levels (progesterone, estrone, testosterone and 17β-estradiol) affected somaclonal variation in tissue culture, as well as to look into the utility of molecular markers (Inter primer binding site—IPBS) in sorting off types/somaclones. The results show that all hormones and binary hormone combinations cause somaclonal variation. The use of two hormones was found to cause minimal and maximal somaclonal variations. The combination of 10–6 mM progesterone + 10–5 mM estrone (6P + 5E) which causes minimal somaclonal variation is the similarity with the control and 65.36% and the positive and very significant correlation with the control (0.0168**, Spearman). The combinations 10–6 mM 17β-estradiol + 10–5 mM estrone of (6B + 5E) which causes maximum somaclanal variation is the similarity with control 55.82%, this combination showed insignificant and negative correlation (–0.061, Spearman) with the control. Furthermore, inter primer binding site (IPBS) was able to link a marker to a trait of interest. As a result, these findings indicate that molecular markers can be an important tool in sorting variation at an early stage. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan Agricultural Sciences is the property of Editorial Board of Journal of Henan Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Determination of the somaclonal variation of in vitro-propagated plants is crucial to determine the appropriate micropropagation protocol and growth regulators for commercial scale multiplication. In this research, nine multiplication media (MM) augmented with different concentrations of 6-benzyl adenine (BA), Kinetin (Kin), and Thidiazuron (TDZ), Three rooting media (RM) supplemented with three levels of α-naphthalene acetic acid (NAA) and three types of soil mixtures (v/v); Coco peat/Vermiculite/Sand (CVS), Peat moss/Perlite/Sand (PPS) and Peat moss/Perlite (PP) were used in the micropropagation protocol of daylily plants. MM2 showed the maximum shoot length and the number of leaves, while MM9 showed the maximum number of shoots. The RM1 showed the maximum root length and the number of roots. During acclimatization, CVS, PPS, and PP soil mixture showed similar performance except the CVS mixture showed lower performance regarding plant height and diameter. The genetic fidelity of micropropagated plants was evaluated using Start Codon Targeted (SCoT) Markers. Six SCoT primers amplified 51 scorable bands with an approximate range from 146 bp to 1598 bp size. Thirty one out of 51 loci were presented in the mother plants. 40 loci were polymorphic, 11 were monomorphic and 7 were unique. The amplification patterns of the micropropagated plants demonstrated genetic integrity to the mother plant ranging from 84.32 to 47.06 and somaclonal variations ranging from 52.94 with 5 mg/l BA pathway to 15.68 with 1mg/l TDZ pathway, thus demonstrating that the homogeneity and the variation of the micropropagated plants affected by the type and the quantity of the plant growth regulator used during multiplication subcultures. This research can be successfully used for other ornamental and medicinal plants' bulk multiplication, germplasm conservation, and future genetic improvement. [ABSTRACT FROM AUTHOR]

A modified cry9Aa2 gene under the transcriptional control of the CaMV 35S promoter was transferred to four potato cultivars ('Iwa', 'Karaka', 'Pacific' and 'Red Rascal') using Agrobacterium-mediated gene transfer. Field plots were established for 170 independently regenerated transgenic lines derived from 113 transformation events. Phenotypic changes such as stunted plants, reduced vigour and/or leaf puckering, were observed in 29% of these lines. Foliage from the remaining 117 lines inhibited larval growth of potato tuber moth (Phthorimaea operculella Zeller) compared with non-transgenic controls. A high correlation was observed between greenhouse- and field-grown foliage for insect resistance using a detached leaf bioassay. Independently regenerated lines recovered from the same transformation event exhibited similar insect resistance. However, these lines derived from the same transformed cell differed markedly in phenotypic appearance and tuber yield. The first shoot regenerated from each transformation event was equivalent to the non-transgenic control for yield traits in only eight transformation events. A further 19 transformation events exhibited agronomic performance equivalent to the non-transgenic control when the second or subsequent regenerated shoots were evaluated. In clonal crops, multiple shoots from each transformation event should be independently assessed to ensure recovery of high-performing transgenic lines. [ABSTRACT FROM AUTHOR]

Somaclonal variation was studied by whole-genome sequencing in rice plants (Oryza sativa L., ‘Nippon‐ bare’) regenerated from the zygotes, mature embryos, and immature embryos of a single mother plant. The mother plant and its seed-propagated progeny were also sequenced. A total of 338 variants of the mother plant sequence were detected in the progeny, and mean values ranged from 9.0 of the seed-propagated plants to 37.4 of regenerants from mature embryos. The natural mutation rate of 1.2 × 10–8 calculated using the vari‐ ants in the seed-propagated plants was consistent with the values reported previously. The ratio of single nucleotide variants (SNVs) among the variants in the seed-propagated plants was 91.1%, which is higher than 56.1% previously reported, and not significantly different from those in the regenerants. Overall, the ratio of transitions to transversions of SNVs was lower in the regenerants as shown previously. Plants regenerated from mature embryos had significantly more variants than different progeny types. Therefore, using zygotes and immature embryos can reduce somaclonal variation during the genetic manipulation of rice. [ABSTRACT FROM AUTHOR]

The efficiency and method of regeneration in in vitro culture conditions depend primarily on the plant growth regulators (PGRs) used. Even growth regulators belonging to one group may have different effects, stimulating the process of direct or indirect organogenesis, thus possibly disturbing the genetic stability among regenerants. The main aim of this study was to identify the genetic stability of Scutellaria baicalensis regenerates obtained by in vitro culture method using start codon targeted (ScoT) markers. S. baicalensis nodal explants were regenerated on MS medium supplemented with kinetin (KIN) at concentrations of 0.25, 0.5, 1.0, and 2.0 mg × dm−3 or benzylaminopurine (BAP)—0.25, 0.5, 1.0, and 2.0 mg × dm−3. The effects of the number of propagated shoots, length, number of nodes, and fresh mass of regenerants were assessed. Moreover, the genetic stability of the regenerants was analyzed using start codon targeted (SCoT) markers. Direct shoot organogenesis was observed on an MS medium containing kinetin, while indirect shoot induction occurred on an MS medium supplemented with BAP. The highest average number of shoots (3.6) was achieved for the MS + KIN medium at a concentration of 0.25 and 5.8 for the MS + BAP 1.0 medium. The average length and average number of nodes were the highest on the MS + BAP 0.25 medium (50.0 and 6.0, respectively), while the lowest values of these features were observed on the MS + KIN 2.0 medium (40.3 and 4.9, respectively). A total of 111 amplified bands were exhibited by SCoT primers. Three of the analyzed primers revealed four unique genotype-specific markers. The average percentage of polymorphism obtained was 36.7%. The analysis of genetic similarity revealed a high level of genetic similarity between the donor plant and regenerants obtained on MS “0” (medium without the addition of phytohormones). A slightly lower value of genetic similarity was observed for regenerants obtained by direct organogenesis (MS + KIN medium at all concentrations). Indirect shoot organogenesis observed on the MS + BAP medium (all concentrations) resulted in the highest differentiation, both in relation to the donor plant and MS “0” regenerants. The results of our work indicate that, in the case of S. baicalensis, the maintenance of genetic stability depends primarily on the presence of the cytokinin type in the medium.

• Reports long term clonal fidelity validation of M. acuminata. • Determination of quercetin, p -coumaric acid and eugenol within various tissues using HPTLC. • Assessment of anti- bacterial activity of various plant parts against prominent strains. • Validation of genetic conformity using SCoT and CBDP-gene targeted markers. • Model approach for other terrestrial orchids. Malaxis acuminata D. Don [ = Crepidium acuminatum (D. Don) Szlach.] is one of the prized medicinal orchids with large-scale application in various nutraceutical and herbal preparations. However, due to paucity in the availability of plant materials, its usage is often restricted. In order to ensure continuous supply of raw material for the pharmaceutical and herbal industries, plant tissue culture plays a crucial role. In the present research, transverse thin cell layer (t -TCL) derived in vitro cultures of M. acuminata were initiated and maintained in Murashige and Skoog (MS) medium supplemented with 1.5 mg/l meta -topolin (m T), 5.0 mg/l chitosan, 1.5 mg/l indole-3- butyric acid (IBA) and 5.0 mg/l phloroglucinol (PG) for three years time period under culture room conditions by regular intermittent sub-culturing. However, the success of in vitro propagated plant bio-resources are often adversely impacted due to the occurrence of clonal variations which is considered as a serious limitation for the commercial utilization. In order to ascertain the clonal fidelity of the long term - propagated in vitro lines of M. acuminata , genetic homogeneity amongst the regenerated plantlets was accessed using two advanced gene targeted molecular markers namely start codon targeted (SCoT) and CAAT box derived polymorphism (CBDP). The plants were found to exhibit 93.34% clonal fidelity in comparison to their mother plant. Keeping in consideration the therapeutic attributes of M. acuminata , the phytochemical makeup of the wild and in vitro - derived plant parts was compared using high performance thin layer chromatography (HPTLC) technique. Furthermore, M. acuminata is considered to be one the most precious medicinal orchids having rich reserves of biomolecules which can be used against various pathogenic bacterial strains. The antibacterial activities of various tissue extracts of M. acuminata were also evaluated against the opportunistic bacterial strains viz. Escherichia coli (MTCC43), Salmonella typhimurium (MTCC733), Staphylococcus aureus (MTCC96) and Bacillus subtilis (MTCC121). The results of antibacterial assays demonstrated the therapeutic efficacy of the in vitro - derived plant parts at identical magnitude with that of their wild counterparts. The present research provides a holistic insight into the clonal stability of the long term - propagated in vitro plants of M. acuminata with promising antibacterial activity. This study can also serve as a model approach for the maintenance of genetically stable in vitro lines of therapeutically important endangered orchid species over a period of time. [ABSTRACT FROM AUTHOR]

Simple Summary: While micropropagation systems have been developed for cannabis, little attention has been given to the potential impact of explant source within the plant on subsequent growth and development in vitro. From other species, it is known that the explant source can have a significant impact on future development, presumably due to variations in endogenous phytohormones, sugars, and epigenetic state. This study was performed using a high-cannabinoid cultivar of cannabis, an economically important crop, to compare the growth and development of explants collected from various positions within the plant, ranging from the top to the bottom. Our results show that the multiplication rate (i.e., number of nodes), especially with explants derived from middle and apical parts of the mother plant, decreased over multiple subcultures, which can result from epigenetic machinery. In contrast, explants derived from the basal portion of the plant had an acceptable multiplication rate throughout the experiment and produced cannabis plantlets with shorter but wider leaves, indicative of rejuvenation. Hence, these results suggest that basal-derived cannabis explants should be used preferentially as starting material for in vitro propagation. Drug-type cannabis is often multiplied using micropropagation methods to produce genetically uniform and disease/insect-free crops. However, micropropagated plantlets often exhibit phenotypic variation, leading to culture decline over time. In cannabis, the source of these changes remains unknown, though several factors (e.g., explant's sources and prolonged in vitro culture) can result in such phenotypical variations. The study presented herein evaluates the effects of explant sources (i.e., nodal segments derived from the basal, near-basal, middle, and apical parts of the greenhouse-grown mother plant) over multiple subcultures (4 subcultures during 235 days) on multiplication parameters and leaf morphological traits of in vitro cannabis plantlets. While initial in vitro responses were similar among explants sourced from different regions of the plant, there were significant differences in performance over the course of multiple subcultures. Specifically, explant source and/or the number of subcultures significantly impacted plantlet height, number of nodes, and canopy surface area. The explants derived from the basal and near-basal parts of the plant resulted in the tallest shoots with the greatest number of nodes, while the explants derived from the middle and apical regions led to shorter shoots with fewer nodes. Moreover, the basal-derived explants produced cannabis plantlets with shorter but wider leaves which demonstrated the potential of such explants for in vitro rejuvenation practices with minimal culture decline. This study provides new evidence into the long-term impacts of explant source in cannabis micropropagation. [ABSTRACT FROM AUTHOR]

The instability of in vitro cultures may cause genetic and epigenetic changes in crops called somaclonal variations. Sometimes, these changes produce beneficial effects; for example, they can be used in breeding programs to generate new cultivars with desirable characteristics. In this article, we present a systematic review designed to answer the following question: How does somaclonal variation contribute to plant genetic improvement? Five electronic databases were searched for articles based on pre-established inclusion and exclusion criteria and with a standardized search string. The somaclonal variation technique has been most frequently applied to ornamental plants, with 49 species cited in 48 articles, and to the main agricultural crops, including sugarcane, rice, banana, potato and wheat, in different countries worldwide. In 69 studies, a technique was applied to evaluate the genetic diversity generated between clones, and, in 63 studies, agronomic performance characteristics were evaluated. Other studies are related to resistance to pathogens, ornamental characteristics and resistance to abiotic stresses. The application of the plant growth regulators (PGRs) benzylaminopurine (BAP) and dichlorophenoxyacetic acid (2,4-D) was the most common method for generating somaclones, and randomly amplified polymorphic DNA (RAPD) molecular markers were the most commonly used markers for identification and characterization. Somaclonal variation has been used in genetic improvement programs for the most economically important crops in the world, generating genetic diversity and supporting the launch of new genotypes resistant to diseases, pests and abiotic stresses. However, much remains to be explored, such as the genetic and epigenetic mechanisms from which somaclonal variation is derived. [ABSTRACT FROM AUTHOR]

Somaclonal variations in tissue cultures can be used in plant breeding programs. However, it is still unclear whether somaclonal variations and their original parent have differences in volatile compounds, and the candidate genes which result in the differences in volatile compounds also need to be identified. In this study, we utilized the 'Benihoppe' strawberry and its somaclonal mutant 'Xiaobai', which has different fruit aromas compared with 'Benihoppe', as research materials. Using HS-SPME-GC-MS, 113 volatile compounds have been identified in the four developmental periods of 'Benihoppe' and 'Xiaobai'. Among them, the quantity and content of some unique esters in 'Xiaobai' were much higher than that in 'Benihoppe'. In addition, we found that the contents and odor activity values of ethyl isovalerate, ethyl hexanoate, ethyl butyrate, ethyl pentanoate, linalool, and nerolidol in the red fruit of 'Xiaobai' were much higher compared with 'Benihoppe', which may result from the significantly increased expression of FaLOX6, FaHPL, FaADH, FaAAT, FaAAT1, FaDXS, FaMCS, and FaHDR in 'Xiaobai'. However, the content of eugenol in 'Benihoppe' was higher than that in 'Xiaobai', which may result from the higher expression of FaEGS1a in 'Benihoppe' compared with 'Xiaobai'. The results provide insights into the somaclonal variations that affect the volatile compounds in strawberries and can be used for strawberry quality improvement. [ABSTRACT FROM AUTHOR]

Simple Summary: Salix myrtilloides is a relict species endangered with extinction in many Central European countries. To save the populations on the southern border of its range, in vitro propagation was used for plants production because it allows one to obtain a lot of new plants in a relatively short time without damaging the existing ones. We collected shoot pieces and multiplied them in a growing media, which contained nutrients and growth regulators. When we produced enough daughter plants, we planted them into soil and hardened them to natural conditions. Based on the conducted genetic analysis and flow cytometry, we stated that obtained plants are genetically identical to the mother ones. The conducted research confirmed that tissue culture may be used to propagate the endangered S. myrtilloides species and that the obtained plants may be used to establish new populations or to strengthen the existing ones. Salix myrtilloides L. is a relict species, threatened with extinction in many European countries. To prevent the loss of the species, tissue culture was established to produce plant material for reintroduction in natural habitats. Micropropagation was chosen as a method to obtain new plants. S. myrtilloides shoots were disinfected with NaOCl, AgNO3, or with a two-step disinfection with NaOCl, and then placed on MS medium supplemented with BA at 1 mg·dm−3 and IBA at 0.1 mg·dm−3. Regenerated shoots were cultivated in presence of BA, KIN, and 2iP to select the treatment with the highest multiplication rate. The obtained plants were acclimatized to ex vitro conditions. Inter-simple sequence repeat (ISSR) and flow cytometric analyses were conducted on in vitro regenerated plants to check their genetic stability. The best disinfection results were obtained when explants were treated with 1.5% NaOCl for 20 min. The highest multiplication rate and good quality plants were noted in the control media, without growth regualtors and in presence of kinetin at 0.5 mg·dm−3. Flow cytometry and ISSR analyses confirmed genetic stability in plantlets, which indicated the possibility to use the in vitro obtained plants for reintroduction. [ABSTRACT FROM AUTHOR]

Starch content is one of the major quality criteria targeted by potato breeding programs. Traditional potato breeding is a laborious duty due to the tetraploid nature and immense heterozygosity of potato genomes. In addition, screening for functional genetic variations in wild relatives is slow and strenuous. Moreover, genetic diversity, which is the raw material for breeding programs, is limited due to vegetative propagation used in the potato industry. Somaclonal variation provides a time-efficient tool to breeders for obtaining genetic variability, which is essential for breeding programs, at a reasonable cost and independent of sophisticated technology. The present investigation aimed to create potato somaclones with an improved potential for starch accumulation. Based on the weight and starch content of tubers, the somaclonal variant Ros 119, among 105 callus-sourced clones, recorded a higher tuberization potential than the parent cv Lady Rosetta in a field experiment. Although this somaclone was similar to the parent in the number of tubers produced, it exhibited tubers with 42 and 61% higher fresh and dry weights, respectively. Additionally, this clone recorded 10 and 75% increases in starch content based on the dry weight and average content per plant, respectively. The enhanced starch accumulation was associated with the upregulation of six starch-synthesis-related genes, namely, the AGPase, GBSS I, SBE I, SBE II, SS II and SS III genes. AGPase affords the glycosyl moieties required for the synthesis of amylose and amylopectin. GBSS is required for amylose elongation, while SBE I, SBE II, SS II and SS III are responsible for amylopectin. [ABSTRACT FROM AUTHOR]

Ginger (Zingiber officinale Rosc.) is an important spice crop valued for its flavored and medical properties. It is susceptible to soil-borne diseases, which can cause considerable economic loss to growers. In vitro culture is feasible for the propagation of disease-free ginger plants, but has several disadvantages when producing seed rhizomes that can be commercially used, such as long cultivation cycles (usually 2–3 years) and occurrence of somaclonal variation. In this study, dynamic changes in the morphological characteristics of in vitro-propagated disease-free plants of 'Wuling' ginger were evaluated by continuous observation and measurement at 30-day intervals, and morphological variants were screened and characterized by agronomic, cytological, and molecular analysis at harvest. Results showed that the plants grew rapidly within 120 days after planting, and the most active growth period was from 60 to 120 days. Eight plants with clear and stable morphological differences were screened out from approximately 2000 plants grown in the field, and they could be classified into two groups (VT1 and VT2) based on tiller number, plant height, leaf color, and leaf shape. By flow cytometry analysis and chromosome counting, the VT1 was confirmed to be diploid, with the shortest plant height, the largest number of tillers and rhizome knobs, and the smallest tiller diameter and rhizome size among the three types of plants. The VT2 was mixoploid, consisting of diploid and tetraploid cells, with significantly reduced tiller number and rhizome knobs, significantly larger stomatal guard cells/apertures, and significantly lower stomatal density. SSR analysis detected DNA band profile changes in six out of the eight variants, including one plant of the VT1 and all the VT2 plants. The findings of this study might contribute to the commercial production of disease-free seed rhizomes in ginger, and the characterized somaclonal variants could provide useful germplasm resources for future breeding. [ABSTRACT FROM AUTHOR]

Genetic assessment of pear regeneration population is very important for genetic fidelity maintenance in genetic engineering breeding. In this research, a regeneration system for a pear dwarfing rootstock cultivar, 'Qingzhen D1', was established using NN69 medium supplemented with different concentrations of thidiazuron (TDZ) and indole-3-butyric acid (IBA). The genetic stability of the regenerated population was evaluated through flow cytometry (FCM) and whole genome resequencing techniques. The highest regeneration rate (93%) was induced on NN69 medium supplemented with 3.0mg·L− 1 TDZ and 2.4mg·L− 1 IBA, with 3.9 adventitious buds per leaf. No phenotypes and ploidy changes were detected in regeneration population. But a high variation frequency (5.0 × 10 − 4) at a single site was detected. The mutations occurred most frequently on chromosome 5, 10 and 15, while least 4. High-impact changes only accounted for 0.065% of single-nucleotide polymorphism (SNPs) and 1.429% of insertions or deletions of nucleotides from a sequence (Indels) of all polymorphisms, most of which caused by frameshift. Functional analysis of genes affected by high-impact variants showed that they were mainly related to adaptation to environment. This study will provide a theoretical basis for the application of pear genetic engineering breeding in the future. [ABSTRACT FROM AUTHOR]

Plant tissue culture produces a wide range of genetic variations which are useful for quality improvement of the plant species. However, the differences in metabolic components and the key genes responsible for the difference in metabolic components between somaclonal variation and the original parent are still largely unknown. In this study, a mutant named 'Mixue' was identified with somaclonal variation of the 'Sachinoka' strawberry. The contents of pelargonidin-3-O-glucoside and cyanidin-3-O-glucoside in the red fruit of 'Mixue' were significantly decreased compared with 'Sachinoka'. In comparison with 'Sachinoka', the expression levels of FaMYB10, FaMYB11.2, FaWD40 and FaTT19 in the turning fruit of 'Mixue' were significantly down-regulated, while the expression of FaMYB1 was significantly up-regulated in the red fruit. 'Sachinoka' and 'Mixue' fruits were found to have 110 volatile components. Among them, 15 volatile components in the red fruit of 'Mixue' were significantly increased compared with 'Sachinoka', such as nerolidol, benzaldehyde, ethyl hexanoate, ethyl isovalerate, which led to an enhanced aroma in 'Mixue' and might result from the up-regulated expression of FaNES1, FaCNL and FaAATs in 'Mixue'. These results provide useful information on the effect of somaclonal variation on metabolic components of strawberry fruit and lay the foundation for the improvement in quality of strawberry. [ABSTRACT FROM AUTHOR]

Berry crops, a nutrient powerhouse for antioxidant properties, have long been enjoyed as a health-promoting delicious food. Significant progress has been achieved for the propagation of berry crops using tissue culture techniques. Although bioreactor micropropagation has been developed as a cost-effective propagation technology for berry crops, genetic stability can be a problem for commercial micropropagation that can be monitored at morphological, biochemical, and molecular levels. Somaclonal variations, both genetic and epigenetic, in tissue culture regenerants are influenced by different factors, such as donor genotype, explant type and origin, chimeral tissues, culture media type, concentration and combination of plant growth regulators, and culture conditions and period. Tissue culture regenerants in berry crops show increased vegetative growth, rhizome production, and berry yield, containing higher antioxidant activity in fruits and leaves that might be due to epigenetic variation. The present review provides an in-depth study on various aspects of phenotypic variation in micropropagated berry plants and the epigenetic effects on these variations along with the role of DNA methylation, to fill the existing gap in literature. [ABSTRACT FROM AUTHOR]

Gardenia jasminoides Ellis is an aromatic and medicinal plant of high economic value. Much research has focused on the phytochemistry and biological activities of Gardenia fruit extracts; however, the potential of the Gardenia plant in vitro cultures used as mass production systems of valuable secondary metabolites has been understudied. This paper presents data on metabolite profiling (GC/MS and HPLC), antioxidant activities (DPPH, TEAC, FRAP, and CUPRAC), and SSR profiles of G. jasminoides plant leaves and in vitro cultures with different levels of differentiation (shoots, callus, and cell suspension). The data show strong correlations (r = 0.9777 to r = 0.9908) between antioxidant activity and the concentrations of chlorogenic acid, salicylic acid, rutin, and hesperidin. Eleven co-dominant microsatellite simple sequence repeats (SSRs) markers were used to evaluate genetic variations (average PIC = 0.738 ± 0.153). All of the investigated Gardenia in vitro cultures showed high genetic variabilities (average Na = 5.636 ± 2.157, average Ne = 3.0 ± 1.095). This is the first report on a study on metabolite profiles, antioxidant activities, and genetic variations of G. jasminoides in vitro cultures with different levels of differentiation. [ABSTRACT FROM AUTHOR]

In vitro plant regeneration is a pivotal process in genetic engineering to obtain large numbers of transgenic, cisgenic and gene edited plants in the frame of functional gene or genetic improvement studies. However, several issues emerge as regeneration is not universally possible across the plant kingdom and many variables must be considered. In grapevine (Vitis spp.), as in other woody and fruit tree species, the regeneration process is impaired by a recalcitrance that depends on numerous factors such as genotype and explant-dependent responses. This is one of the major obstacles in developing gene editing approaches and functional genome studies in grapevine and it is therefore crucial to understand how to achieve efficient regeneration across different genotypes. Further issues that emerge in regeneration need to be addressed, such as somaclonal mutations which do not allow the regeneration of individuals identical to the original mother plant, an essential factor for commercial use of the improved grapevines obtained through the New Breeding Techniques. Over the years, the evolution of protocols to achieve plant regeneration has relied mainly on optimizing protocols for genotypes of interest whilst nowadays with new genomic data available there is an emerging opportunity to have a clearer picture of its molecular regulation. The goal of this review is to discuss the latest information available about different aspects of grapevine in vitro regeneration, to address the main factors that can impair the efficiency of the plant regeneration process and cause post-regeneration problems and to propose strategies for investigating and solving them. • In vitro plant regeneration is a pivotal process for New Breeding Techniques. • In grapevine the regeneration process is impaired by recalcitrance related to genotype. • 'Molecular keys' to unlock the regeneration overall grapevine cultivars are suggested. • Approaches to study and achieve grapevine regeneration more efficiently are proposed. [ABSTRACT FROM AUTHOR]

Simple Summary: Cryopreservation technology has been developed, demonstrating safe, efficient, and economic benefits for the long-term preservation of genetic resources. It receives more attention because dramatic germplasm losses have been observed in field conservation, caused by many factors such as climate change, natural hazards, and diseases. Therefore, demands for cryobanking crops have been increasing. Cryopreservation methods have been developed for strawberries, the most preferred berry fruit, due to their nutritional and economic values. However, during the cryopreservation process, the explants are exposed to many steps under stressful conditions, which may induce somaclonal variations. The article describes a genetic stability assessment by the greenhouse performance of vegetative and fruit traits and molecular marker analysis for six strawberry accessions. Our results suggest that the cryopreservation protocol used in this study can be applied to implement cryobanking of strawberry germplasm. For the long-term preservation of genetic resources, cryopreservation techniques have been developed for strawberry germplasm, mainly using in vitro-grown shoot tips. In this study, genetic stability was tested under greenhouse conditions for six strawberry accessions (IT232511, PHS0132, IT245810, IT245830, IT245852, and IT245860) derived from the following procedures: (1) conventional propagation (GH: greenhouse maintained); (2) in vitro propagation (TC: tissue culture); (3) pretreatment before cryopreservation (−LN: non-liquid nitrogen exposure); and (4) cryopreservation (+LN: liquid nitrogen exposure). To test the performance of phenotypic traits, we measured six vegetative and five fruit traits. There were no distinct differences in most of the characteristics, but a few traits, such as sugar content and pH of fruits in three accessions, showed higher values in +LN compared to GH. However, the differences disappeared in the first runner generation. To test genetic variations, a total of 102 bands were generated by twelve inter simple sequence repeat (ISSR) primers. A few polymorphic bands were found only in plants derived from TC of IT245860, which was not cryopreserved. The sequencing analysis of four polymorphic bands produced by ISSR_15 showed that none of these sequences matched the characterized genes in NCBI. Phenotypic abnormality was not observed across all plants. This study indicates that cryopreserved plants of the six strawberry accessions are phenotypically and genetically stable. Therefore, the results of this study can help to implement cryobanking of strawberry germplasm. [ABSTRACT FROM AUTHOR]

Berry crops, a nutrient powerhouse for antioxidant properties, have long been enjoyed as a health-promoting delicious food. Significant progress has been achieved for the propagation of berry crops using tissue culture techniques. Although bioreactor micropropagation has been developed as a cost-effective propagation technology for berry crops, genetic stability can be a problem for commercial micropropagation that can be monitored at morphological, biochemical, and molecular levels. Somaclonal variations, both genetic and epigenetic, in tissue culture regenerants are influenced by different factors, such as donor genotype, explant type and origin, chimeral tissues, culture media type, concentration and combination of plant growth regulators, and culture conditions and period. Tissue culture regenerants in berry crops show increased vegetative growth, rhizome production, and berry yield, containing higher antioxidant activity in fruits and leaves that might be due to epigenetic variation. The present review provides an in-depth study on various aspects of phenotypic variation in micropropagated berry plants and the epigenetic effects on these variations along with the role of DNA methylation, to fill the existing gap in literature.