Search Results (222)

Plant growth regulators of natural origin are becoming increasingly important in crop production to protect plants against various abiotic stresses and often to modulate plant pathological processes. These compounds offer the potential to enhance plant health exogenously by protecting plants against oxidative stress. Melatonin has been studied previously; however, the role of exogenous melatonin in abiotic stress tolerance and the underlying mechanisms are still less understood. In this study, potato plants were grown in vitro to study the effects of exogenous melatonin and ultrasound treatment (latter as an abiotic stress). The measured parameters included morphological data and the concentrations of melatonin and its degradation products, indole-3-acetic acid and salicylic acid, at 0 h, 24 h, 1 week, and 4 weeks after treatment. In addition, the expression levels of the genes responsible for the production of enzymes involved in melatonin synthesis were traced by RT-qPCR analysis. Melatonin added to the culture medium was taken up by the in vitro plantlets, and it participated both in the plant stress reaction and stress mitigation when an abiotic stress reaction was triggered by ultrasound. Among the degradation products, we detected N-acetyl-5-methoxykynuramine, 6-hydroxymelatonin, and 5-methoxytryptamine by UHPLC-MS. Among the enzymes involved in the synthesis of melatonin and indole-3-acetic acid, the expression levels of COMT, SNAT, TSB, TAA, ASMT, TPH, AANAT, ASMT, and TSA were measured and no pattern was observed in response to the treatments. Full article

Arbuscular mycorrhizal fungi (AMF) play a key role in enhancing plant stress tolerance, nutrient uptake, and overall health, making them essential for sustainable agriculture. Their multifaceted contributions to the rhizosphere—through biofertilization, bioprotection, and biostimulation—have led to growing interest in their application. In recent years, in vitro mycorrhization has emerged as a promising approach for the rapid propagation of economically and ecologically important plant species, offering improved agronomic and physiological traits as well as increased resilience to environmental stressors. However, challenges remain in achieving consistent AMF-plant symbiosis under in vitro conditions across diverse species. This review highlights the potential of in vitro mycorrhization as a controlled system for investigating AMF interactions and their impact on plant development. Various in vitro mycorrhization systems are described and discussed, along with their applications in the mass production of AMF propagules and mycorrhizal plants, and their role in enhancing the acclimatization of micropropagated plantlets to ex vitro conditions. The role of in vitro mycorrhization as an effective tissue culture approach that integrates plant propagation with enhanced resilience to environmental stress is emphasized. The factors influencing the success of in vitro mycorrhization and strategies for the large-scale production of AMF propagules and mycorrhizal plants are explored. Although research in this area is still limited, existing studies underscore the potential of in vitro mycorrhization to enhance plant tolerance to abiotic and biotic stresses—an increasingly urgent goal in the context of climate change and global food security. Full article

Longshan Lilium lancifolium is a well-known medicinal and edible lily and has been registered as a geographical indicator in China. Polyploidization confers many advantages in lily production; however, characteristics of Longshan L. lancifolium improved by polyploidization have not been reported. Here, polyploidization was induced in regenerated Longshan L. lancifolium shoots using colchicine, and the mutant plantlets were characterized by morphological observation, flow cytometry, and inter simple sequence repeat (ISSR) marker technology. The optimal medium for inducing shoot regeneration was Murashige and Skoog (MS) media supplemented with 0.2 mg/L of naphthaleneacetic acid (NAA) and 0.4 mg/L of thidiazuron (TDZ). The greatest mutation induction effect was obtained after soaking the regenerated shoots in 0.10% colchicine for 48 h, for an 80.00% frequency of morphological variants. Forty-one mutant plantlets were subjected to flow cytometry, identifying one homozygous polyploid, ‘JD-12’, and one chimeric polyploid, ‘JD-37’. Additionally, 68 chromosomes were found in the ‘JD-12’ root tip cells. Compared with the control, both the tissue-cultured and field-generated ‘JD-12’ plantlets presented a slight decrease in plant height, a darker green leaf color, a rougher leaf surface, and a larger bulblet diameter; furthermore, the upper epidermal and guard cells of ‘JD-12’ were much larger with a significantly lower stomatal density. The ISSR marker detection indicated a genetic variation rate of 6.10% in ‘JD-12’. These results provide a basis for lily polyploidization breeding and the cultivation of superior Longshan L. lancifolium via shoot regeneration. Full article

Zinc oxide nanoparticles (ZnONPs) are increasingly used in agriculture to stimulate plant growth and development, including under in vitro culture conditions. However, there is limited data on the effects of ZnONPs on the micropropagation of Scutellaria baicalensis Georgi. The pharmacological properties of this species make it a valuable medicinal plant. In Poland, it does not occur naturally but is cultivated for the production of herbal material. In vitro micropropagation is an effective method for obtaining genetically uniform plantlets. The aim of this study was to evaluate the effects of various concentrations of ZnONPs on growth parameters and the content of mineral nutrients, phenolic compounds, antioxidants, and photosynthetic pigments in Scutellaria baicalensis cultured in vitro. Shoot tip explants were cultured on MS medium supplemented with 1.0 mg dm⁻³ BA and 0.1 mg dm⁻³ IBA, together with ZnONPs at concentrations of 0 (control), 10, 20, 30, and 40 mg dm⁻³. The results showed that ZnONPs at concentrations of 10–20 mg dm⁻³ had no statistically significant effect on shoot or root development or on fresh weight gain. However, higher concentrations (30 and 40 mg dm⁻³) had a significantly negative impact on the number and length of shoots and roots, as well as on biomass accumulation. ZnONPs at 10–20 mg dm⁻³ significantly increased the content of potassium, calcium, magnesium, iron, and zinc in regenerated multi-shoot plantlets. A strong positive correlation (r = 0.951) was observed between ZnONP concentration and zinc accumulation in the plantlets. The levels of manganese and copper were not significantly different from the control. Plantlets treated with 30–40 mg dm⁻³ ZnONPs had significantly lower levels of calcium, iron, manganese, and copper. Those grown at 30 mg dm⁻³ had the highest potassium and magnesium levels, while plantlets exposed to 40 mg dm⁻³ had the highest zinc content. The total phenolic content and antioxidant activity (measured using ABTS and DPPH assays) were significantly higher in ZnONP-treated plantlets compared to the control. In contrast, the levels of chlorophyll a, chlorophyll b, total chlorophyll (a + b), and carotenoids were significantly lower in plants treated with ZnONPs. A strong negative correlation was found between ZnONP concentration and photosynthetic pigment content, while the ZnONP concentration was positively correlated with total phenolic content and antioxidant activity (ABTS⁺ and DPPH). Full article

The introduction of new ornamental species and cultivars is one of the hallmarks of innovation in global floriculture. Brunfelsia uniflora, a subshrub native to Brazil, has white, lilac, and blue flowers on the same plant, in addition to a distinctive fragrance. As it is a wild species, technologies such as large-scale clonal propagation of superior genotypes are still scarce, limiting its supply to the flower market. Therefore, a successful micropropagation protocol was developed for B. uniflora using nodal segments and shoot tips as initial explants. In the multiplication phase, the use of 6-benzylaminopurine produced the highest multiplication rates (10.3–10.9 shoots/explant) and the number of leaves in the shoots. In vitro shoot rooting using MS medium with reduced macronutrient concentrations and supplemented with IBA resulted in a 91.7% rooting rate. The greatest difficulty in micropropagating this species was the high percentage of shoots that developed calli. The highest percentage of callus formation occurred with the addition of auxins at high concentrations (1.0 and 1.5 mg L⁻¹). Even so, the shoots and plantlets were acclimatized, demonstrating the effectiveness of this technique for the production of B. uniflora plantlets. Full article

The production of healthy propagating material of the potato (Solanum tuberosum L.) is based on in vitro micropropagation. In vitro conditions, however, can cause stress leading to reduced quality, growth and development of in vitro plantlets. The effects of aeration and chemical additives on the in vitro growth and development and quality of potato plantlets were investigated. Four different jar closure types were tested, i.e., an intact metal cap (control), two layers of semi-permeable plastic foil, a metal cap with a single hole, or a metal cap with three holes. Under tightly sealed conditions (intact metal cap) the effects of silver nitrate (2.0 mg L⁻¹) and 1-naphtylacetic acid (0.1 mg L⁻¹) alone or in combination with each other, meta-topoline (0.1 mg L⁻¹), ascorbic acid (10.0 mg L⁻¹), salicylic acid (0.1 mg L⁻¹), jasmonic acid (0.1 mg L⁻¹) and glutamic acid (0.3 mg L⁻¹) were studied. Morpho-physiological parameters were measured at the end of the subculture. Leaf development was a good indicator of the presumed ethylene effect. The development and quality of the plantlets were best in cultures sealed with three-holed caps. Of the chemicals applied, only the presence of silver nitrate resulted in high-quality plantlets. The combined application of silver nitrate and 1-naphthaleneacetic acid promoted root growth and development. Full article

Turmeric (Curcuma longa L. cv. Trang 1), a high-value cultivar known for its elevated curcuminoid and volatile oil content, holds significant potential in pharmaceutical and food applications. However, its commercial propagation is constrained by low rhizome productivity and the limitations of conventional vegetative propagation. This study aimed to improve the propagation efficiency of turmeric cv. Trang 1 by developing optimized protocols for explant sterilization, shoot proliferation, root induction, and acclimatization. Sprouted rhizome buds were sterilized and cultured on a Murashige and Skoog (MS) medium supplemented with various plant growth regulators, including cytokinins (benzyladenine [BA], thidiazuron [TDZ], and meta-topolin [mT]) and auxins (indole-3-butyric acid [IBA] and 1-naphthaleneacetic acid [NAA]). The shoot induction (4.60 ± 1.47 shoots per explant) and shoot height (2.34 ± 0.61 cm) were observed on the MS medium with 3.0 mg/L BA, while the TDZ, at 0.5 mg/L, also induced a high number of shoots (5.22 ± 0.64). When using single shoots derived from bud explants, mT at 1.5 mg/L significantly enhanced the shoot formation. For the root induction, 2.0 mg/L IBA yielded the highest number of roots (7.33 ± 1.49), while NAA was less effective. The plantlets acclimatized in a 1:1 soil and peat moss mixture showed the highest survival rate (86.67%). This improved protocol enables the efficient production of turmeric plantlets, supporting commercial deployment. Full article

Philodendron ‘White Knight’ is a popular climbing evergreen plant typically propagated through stem cuttings. However, this method is slow and inefficient, making it challenging to meet the rising market demand. In vitro propagation could enhance the multiplication of this cultivar. However, research on its in vitro propagation is limited. Therefore, the objective of the present study was to establish an efficient micropropagation technique to mass-produce Philodendron ‘White Knight’ to meet the market demand. We investigate the impact of silver nanoparticles (Ag NPs) on the surface sterilization of Philodendron ‘White Knight’ petioles, the role of plant growth regulators in adventitious shoot regeneration and shoot multiplication, and the effect of auxins on the rooting ability of Philodendron ‘White Knight’ microshoots. There are few stages in plant micropropagation. The establishment of aseptic culture is the first and most important stage. For Philodendron ‘White Knight’, aseptic petiole explants (100%) were obtained after treatment with 40 mg L⁻¹ Ag NPs for 60 min. This was followed by adventitious shoot induction, and the highest rate of adventitious shoot induction (52.6%) and the maximum shoot number (13.9 shoots per petiole) were achieved on Murashige and Skoog shoot multiplication B (MS-B) medium with 20 µM of 2-isopentenyl adenine (2-IP) and 5.0 µM of naphthalene acetic acid (NAA). The shoot multiplication stage was achieved with the highest number of shoots (34 shoots per shoot tip) with a length of 5.1 cm, which was obtained on MS-B medium with 5.0 µM 2-IP and 2.5 µM NAA. All the microshoots produced roots during the root induction stage with the maximum root number (8.2 roots per shoot), and the greatest plantlet height (9.1 cm) was achieved on half-strength Murashige and Skoog medium containing indole-3-butyric acid (10.0 μM). The rooted plantlets of Philodendron ‘White Knight’ were transplanted into a substrate composed of 10% peat moss, 50% orchid stone, and 40% coconut husk chips and acclimatized in a greenhouse environment, achieving a survival rate of 100%. This micropropagation protocol can be used for the commercial production of Philodendron ‘White Knight’. Full article

Lobelia chinensis (Lour.) is a medicinal plant that contains phytochemicals, such as phenolics and polyacetylene compounds, with beneficial biological activities. In vitro cultures are typically employed for biomass generation and plant multiplication. However, the current biotechnological approaches for producing these chemicals are ineffective, which is why bioelicitors are being used to boost synthesis of these molecules. Plantlet cultures were established in vitro using Murashige and Skoog medium supplemented with 3% sucrose (w/v). Following 4 weeks of culture initiation, the plantlet cultures were treated with 0, 25, 50, 100, or 200 mg L⁻¹ of yeast extract (YE) or with 0, 25, 50, 100, or 200 µM of salicylic acid (SA) for 1 week to boost the synthesis of bioactive compounds. The amounts of total phenolics, total flavonoids, specific phenolics including catechin, phloretic acid, linarin, and polyacetylenes, including lobetyolinin and lobetylin, were considerably elevated in the plantlet cultures treated with 50 mg L⁻¹ YE and/or 25 µM SA. The 2,2 Diphenyl 1 picrylhydrazyl (DPPH) radical scavenging assay, 2,2′-azino-bis (3-ethybenzothiazoline-6-sulphonic acid) (ABTS) assay, and ferric reducing antioxidant power (FRAP) assay were performed to assess the antioxidant properties of the plantlets. The elicitor-treated plantlets were found to have higher antioxidant activity. Thus, plantlet biomass produced in vitro can be used as a raw material to produce medicinal and nutraceutical products. Full article

Pinus massoniana Lamb. (masson pine) is a critical species for afforestation in southern China but faces severe threats from pine wilt disease (PWD) caused by Bursaphelenchus xylophilus. To accelerate disease-resistant breeding, this study investigated the effects of cryopreservation on the embryonic capacity of the embryogenic callus as well as the effects of abscisic acid (ABA), polyethylene glycol 8000 (PEG 8000) and phytagel concentration on the somatic embryo’s maturation and germination. Furthermore, the impact of transplanting substrates on the survival and growth of regenerated plantlets were evaluated. The results showed that cryopreservation at −196 °C effectively maintained the embryogenic potential of the callus, with post-thaw tissues exhibiting superior somatic embryo maturation capacity compared to the long-term subcultured callus (38.4 vs. 13.2 embryos/mL). Key maturation parameters were systematically optimized: ABA concentration at 6 mg/L in the suspension culture maximized embryo yield of 24.1 somatic embryos/mL, while PEG 8000 at 130 g/L in solid medium achieved peak embryo production of 38.4 somatic embryos/mL, and the maximum of 26.6 somatic embryos/mL when the concentration of phytagel was 3.5 g/L. The highest germination rate of 29.8% was observed with 130 g/L PEG in the maturation medium. The highest survival rate (56.5%) and maximum plant height (22.3 cm) after 12 months of transplantation were achieved in substrates consisting of soil and vermiculite, which outperformed those containing varying proportions of mushroom residue. This study establishes a scalable protocol for the mass propagation of PWD-resistant P. massoniana, integrating cryopreservation and maturation media optimization, which offers dual benefits for disease-resistant breeding and sustainable germplasm conservation. Full article

In this study, a reliable and efficient micropropagation protocol was developed for Stachys byzantina, a valuable and promising ornamental species. For the initial in vitro cultures on the Murashige and Skoog (MS) medium, shoot tips were used as explants. The addition of 5 μM of kinetin (KIN) resulted in the production of multiple (6.0 shoots/explant) and elongated (3.6 cm) shoots. The MS medium supplemented with 10 μM of a-Naphthaleneacetic acid (NAA) proved efficient for the in vitro rooting (73.3%) of the microshoots. For the ex vitro rooting of the microshoots, the treatment with 0.5 g L⁻¹ of Indole-3-butyric acid potassium salt (K-IBA), before planting in 1:1 (v/v) peat and perlite substrate and placed in a fog system, led to 86.7% rooting. The acclimatization stage was successful, and 96.7% survival was recorded for the ex vitro-rooted plantlets. Inter Simple Sequence Repeat (ISSR) markers were employed to examine the genetic uniformity of the in vitro-derived plantlets with the mother S. byzantina plants. The monomorphic banding pattern in the micropropagated plants and the mother plant confirmed the genetic uniformity of the in vitro-derived plantlets and revealed the reliability of the proposed in vitro protocol for S. byzantina. As far as we know, this is the first study on a combined micropropagation and genetic uniformity assessment of the species, the findings of which could be further used to apply new in vitro cultivation techniques or to produce elite genotypes of S. byzantina. Full article

The production of carrot (D. carota L.) doubled haploids (DH) for the acceleration of this important vegetable crop breeding requires genome doubling of haploid regenerants. If spontaneous doubling does not occur, artificial chromosome doubling can be complicated by the lack of efficient genome-doubling protocols. We tested an antimitotic agent treatment of carrot at the embryo stage. It allowed us to produce and treat a large number of clonal carrot embryos (at least 30 embryos per treatment condition) in small volumes with minimal reagent amounts. We showed that 0.01–1 g/L colchicine did not perturb carrot development. Trifluralin showed no signs of toxicity at 0.001 and 0.01 g/L concentrations, but 0.1 g/L trifluralin reduced survival by 40% and delayed plantlet regeneration. We showed via DNA content flow cytometry that 0.01–1 g/L colchicine and 0.001–0.1 g/L trifluralin could double the carrot genome. The highest diploid percent was observed at 1 g/L colchicine (34%) and 0.1 g/L trifluralin (28%). The highest percent of diploids together with mixoploids (partial diploids) was at 0.01 and 0.1 g/L trifluralin (over 70%), followed by 1 g/L colchicine (56%). To our knowledge, this is the first report on trifluralin application for genome doubling in Apiaceae. In our study, we determined colchicine and trifluralin toxicity and doubling efficiency at different concentrations that can be used for carrot DH-line production and further improvement of genome doubling methods. Full article

Spent mushroom substrate (SMS), a waste product from mushroom cultivation, in addition to being rich in essential nutrients for crop growth, contains actively growing mushroom mycelia and metabolites that suppress some plant pathogens and pests. SMS thus has potential for fostering the suppressiveness of soil-borne pathogens of farms. This study determined the potential of using the spent Pleurotus ostreatus substrate (SPoS) to suppress the plant-parasitic nematode Radopholus similis in bananas. R. similis is the most economically important nematode in bananas worldwide. The effect of SPoS on R. similis was assessed through two in vivo (potted plants) experiments between May 2023 and June 2024. Five-month-old East African highland banana (genome AAA) plantlets that are highly susceptible to R. similis were used. In the first experiment, the plantlets were established in 3 L pots containing (i) pre-sterilized soil, (ii) pre-sterilized soil inoculated with nematodes, (iii) pre-sterilized soil mixed with 30% (v/v) SPoS, (iv) pre-sterilized soil mixed with 30% (v/v) SPoS followed by nematode inoculation, (v) SPoS without soil, and (vi) SPoS without soil inoculated with nematodes. The SPoS was already decomposed; thus, it may or may not have contained active mycelia. The nematodes were introduced two weeks after the SPoS application. In the second experiment, SPoS was introduced two weeks after nematode inoculation. The SPoS treatments without soil were not evaluated in the second experiment. Both experiments were monitored over a three-month period. Each screenhouse treatment contained four plants and was replicated thrice. In the first experiment, data were collected on changes in soil nutrient content, below- and aboveground biomass, root deaths, root necrosis due to nematode damage, and R. similis population in root tissues and soil. In the second experiment, data were collected on root deaths and the number of nematodes in root tissues and the soil. The SPoS improved crop biomass yield, reduced root damage, and colonization by R. similis. The potential of SPoS to improve the management of R. similis and banana production under field conditions needs to be determined. Full article

The roles of endophytes in Cannabis sativa (cannabis, hemp) remain poorly explored. While in vitro studies suggest that there can be several benefits, such as plant growth promotion and protection against pathogens, more in planta studies are needed. This review summarizes the bacterial and fungal endophytes previously reported in tissues of C. sativa and discusses the factors influencing their presence, as well as their potential beneficial and detrimental effects. Using genome sequencing and culture-based approaches, we describe the microbial diversity in hydroponically cultivated cannabis plants at several developmental stages. These include mother plants, cuttings, vegetative and flowering plants, and tissue-cultured plantlets. Microbes that were present include fungal, yeast, and bacterial endophytes found in roots, stems, leaves, inflorescences, and seeds. These may have originated from the growing substrate or be transmitted through vegetative propagation. Notable endophytes included Rhizophagus irregularis (a mycorrhizal fungus), Penicillium chrysogenum (an antibiotic producer), and various endophytic yeast species not previously described in C. sativa. Endophytes representing potential plant pathogens, such as Fusarium oxysporum, are also present within cannabis tissues, which can negatively impact plant health. Using scanning electron microscopy, we observed that fungal propagules are present within pith parenchyma cells and xylem vessel elements in stem tissues, illustrating for the first time the in situ localization and distribution of endophytes in cannabis vascular tissues. The mechanism of spread through xylem vessels likely contributes to the spread of endophytes within cannabis and hemp plants. Further research is required to validate the roles of endophytes in cannabis and hemp plants grown under commercial production conditions. Full article

Apical dominance and culture heterogeneity significantly limit the efficiency of olive micropropagation, hindering the rapid production of plantlets. This study explores how manipulating the explant origin (topophysis) and density can mitigate these challenges. Explants originating from apical and middle sections were cultivated at densities of 18, 24, and 30 explants per vessel. After 12 weeks, significant differences in the growth parameters were observed based on the explant origin and density. The middle-section explants exhibited superior shoot proliferation and node production, especially at higher densities. The callus weight also increased with the density, while the internode length remained relatively stable. Hormone analysis demonstrated the density-dependent spatial distribution pattern of aromatic and isoprenoid cytokinins. Notably, at higher densities, the aromatic free bases in the apical-section leaves showed migration toward the shoot apices, while this migration was less pronounced in the middle-section leaves. Isoprenoid cytokinins displayed complex distribution patterns, with free bases and O-glucosides often increasing toward the basal nodes. These findings demonstrate that optimizing the explant origin and density can effectively reduce apical dominance and enhance culture homogeneity in olive micropropagation. This approach offers a promising strategy for improving the micropropagation protocols for olive and potentially other woody plants, leading to more efficient and cost-effective production of high-quality plantlets for commercial use. Full article