Naphthaleneacetic Acid Research Articles

Refinement of the in vitro propagation process of Petunia (Petunia hybrida) plant

Petunia (Petunia hybrida) is currently one of the most favored ornamental potted flowers. Tissue culture-based propagation has proven to be effective in terms of multiplication rates and consistent seedling quality, meeting the demand for Purple Petunia varieties. In this study, Sodium hypochlorite (NaOCl) with various culture media [Murashige and Skoog (MS), ½ MS, and Knudson C] and growth regulators [6-benzyladenine (BA), Indole 3-butyric acid (IBA), and Naphthaleneacetic acid (NAA)] were utilized to determine the appropriate concentrations and durations for sample sterilization, shoot multiplication, and root induction processes of Purple Petunia. Evaluation criteria for in vitro Purple Petunia included parameters, such as survival rate, contamination rate, dead samples, number of shoots, shoot height, number of roots, and root length. The results indicated that stem sample sterilization at a 5% NaOCl concentration for 10 min yielded the highest survival rate (70.7%) at 14 days post-culture initiation. Purple Petunia stem samples, when cultured in MS medium supplemented with 0.5 mg/L BA combined with 0.1 mg/L IBA, demonstrated the most efficient shoot multiplication with a multiplication rate of 26.9, a shoot weight of 3.6 g, a leaf/shoot ratio of 4.6, and a shoot height of 3.0 cm. The MS medium supplemented with 0.1 mg/L NAA was found to be optimal for root induction, resulting in the highest number of roots at 32.1 roots/plant and a root length of 7.0 cm. Briefly, this research provided fundamental insights into the in vitro propagation process of disease-free Purple Petunia multiplication.

The combined analysis of transcriptome and phytohormone provides new insights into signaling mechanism for lateral root formation of tea plant (Camellia sinensis)

The growth and development of lateral roots (LRs) determine the nutrient absorption and environmental adaptability of tea plant, playing a crucial role in the economic efficiency of tea plantations. However, the molecular mechanisms underlying the formation of LRs in tea plant remain unreported. In this study, we established a LRs induction system in tea plants by exogenously adding N-1-naphthylphthalamic acid (NPA) and naphthaleneacetic acid (NAA). The molecular mechanisms of LRs formation were analyzed through transcriptomics and endogenous hormone measurements. Results showed that NAA treatment could counteract the inhibitory effect of NPA on LRs formation and promote the generation of LRs in tea plant. The addition of exogenous NAA reduced the levels of auxin and zeatin in the root tips while increasing the content of abscisic acid (ABA). Transcriptomic analysis at four time points (2, 6, 12, and 24 h) after NAA vs. MOCK treatment revealed 78 different expression genes (DEGs) associated with plant hormone signaling pathways. Among these, the auxin signaling pathway was the most significant in responding to the LRs formation in tea plant. Weighted Gene Co-Expression Network Analysis (WGCNA) identified the Mitogen-Activated Protein Kinases (MAPK) signaling pathway as responsive to NAA treatment, participating in the formation of LRs in tea plant. This study provides potential signaling pathways for the investigation of LRs formation in tea plant and identifies candidate genes for further research into tea plant root system architecture (RSA).

Comparative Transcriptome Analysis of Non-Organogenic and Organogenic Tissues of Gaillardia pulchella Revealing Genes Regulating De Novo Shoot Organogenesis

Gaillardia pulchella is an important plant species with pharmacological and ornamental applications. It contains a wide array of phytocompounds which play roles against diseases. In vitro propagation requires callogenesis and differentiation of plant organs, which offers a sustainable, alternative synthesis of compounds. The morphogenetic processes and the underlying mechanisms are, however, known to be under genetic regulation and are little understood. The present study investigated these events by generating transcriptome data, with de novo assembly of sequences to describe shoot morphogenesis molecularly in G. pulchella. The RNA was extracted from the callus of pre- and post-shoot organogenesis time. The callus induction was optimal using leaf segments cultured onto MS medium containing α-naphthalene acetic acid (NAA; 2.0 mg/L) and 6-benzylaminopurine (BAP; 0.5 mg/L) and further exhibited a high shoot regeneration/caulogenesis ability. A total of 68,366 coding sequences were obtained using Illumina150bpPE sequencing and transcriptome assembly. Differences in gene expression patterns were noted in the studied samples, showing opposite morphogenetic responses. Out of 10,108 genes, 5374 (53%) were downregulated, and there were 4734 upregulated genes, representing 47% of the total genes. Through the heatmap, the top 100 up- and downregulating genes’ names were identified and presented. The up- and downregulated genes were identified using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Important pathways, operative during G. pulchella shoot organogenesis, were signal transduction (13.55%), carbohydrate metabolism (8.68%), amino acid metabolism (5.11%), lipid metabolism (3.75%), and energy metabolism (3.39%). The synthesized proteins displayed phosphorylation, defense response, translation, regulation of DNA-templated transcription, carbohydrate metabolic processes, and methylation activities. The genes’ product also exhibited ATP binding, DNA binding, metal ion binding, protein serine/threonine kinase -, ATP hydrolysis activity, RNA binding, protein kinase, heme and GTP binding, and DNA binding transcription factor activity. The most abundant proteins were located in the membrane, nucleus, cytoplasm, ribosome, ribonucleoprotein complex, chloroplast, endoplasmic reticulum membrane, mitochondrion, nucleosome, Golgi membrane, and other organellar membranes. These findings provide information for the concept of molecular triggers, regulating programming, differentiation and reprogramming of cells, and their uses.

Overexpression of the RAV Transcription Factor OsAAT1 Confers Enhanced Arsenic Tolerance by Modulating Auxin Hemostasis in Rice.

Characterization of arsenic (As)-responsive genes is fundamental to solving the issue of As contamination in rice. Herein, we establish the involvement of an RAV transcription factor OsAAT1 (Arsenic Accumulation and Tolerance 1) in regulating As response in rice. The expression of OsAAT1 is significantly higher in roots and stems of rice seedlings and is clearly upregulated by higher concentrations of arsenite [As(III)]. Compared with wild-type (WT) plants, OsAAT1-overexpressed transgenic lines (OE-OsAAT1) exhibit tolerance, while OsAAT1-knockout mutants (Osaat1) are sensitive to As(III) stress. Notably, the application of exogenous 1-naphthylacetic acid (NAA) greatly enhances the As tolerance of WT and transgenic lines, with stronger effects on OE-OsAAT1. The change in OsAAT1 expression leads to the alteration of As and auxin accumulation in transgenic plants by regulating the expression of OsLsi1, OsLsi2, OsCRL4, and OsAUX1 genes. Moreover, overexpression of OsAAT1 accelerates ROS scavenging and phytochelatins (PCs) synthesis, especially with the addition of exogenous NAA. OsAAT1 localizes in the nucleus and works as a transcriptional suppressor. OsGH3-12, belonging to the auxin-responsive GH3 gene family, is the downstream target gene of OsAAT1, whose expression is extensively downregulated by As(III). These findings provide new insights into As response via auxin signaling pathway in rice.

Accumulation of podophyllotoxin in the root culture of Hyptis suaveolens (L.) Poit: A potential natural lignan for clinically useful anticancer drugs

Podophyllotoxin (PTOX) is a natural antiviral, antirheumatic and anticancer molecule, but it is expensive to chemically synthesize. The present study aimed to evaluate growth and PTOX accumulation in root cultures of Hyptis suaveolens treated with different concentrations of auxins, vitamins and myo-inositol. Root cultures grown in liquid medium supplemented with different concentrations of indole-3-butyric acid (IBA), 1-naphthaleneacetic acid (NAA), vitamins and myo-inositol were used to measure biomass production and PTOX content. PTOX quantitation was performed via high-performance liquid chromatography with diode-array detection (HPLC-DAD) using a newly developed analytical method after successful validation. Root culture in MS medium supplemented with 1 mg L−1 IBA +0.5 mg L−1 NAA resulted in the highest root dry weight (248.76 mg) and the highest PTOX concentration in the roots (179.97 μg g−1 root). The roots cultured in liquid MS medium supplemented with 1 mg L−1 IBA +0.5 mg L−1 NAA presented the greatest increase in root biomass and PTOX content. This adequate balance of vitamin and myo-inositol supplementation in liquid MS culture medium increased the root dry weight and PTOX content.

Alteration in certain growth, biochemical, and anatomical indices of grapevine (Vitis vinifera) in response to the foliar application of auxin under water deficit.

Drought-induced stress represents one of the most economically detrimental natural phenomena impacting grapevine (Vitis vinifera ) development, yield, and fruit characteristics. Also, auxin is one of the most important plant growth regulators that can reduce damage caused by stress in plants. In this study, the impact of exogenously sprayed auxin (0, 50, and 200mgL-1 ) on growth, biochemical, and anatomical parameters was investigated in two grapevine varieties (cvs. 'Rashe' and 'Fakhri') under water deficit. According to our findings, water deficit led to a notable decrease in growth, protein content, and anatomical parameters; but significantly enhanced electrolyte leakage. Grapevines exposed to water deficit exhibited substantial increases in total phenolic compounds and antioxidant activity. Applying 50mgL-1 napthalene acetic acid (NAA) reduced the effects of water deficit in both grapevine cultivars by decreasing electrolyte leakage (15% in 'Rashe' and 20% in 'Fakhri'), and accumulating protein content (22% 'Rashe' and 32% 'Fakhri'), total phenolic compounds (33%'Rashe' and 40% 'Fakhri'), and antioxidant capacity (11% 'Rashe' and 39% 'Fakhri'); anantomical parameters were also improved. However, application of 200mgL-1 NAA had adverse effects on growth and biochemical traits of grapevines, with a more pronounced impact on root growth and anatomical parameters compared to other NAA concentrations. In conclusion, the application of 50mgL-1 NAA enhanced grapevine growth, enabling them to better thrive under water deficit.

Influence of IBA and NAA on Rooting of Terminal Cuttings of Chrysanthemum (Dendranthema grandiflora L.)

The present investigation was conducted at the Agricultural College and Research Institute, Vazhavachanur, Tiruvannamalai to study the effect of Indole-3-Butyric Acid (IBA) and Naphthalene Acetic Acid (NAA) on the rooting of terminal cuttings of chrysanthemum. An application of growth regulators (IBA and NAA) had a positive effect on the rooting of chrysanthemum terminal cuttings. The result of the experiment revealed that the treatment of IBA @ 400ppm significantly increased rooting percentage (89%), length of roots (5.67 cm), root spread (39.18 cm), number of roots (22.67), fresh weight of roots (4.94 g), plantlet weight (1.17 g), and plant height (8.87 cm) followed by NAA @ 400 ppm (79.33%), while minimum rooting percentage (47) was observed in control. It can be concluded that the treatment of IBA @ 400ppm significantly increased rooting percentage, roots length, number of roots, plantlet weight and plant height has greater survival percentage in the terminal cuttings of chrysanthemum (Dendranthema grandiflora).

Establishment of a Highly Efficient Micropropagation System of Aquilaria crassna Pierre ex Lecomte

Aquilaria crassna Pierre ex Lecomte is a principal species renowned for its production of agarwood. However, the active components of agarwood are not universally in compliance with the standards set by the Chinese Pharmacopoeia. We have identified an elite A. crassna tree with agarotetrol and alcohol extract levels that exceed these standards and have successfully established a stable in vitro micropropagation system using stem segments from this elite tree. The effects of auxins and minerals on axillary-bud induction, shoot multiplication, and rooting were investigated. The most effective medium for axillary-bud induction was a half-strength Murashige and Skoog (1/2MS) medium supplemented with 0.50 mg/L 6-benzylaminopurine (6-BA), achieving an induction rate of 53.33% with minimal hyperhydricity. The optimal shoot proliferation medium was an MS medium with 0.40 mg/L 6-BA, yielding a propagation coefficient of 2.96 without hyperhydricity. The best rooting medium comprised quarter-strength MS (1/4MS) macroelements and 1/2MS microelements with 0.10 mg/L naphthaleneacetic acid (NAA), resulting in an 82.54% rooting rate. Substrate effects on transplant survival and growth were also evaluated, and peat soil was identified as the best substrate, achieving a survival rate of 96.67%. This study introduces a straightforward and efficient in vitro micropropagation system utilizing mature A. crassna as explants. It holds significant importance for the consistent production of agarwood that complies with the standards of the Chinese Pharmacopoeia and provides a model for the targeted breeding of medicinal plants.

Development of efficient and scalable regeneration tissue culture method for Cannabis sativa

Large scale production of uniform disease-free plants is crucial for Cannabis sativa biotechnology. Existing micropropagation protocols rely heavily on shoot multiplication from existing meristems via direct organogenesis. Such protocols do not allow multiplication of plant material through continuous sub-culturing. Protocols that use indirect regeneration are usually not efficient enough and have very low multiplication rates. In the present study, an efficient protocol that uses a combination of direct organogenesis and callogenesis to induce multiple shoot development cultures is developed. Callogenesis was induced from various explants cultured on the media having various combinations of thidiazuron (TDZ) and naphthaleneacetic acid (NAA); best callogenesis and shoot regeneration was achieved from hypocotyl explants cultured on TDZ 0.4mgl-1 NAA 0.2mgl-1. Hypocotyls with cotyledonary node and shoot apical meristem were significantly better for shoot regeneration than explants without it. Shoots obtained from multiple shoot cultures were successfully rooted and then acclimatized under greenhouse conditions to develop into adult cannabis plants.

Effect of pre-harvest application of potassium nitrate, naphthalene acetic acid and ethephon on ripening and shelf-life of guava cv. Allahabad Safeda

The current study, effect of pre-harvest application of potassium nitrate (KNO3), naphthalene acetic acid (NAA) and ethephon on ripening and shelf-life of guava (Psidium guajava L.) cv. Allahabad Safeda was undertaken at the Fruit Research Farm, Dr B R S Agri at Sri Muktsar Sahib, Punjab. The experiment was carried out on an eight-year-old guava tree of the Allahabad Safeda. The trees were sprayed with various doses of chemicals, KNO3 (1.0, 1.5, 2.0%), NAA (200, 300, 400 ppm) and ethephon (200, 400, 600 ppm) during the third week of November. The fruits were harvested at the hard ripe stage on 19 December, placed in Corrugated fibre box (CFB) of 4 kg capacity and stored at ambient temperature. In ambient storage, guava fruits were remain acceptable for up to 6 days of storage without any adverse effect on fruit quality. KNO3 (1.5 and 2.0%), NAA (300 ppm) and ethephon (200 ppm) recorded a reduction in physiological loss of weight and spoilage and KNO3 (2.0%) maintaining fruit firmness (7.64 kg/cm2), palatability rating (8.00) throughout the storage period. However, the highest storage life and good-quality fruits was recorded with the application of KNO3 (1.5, 2%) during ambient storage. At lower concentrations, ethephon also helps to enhance the ripening of fruits, contrast to this fruits treated with NAA delayed the fruit senescense.

Effect of chemical thinning on fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘Khalal’ stage

The aim of this research work was to study the effect of chemical thinning using NAA (Naphthalene acetic acid) and the manual thinning used by the farmer on the fruit growth and fruit quality of ‘Majhoul’ date palm at the end of the ‘khalal’ stage (color stage and fruit physiologically mature). Trials were carried out on an adult plantation in the Tinejdad region, Tafilalet area. Observations focused on monitoring the fruit growth of different flowering phases and fruit quality at the end of the ‘khalal’ stage. Obtained results showed that the evolution of the fruit size parameters is similar for all flowering phases and all thinning treatments and at the end of the ‘khalal’ stage there is no significant difference (p ˃ 0.05) between flowering phases and between thinning treatments for these parameters. At the end of the ‘khalal’ stage, fruit length is between 4.8 and 4.9 cm and fruit mass is between 25.0 and 25.5 g. The content of sugar in the fruit is higher at the manual thinning treatment than at the NAA treatments, whereas the flowering phases have no effect on this parameter. The pH of the fruit juice is relatively similar for all thinning treatments and all flowering phases.

Comparison of the content of active compounds in cell suspensions and aqueous extracts of Rosmarinus officinalis L. with those in the Endophytic fungus Alternaria alternata

The current study was carried out to detect the active compounds in both the aqueous extract of a Rosmarinus officinalis L. plant and the extract of cell suspensions and compare with the extract of the endophytic fungus Alternaria alternata isolated from the leaves of a R. officinalis plant. Callus was induced from the leaves of rosemary plants, and the highest induction of callus formed reached 100% when treated with a concentration of 1-Naphthaleneacetic Acid (NAA)2.0 mg. L-1, compared to the control treatment, which had an induction rate of 0%. the highest fresh weight of callus was 1.628 gm in the presence of NAA. The callus induced in the presence of NAA was charactrized by its fragile texture. cell suspensions were also obtained from it. fungus extract was superior in its content of active compounds to the aqueous extract and cell suspension cultures at 21 days. The total alkaloid content which were 6.65%, phenolic content were 117.25 mg.gm, flavonoid content were 104.35 mg.gm, total terpenoid content was 6.65%, total steroid content was 6.05% and the concentration of rosmaric acid was 154.7%. The results of the current study confirm the single receptor of endophytic fungi isolated from medicinal plants as one of the important sources of effective compounds.

Temporary Immersion Bioreactor (TIB) System for Large-Scale Micropropagation of Musa sp. cv Kluai Numwa Pakchong 50

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.

Feasible biosynthesis of biologically active metabolites in in vitro culture of Macrotyloma uniflorum

Macrotyloma uniflorum, commonly called “Horse gram” is an underutilized pulse crop recognized for its great nutritional significance and a broad range of biological properties. There have been no in vitro studies for the biosynthesis of enhanced bioactive metabolites in the callus culture of M. uniflorum. In the study reported here, we have designed a feasible protocol for high-frequency callus induction and maintenance utilizing a leaf as an explant grown on MS media enriched with various concentrations of different plant growth regulators (PGRs) including α-naphthalene acetic acid (NAA), 6-benzylaminopurine (BAP) and thidiazuron (TDZ) either alone or in combination. Among all the tested PGRs, NAA alone resulted in high-frequency callus induction (97%), and maximum biomass accumulation (Fresh weight (FW): 200 g/L: Dry weight (DW): 20.4 g/L). Moreover, hormonally optimized callus cultures exhibit maximum production of phenolic compounds (166.6 mg/L) and flavonoid compounds (351.6 mg/L). The antioxidant potential of calli extracts was also determined by utilizing various antioxidant activities. Maximum antioxidant activities ((2,2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid)) ABTS = 497.9; TEAC μM; (Ferric reducing antioxidant power) FRAP = 823 TEAC μM; (Cellular Antioxidant Activity) CAA: 58.2%) were recorded in leaf-derived calli supplemented with different PGRs treatments. High-performance liquid chromatography (HPLC) analysis further revealed maximum biosynthesis of caffeic acid (1.63 mg/g DW), gallic acid (8.92 mg/g DW), kaempferol (0.71 mg/g DW), myricetin (0.39 mg/g DW), apigenin (0.64 mg/g DW) at 10 mg/L BAP and isorhamnetin (0.68 mg/g DW) at 1 mg/L TDZ + 10 mg/L NAA. The objective of this study was to explore in vitro biosynthesis of enhanced bioactive metabolites in the callus culture of M. uniflorum, leveraging a feasible protocol for high-frequency callus induction and maintenance. The results showcase the remarkable efficacy of NAA in callus induction and biomass accumulation, highlighting the hormonally optimized callus cultures as a potent source for enhanced biosynthesis of bioactive metabolites, paving the way for further applications in pharmaceutical and commercial industries.

IN VITRO PROPAGATION COLLA AROMATIC ROXB

This experiment was tested the propagation of Colla aromatica Roxb with tissue culture, the study objective to study of propagation possibility of Colla aromatica Roxb (Homalomena aromatica Schott. Araceae), this study found the possibility of disinfecting Colla aromatica Roxb using sodium hypochlorite solution in contains of 15 and 20 for 5 and 10 minutes, bacteria contamination was 0%, fungal contamination was 14.29%, the survival rate was 85.71% At the same time without Chemicals stimulate growth of plant, can't cause callus form callus in the case . After rearing young shoots of for 30 days, feeding Benzyl Adenine Pure (BAP) at a contains of 3 mg/l combined with Naphthalene Acetic Acid (NAA) at a contain of 1 mg/l, there was a high number of shoots 1.88 shoots, but at the same time, giving NAA only was found to be statistically different. after culture the shoots in Agar media for 60 days, it was found that the result of giving NAA combined with BAP for the elongation of the shoot is not statistically different, from the observation that giving NAA combined with BAP with a high contains, will have the characteristics of the shoot elongation that is better than giving NAA combined with low contains

The Elimination of Viroids through In Vitro Thermotherapy and a Meristem Tip Culture from a New Limonime Hybrid (Citrus x limon var. limon (L.) Burm. f. x Citrus latifolia var. latifolia)

Viruses and viroids pose a significant challenge in citriculture, and their control is crucial for plant health. This study evaluated the effectiveness of in vitro thermotherapy combined with a meristem tip culture for eliminating citrus exocortis viroid (CEVd) and hop stunt viroid (HSVd) from a new limonime hybrid (Citrus x limon var. limon x Citrus latifolia var. latifolia). The elimination success was confirmed by RT-PCR assays. The in vitro elimination rate for CEVd during the shoot proliferation stage (43%) was higher than for HSVd (21%). Accordingly, in the subsequent rooting stage, the in vitro elimination rate for CEVd (50%) was higher than for HSVd (33%). Successful CEVd and HSVd eradication at a 100% rate was confirmed in the ex vitro acclimatized plants in the greenhouse. The study also established an efficient micropropagation protocol. The optimal treatment for in vitro shoot induction was 0.5–2 mg L−1 benzyladenine (BA) + 0.5 mg L−1 gibberellic acid (GA3) + 0.25 mg L−1 naphthalene acetic acid (NAA), while for shoot elongation, it was 0.5 mg L−1 BA + 0.5 mg L−1 kinetin (KIN) + 0.5 mg L−1 GA3 + 0.25 mg L−1 NAA. Rooting was best promoted by 1 mg L−1 NAA. This study provides valuable insights for the mass production of viroid-free propagation material in this new lemon x lime hybrid, contributing to the conservation of genetic resources in citrus breeding programs through the combined application of in vitro thermotherapy and an in vitro meristem tip culture, a novel and highlighted achievement reported for the first time in this study.

Silicon nanoparticle(s) induced morpho-anatomical traits and improved micropropagation of white fleshed dragon fruit [Selenicereus undatus (Haworth)]

Silicon nanoparticles (SiNPs) improve plant growth and yield by enhancing nutrient uptake and stress tolerance. These nanoparticles boost plant defense mechanisms against pathogens and environmental challenges. In this study, seedlings-derived explants of white-fleshed dragon fruit (Selenicereus undatus) were used for differentiation and high-frequency shoot regeneration on Murashige and Skoog (MS) medium with 6-benzylaminopurine (BAP, 0.5 mg L−1) and α-naphthalene acetic acid (NAA, 0.25 mg L−1). The complementation of 3.0 mg L−1 SiNPs in the optimized nutrient medium enhanced the shoot multiplication rate to 23.0 cladodes per explants. The regenerated cladodes were structurally well-suited with thick cuticles, well-developed epidermis, hypodermis, aquiferous cortex, and collateral vascular bundles compared to the control and other concentrations of SiNPs tested. SiNPs promoted the development of 3-5 aerial and adventitious roots per cladode enabling preferred direct hardening of cloned plants on soilrite ex vitro. The morphological transformations improved by SiNPs, including the formation of robust cladode and spines, played a pivotal role in achieving a high rate of acclimatization success (96%) in the field. The incorporation of SiNPs in vitro at the shoot amplification stage of micropropagation of S. undatus induced morphogenesis and structural changes, and promoted qualitative and quantitative improvements in the regenerated cladodes which helped in enhanced survival of plants in vivo.

Synergistic effects of nitrogen and naphthalene acetic acid on growth, yield and nutritional content of Stevia (Stevia rebaudiana Bertoni)

Stevia farming in Bangladesh is increasingly significant due to limitations in cane sugar production and the rise in diabetic cases. This study examined how nitrogen and naphthalene acetic acid (NAA) affect Stevia development, production and nutritional content on the experimental farm of the regional station of the Bangladesh Sugarcrop Research Institute, Thakurgaon. Various nitrogen treatments (N1: untreated, N2: 105 kg ha-1, N3: 140 kg ha-1, N4: 175 kg ha-1, N5: 210 kg ha-1) and NAA applications (H1: untreated, H2: 50 mg/L, H3: 100 mg/L, H4: 150 mg/L) were administered employing a randomized complete block design (RCBD). Results showed that N3 and H3 treatments produced the highest yield, averaging 10.06 % more than other doses. Stevia leaf nutrients like nitrogen (3.47 %), potassium (0.19 %) and magnesium (0.15 %) were also influenced by N3H3 treatment. The study suggests that for Stevia cultivation in northern Bangladesh, an optimal nitrogen application rate of 140 kg ha-1 and an NAA concentration of 100 mg/L are recommended.

Efficient and rapid in vitro micropropagation of MD2 and H4 pineapple varieties

Pineapple plays an important role in international trade and supports of more than a million households in Côte d’Ivoire. However, its yield is subject to pedoclimatic problems and erosion of genetic potential of plant material. This study aims to establish an effective in vitro yield protocol for MD2 and H4 pineapple varieties. Therefore, the effects of 6-benzylaminopurine (BAP) combined with different concentrations of 2-isopentenyladenine (2-iP), with variable light intensity and activated charcoal on leaf shoot proliferation and elongation were tested. Analysis of variance revealed that Murashige and Skoog medium (MSB5) supplemented with 2 mg/L BAP combined with 0.25 mg/L 2-iP recorded the highest average number of microshoots (13.50 microshoots) in MD2 variety, while 2 mg/L of BAP combined with 0.5 mg/L of 2-iP recorded the best average number of shoots (15.20 microshoots) in H4 variety. Maximum microshoot elongation (7.81 cm and 7.03 cm for MD2 and H4, respectively) was obtained with 2 mg/L BAP combined with 0.25 mg/L of 2-iP. Light intensity of 1500 lux produced 14.06 and 14.86 microshoots in MD2 and H4, respectively. In contrast, maximum microshoot elongation (4.40 cm and 4.13 cm in MD2 and H4, respectively) was recorded at 2000 lux light intensity. A 2 g/L of activated charcoal inhibited microshoot proliferation. However, it induced an elongation of 7.50 cm in MD2 and 7.07 cm in H4. Microshoots were rooted on MS medium supplemented with 100 mg/L myo-inositol, 30 g/L sucrose, 200 mg/L glutamine, 1 mg/L naphthalene acetic acid (NAA), 2 mg/L indole-3-butyric acid (IBA), 2 g/L activated charcoal, all solidified with 6g/L agar. In conclusion, the combination of 2 mg/L BAP and 2-iP (0.25 - 0.5 mg/L) is recommended for better in vitro shoot proliferation in MD2 and H4 varieties. Light intensities of 1500 - 2000 lux are ideal for better shoot proliferation and elongation. Finally, the addition of 2 g/L activated charcoal to the medium improves shoot elongation and rooting in MD2 and H4 varieties.

Plant biotechnology for the conservation of Argania spinosa (Skeels L): optimising propagation and sustainable valorisation

ABSTRACT Argania spinosa, an endangered species from southwestern Morocco, is studied for preservation through plant biotechnology. The research aims to optimise argan tree propagation to boost production, preserve heritage, and use residual species. In vitro seedlings are transferred to a modified Murashige and Skoog medium with various phytohormones. Six combinations of auxins and cytokinins are tested for germination. Results show that a liquid medium with activated charcoal from argan shells promotes stem elongation. Meta-topoline at 0.5 mg L−1, combined with naphthalene acetic acid (NAA) at 0.2 mg L−1, enhances shoot growth, leaf formation, and callogenesis. Adding benzylaminopurine (BAP) at 0.1 mg L−1 and indole-3-butyric acid (IBA) at 0.02 mg L−1 to the medium elongates stems by 4.3 cm after 21 days. A 2000 ppm IBA concentration is key for a 90% rooting rate. These findings underscore plant biotechnology’s role in preserving and propagating argan trees, improving resource management, and supporting sustainability.