Search Results (9)

Hyperhydricity is a significant challenge in the tissue culture of blueberry plantlets, affecting their propagation, survival and quality, which results in economic losses for industrial blueberry micropropagation. The in vitro liquid propagation of two half-highbush blueberry hybrids, HB₁ and HB₂, showed that a Growtek stationary bioreactor culture system containing a liquid medium exhibited a higher hyperhydricity percentage than a Sigma glass culture system with a semi-solid medium. The percentage of hyperhydricity (75.21 ± 1.89%) and water content (72%) of HB₂ was more than that of HB₁. A scanning electron microscopy study revealed that hyperhydric plantlets from both genotypes developed slowly, had closed stomata, and displayed enlarged intercellular spaces between the palisade and spongy parenchyma layers. Disrupted vascular bundles, underdeveloped sieve elements and a weak connection between phloem and xylem tissue were also observed in hyperhydric plantlets. An analysis of mesophyll and stem tissues highlighted a compressed adaxial epidermis, which led to compact palisade parenchyma, with irregularly shaped mesophyll cells. Hyperhydric plants showed strong nuclear magnetic resonance (NMR) signals in the aliphatic, aromatic, and sugar regions, specifically at peaks of 2.0, 2.5, 4.0, 4.5, 6.0, and 6.7 ppm. These signals were attributed to the presence of catechin (C₁₅H₁₄O₆), a flavonoid compound, suggesting its significant role or accumulation in these plants under hyperhydric conditions. Despite the negative effects of hyperhydricity on commercial propagation, hyperhydric plants were found to contain higher levels of valuable untargeted metabolites, such as β-P-arbutin, chlorogenic acid, quercetin-3-O-glucoside, epicatechin, 2-O-caffeoyl arbutin, various fatty acids, β-glucose, linolenic acid, and acetyl than both in vitro and ex vitro conditions. The enrichment of bioactive compounds in blueberry enhances its antioxidant properties, nutritional profile, and potential health benefits, making them significant for plant defense mechanisms and stress adaptation. Full article

Conventional in vitro propagation using semisolid Murashige and Skoog (MS) culture systems is costly, labor-intensive, and requires substantial space for large-scale plant production. This study investigated the application of a temporary immersion bioreactor (TIB) system for the micropropagation of the banana cultivar Kluai Numwa Pakchong 50, as a promising platform for economical commercial production. The cultivation parameters affecting plantlet multiplication, including plant growth regulator (PGR) use, explant density, and immersion frequency, were examined. Additionally, the ex vitro acclimatization of well-developed in vitro plantlets was also evaluated. Using liquid MS medium supplemented with 7.5 mg/L 6-benzylaminopurine (BAP) in the TIB system yielded significantly better results than the conventional semisolid MS control system, producing more shoots (5.60 shoots/explant) and leaves (2.80 leaves/explant) with longer shoot length (2.19 cm). Optimal conditions in the TIB system included an inoculum density of five explants per culture vessel and an immersion frequency of once every 6 or 8 h for 2 min. For root induction, 0.5 mg/L indole-3-butyric acid (IBA) proved more effective than 1-naphthaleneacetic acid (NAA). After 30 days of ex vitro acclimatization, plantlets regenerated from the TIB system demonstrated high survival rates, vegetative growth performance, and root formation efficiency comparable to those from the semisolid culture system. These findings establish the TIB system as a promising platform for the mass propagation of the Kluai Numwa Pakchong 50 banana. The protocol developed in this study could potentially be adapted for large-scale production of other banana varieties. Full article

Aseptic seedlings of different ages derived from surface-sterilized mature seeds were applied as an explant source. Various explants such as 7- and 21-day-old hypocotyl fragments, 42-day-old nodal stem segments, and transverse nodal segments of stem, as well as leaf petioles, were cultured on the agar-solidified Murashige and Skoog (MS) basal medium supplemented with 0.1 mg/L IAA, 5 mg/L AgNO₃ and different types and concentrations of cytokinin (1 mg/L zeatin, 0.25 mg/L thidiazuron (TDZ), and 5 mg/L 6-benzylaminopurine (6-BAP)). Consequently, it was found that 7- and 21-day-old hypocotyl fragments, as well as nodal stem segments obtained from adult aseptic seedlings, are characterized by a high explant viability and callus formation capacity with a frequency of 79.7–100%. However, the success of in vitro somatic shoot organogenesis was significantly determined not only by the culture medium composition and explant type but also depending on its age, as well as on the size and explant preparation in cases of hypocotyl and age-matched nodal stem fragments, respectively. Multiple somatic shoot organogenesis (5.7 regenerants per explant) with a frequency of 67.5% was achieved during 3 subcultures of juvenile hypocotyl-derived callus tissue on MS culture medium containing 0.25 mg/L TDZ as cytokinin source. Castor bean regenerants were excised from the callus and successfully rooted on ½ MS basal medium without exogenous auxin (81%). In vitro plantlets with well-developed roots were adapted to ex vitro conditions with a frequency of 90%. Full article

Gujarat is one of India’s top potato-producing regions, making it one of the world’s top producers of potatoes. The demand for potatoes is driven by the food processing industry, domestic consumption, and export opportunities. While potato production in India has been growing, there are several issues that affect the industry. The availability of high-quality potato seeds, as well as post-harvest losses due to improper handling and storage, are major challenges. The purpose of this study was to investigate the effects of various culture systems and nutrient supplements to establish and optimize a suitable system for in vitro shoot growth, microtuberization, and storage conditions. In vitro cultures of six different locally adapted potato cultivars were created and the shoot multiplication protocol was standardized. The microtubers protocol was optimized using four-week-old shoots, and a mean of four microtubers per shoot was observed on the Murashige and Skoog medium supplemented with 6-benzylaminopurine (0.88 µM) and sucrose (8%). Harvested microtubers were used to investigate storage conditions and shoot growth was evaluated from microtubers under in vitro as well as ex vitro conditions. All microtubers developed healthy shoots after 18 days of storage at 4 °C both in vitro and ex vitro, and the resulting plantlets showed >90% survival in the greenhouse. The distribution of high-quality potato seeds in Gujarat, which are in high demand, may benefit from the optimal microtubarization protocol. This study confirms the potential of long-term germplasm preservation and microtuber-based cultivation practices in the Gujarat. Full article

The endangered medicinal plant Eryngium maritimum L. faces significant natural and anthropogenic threats. Therefore, in vitro propagation is recommended for both conservation and commercial purposes. The aim of the study was to develop a series of protocols for seed disinfection, in vitro multiplication and rooting, and ex vitro and field adaptation. For explant disinfection, the length and temperature of three consecutive disinfectants were investigated. Macrosalt modifications of MS medium and plant growth regulator addition to media effect on axillary bud propagation rate and rooting was studied. Survival and leaf growth during ex vitro and field adaptation in response to potting media, pot cell diameter, and light spectrum were tested. Seeds treated with diluted detergent at 40 °C for 180 min, followed by 0.01% KMnO₄ for 3 h and commercial bleach for 11 min, achieved a lower rate of contamination and high germination rate. Axillary bud proliferation and rooting were enhanced by reducing nitrogen content in media and adding plant growth regulators. Potting media and pot size affect survival and growth ex vitro. Timely transplantation to field conditions before overwintering increases plantlet survival. In the present work, a suitable foundation is laid to scaleup the production of E. maritimum by micropropagation. Full article

Black cardamom (Amomum tsao-ko Crevost & Lemarié) is a spice plant of great commercial value in Vietnam, but with limited propagation ability. Its seeds are characterized by a thick and hard seed coat, a small endosperm, and a small embryo, which are the causes of the physical dormancy of the seeds and low germination. Attempts in this study to improve the germination rate and achieve uniform germination included mechanical scarification, immersion in hot or cold water, acid scarification, and the application of plant growth regulators. Although immersion of seeds in cold water and application of plant growth regulators (PGRs) (gibberellic acid (GA₃) and 1-naphtaleneacetic acid (NAA)) showed positive effects on seed germination and subsequent seedling growth, mechanical scarification provided the highest germination rate of black cardamom seeds (68.0%) and significantly shortened germination time (53.7 days) compared to control (16.0% and 74.7 days). On the other hand, an efficient micropropagation protocol has been established using shoot tip explants derived from in-vitro-grown seedlings. Murashige and Skoog (MS) medium supplemented with 4.0 mg/L 6-benzylaminopurine (BAP) + 0.5 mg/L NAA proved to be most suitable for rapid multiplication and rooting, providing a mean of 5.4 shoots per explant, 6.8 cm shoot length, and 16.2 roots per explant after 7 weeks of culture. Well-rooted black cardamom plantlets have been successfully adapted to ex vitro conditions. “Fasco” bio-soil was more suitable for acclimatization, with a 48.9% survival rate, 23.3 cm plant length, and 5.7 leaves per plant after 3 months of planting. Improved germination and multiplication protocols can be used to improve propagation performances and to develop elite of black cardamom planting material. Full article

Plants propagated by seed do not ensure genetic uniformity and are sometimes infected with diseases. In Vitro micropropagation techniques are an alternative method to traditional cloning approaches for producing true-to-type and pathogen-free plants. However, due to the particularities of the in vitro environment, these plants face many challenges, often critical to their survival, to adapt to ex vitro conditions. In this context, four substrates and two types of mineral nutrition (quick-release (QRF) and controlled-release (CRF) fertilizers), as well as their absence were evaluated in the process of acclimatization of Solanum betaceum plants. Stomatal conductance (g_s), chlorophyll content index (CCI), and dry biomass of roots, shoots, and entire plants were the parameters analyzed during the acclimatization. The best crop performance (g_s, CCI, and dry biomass) were observed in substrates consisting of vermiculite plus the application of mineral nutrients through a CRF, proving that mineral nutrition has the greatest positive impact on the acclimatization process. In these conditions, plants were obtained with a total dry biomass being significantly higher (515.0 mg (QRF) and 635.9 mg (CRF) when compared to the total dry biomass of untreated plants (119.9 mg). The best conditions for this first experiment were replicated in a second test in order to assess the best fertilizer amount suited for plantlet growth. In this case, the best results were obtained with 0.4 g of CRF, in which plants showed a dry biomass of roots (542.7 mg) and a total dry biomass (594.5 mg), which was significantly higher than in the control (183.2 mg and 165.9 mg, respectively) or with other concentrations of CRF (0.8 and 1.6 g). A similar trend was found concerning the CCI (5.3) and g_s (72.5 mmol m⁻² s⁻¹) in which 0.4 g CRF gave also the best results when compared with the control (without CRF) or with 0.8 g (4.7 and 56.2 mmol m⁻² s⁻¹) and 1.6 g (4.7 and 52.2 mmol m⁻² s⁻¹) treatments. In general, it was found that tamarillo plantlets acclimatized to 0.4 g of CRF had a faster initial growth and better performance (CCI and g_s), with plants ready to go to the greenhouse/field more quickly, thus reducing the time to obtain suitable plants for the market and shortening the production cycle. Full article

Eremurus spectabilis M. Bieb, a perennial herbaceous wild species, is commonly used in the horticultural, ornamental, and pharmaceutical markets. Studies on the tissue culture systems for this species would be beneficial for mass multiplication as well as for future breeding programs. An in vitro propagation technique was established here using tuberous root explants as unique and responsive starting materials for culture initiation. The proliferated calli were sub-cultured on shoot proliferation media and regenerated microshoots were assessed. The shoot proliferation rate, leaf number, leaf length, and chlorophyll and carotenoid contents were recorded. The highest callus induction per explant (76.67%), callus dry weight (10.25 mg), callus firmness ratio (3.97), and callus color intensity ratio (2.83) were observed in explants inoculated on Murashige and Skoog (MS) medium supplemented with 10.0 mgL⁻¹ 6-benzylaminopurine (BAP). The highest shoot proliferation rates were obtained when calli were sub-cultured on MS or Schenk and Hildebrandt (SH) basal media supplemented with 2.0 mgL⁻¹ BAP. The half-strength MS medium fortified with 4.0% sucrose + 2.0 mgL⁻¹ indole butyric acid (IBA) + 200 mgL⁻¹ activated charcoal was a superior combination for root emergence and rooting parameters. Regenerated plantlets were then successfully adapted to ex vitro conditions. The reported protocol can be exploited at a commercial scale following minor modification, or could be beneficial in the production of secondary metabolites in bioreactors where callus is required as fresh plant material. Full article

Pseudostellaria heterophylla, in the family Caryophyllaceae, is an important Chinese medicinal plant commonly used to treat various diseases in children and valued for its ornamental properties. In this study, nodal segments were obtained from wild plants and used as explants to develop an efficient micropropagation protocol for this species. Murashige and Skoog (MS) medium supplemented with 1.5 mg·L⁻¹ 6-benzyladenine (6-BA) was the most suitable medium for inducing axillary buds and enhancing their growth, and MS medium containing 0.1 mg·L⁻¹ indole-3-butyric acid (IBA) was the most effective for inducing in vitro rooting. To reduce labor, time, and cost, microshoots were rooted under ex vitro conditions. Pretreatments of the shoots with 100 mg·L⁻¹ naphthaleneacetic acid (NAA) for 1 min ensured successful rooting in 86.7% of shoots. Comparison of the leaf microstructure between in vitro- and ex vitro-rooted plantlets revealed abnormal stomatal apparatus in the former. The stomatal apparatus of ex vitro plantlets were normal, although the stomatal density was reduced, which indicated that these plantlets were more likely to be able to adapt to environmental conditions in the field. We identified the optimal medium for P. heterophylla multiplication with respect to increased rooting efficiency of micropropagated shoots under ex vitro conditions. This results presented here will be helpful for agricultural cultivation of P. heterophylla. Full article