Percentage Of Regeneration Research Articles

Silver nitrate reduces hyperhydricity in shoots regenerated from the hypocotyl of snapdragon cv. Maryland Apple Blossom

• Ethylene is involved in shoot regeneration and process of hyperhydricity. • AgNO 3 improved shoot regeneration and reduced hyperhydricity in regenerated plants. • Shoots regenerated from AgNO 3 -containing media easily developed into normal plants. We developed an efficient protocol for shoot regeneration from hypocotyl explants in snapdragon ( Antirrhinum majus L.) cv. Maryand Apple Blossom by plant growth regulators (PGRs), followed by ethylene synthesis inhibitor Aminoethoxyvinylglycine (AVG), ethylene precursor 1-Aminocyclopropane-1-carboxylate (ACC), and ethylene action inhibitor silver nitrate (AgNO 3 ). The combination of benzyladenine (BA) and 2,4-dichlorophenoxyacetic acid (2,4-D) did not induce shoots, whereas naphthaleneacetic acid (NAA) and Zeatin (Zt) induced shoots. The combination of 0.05 mg/L NAA and 2.5 mg/L Zt resulted in the maximum shoot regeneration percentage and a reasonable number of shoots per explant. However, the regenerated shoots exhibited hyperhydricity and failed to develop into normal plants when introduced into plant growth media. Addition of ACC and AVG to the media containing 0.05 mg/L NAA and 2.5 mg/L Zt inhibited shoot regeneration, while AgNO 3 (2.0 mg/L) marginally improved shoot regeneration and successfully reduced hyperhydricity. Shoots grown in AgNO 3 -containing media showed a reduction in ethylene related gene expression and reactive oxygen species (ROS) accumulation; the leaves showed reduced intercellular space as well as an increase in the number of open stomata under AgNO 3 treatment. Moreover, shoots regenerated from AgNO 3 -containing media easily developed into normal plants in plant growth medium. This study highlights the importance of specific PGRs in shoot regeneration, as well as the role of AgNO 3 in reducing the hyperhydricity of shoots regenerated in vitro . These findings will contribute to a better understanding of the hyperhydricity mechanism. We expect this protocol to be useful for in vitro shoot regeneration and genetic transformation of the snapdragon cultivar used in this study.

Study on regeneration characteristics of choline chloride-monoethanolamine deep eutectic solvent after capturing CO2 from biogas

Choline chloride-monoethanolamine deep eutectic solvent (ChCl-MEA DES) can deeply remove CO2 from biogas. This study focused on regeneration of ChCl-MEA DES after CO2 capture. The effects of regeneration temperature, time and water content on CO2 absorption capacity, absorption rate and CO2/CH4 absorption selectivity after regeneration were evaluated. The addition of HZSM-5 catalyst during regeneration further promoted regeneration efficiency. FTIR and NMR indicated that carbamates were formed after absorption, and water made it easier for the amino group to react with CO2 to form carbamates. The highest regeneration percentage of absorbent was up to 99.89%, and the CO2 absorption capacity even didn’t decrease significantly after 8 cycles. The ideal regeneration energy consumption in the experiment was also evaluated. This research provided a valuable reference for the application of this absorbent in CO2 purification of biogas.

Axonal Regeneration Through Autologous Grafts: Does the Axonal Load Influence Regeneration?

Two-stage free functional muscle transfers for long-standing facial palsy can yield unpredictable results. Earlier studies have demonstrated incomplete regeneration across neurorrhaphies in native nerve and higher donor axonal counts correlating with improved outcomes but axonal count in nerve grafts have not been as thoroughly reviewed. To investigate the impact of varying axonal counts in autologous grafts on functional outcomes of repair. Animals were allocated into three groups: Direct Nerve Repair (DNR, n=50), Small Nerve Graft (SNG, n=50), and Large Nerve Graft (LNG, n=50). All grafts were inset into the Posterior Auricular Nerve with ear movement recovery (EMR) monitored as functional outcome. At various postoperative weeks (POWs), excised specimens were imaged with electron microscopy. Axonal counts were measured proximal to, distal (DAC) to, and within grafts. Total Success Ratio (TSR) was calculated. In DNR, DAC was significantly lower than proximal axonal counts at all POWs, with maximum TSR of 80%. TSR for LNG and SNG were significantly lower at all POWs when compared to DNR, with maximums of 56% and 38%, respectively. LNG had a significantly larger DAC than SNG at POW12 and beyond. A direct relationship was present between DAC and EMR for all values. Higher native axonal count of autologous nerve grafts resulted in higher percentage of regeneration across neurorrhaphies.

Establishment of an Efficient In Vitro Propagation Method for a Sustainable Supply of Plectranthus amboinicus (Lour.) and Genetic Homogeneity Using Flow Cytometry and SPAR Markers

Plectranthus amboinicus (Lour.) Spreng is a medicinally important aromatic perennial herb used for the treatment of skin diseases, constipation, asthma, flu, fever, cough, and headache as well as a flavoring ingredient in traditional drinks, food, and meat stuffing. In this study, a high-performance in vitro propagation system of P. amboinicus through direct shoot organogenesis was developed using axillary node explants cultured on MS (Murashige and Skoog) medium augmented with 0.5, 2.5, 5.0, 7.5, and 10.0 µM of 6-benzyladenine (BA) or kinetin (Kin), alone or with 0.1, 0.5, 2.5, and 5.0 µM of indole-3-acetic acid (IAA) or α-naphthalene acetic acid (NAA). To optimize the regeneration potential of node explants, the effects of basal media strength and pH were also investigated. After 8 weeks of culture, explants cultured in full strength MS basal medium (pH 5.7) with 5.0 µM BA and 2.5 µM NAA exhibited the highest percentage (97.1%) of regeneration and the maximum number (19.3) of shoots per explant. Individual elongated shoots were rooted on half strength MS basal medium containing 0.25 µM indole 3-butyric acid (IBA) after 4 weeks of culture, producing 5.3 roots/shootlets with a root induction frequency of 93.7%. First time genetic stability of in vitro raised P. amboinicus plants was determined using SPAR markers, such as DAMD and ISSR, as well as flow cytometric tests, assuring the availability of authenticated raw materials for commercial production of the plant and its bioactive components.

Salinity Stress Response of Rice (Oryza sativa L. cv. Luem Pua) Calli and Seedlings.

Soil salinity limits plant growth and production. This research investigated a suitable medium for callus induction and plantlet regeneration in the Luem Pua rice cultivar. The effect of salt stress on seedling growth was determined using in vitro culture and soil conditions. An efficient protocol for callus induction has been developed by culture sterilized seeds on the Murashige and Skoog (MS, 1962) medium containing 0.5 mg/l benzyladenine (BA) with 1 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D) that resulted in a 100% callus induction. Plantlet regeneration percentage of 49% was recorded on the MS medium containing 4 mg/l BA with 0.5 mg/l 1-naphthaleneacetic acid (NAA) after 4 weeks. For salt stress investigation, the calli were treated on an induction medium containing various concentrations of NaCl (0, 50, 100, 150, and 200 mM), while two-week-old rice seedlings were planted in soil and treated with the same concentration of NaCl for 4 weeks. In vitro culture revealed that callus survival percentage decreased when NaCl concentration increased, similar to soil culture. Seedling growth under salinity treatment also decreased when NaCl concentration increased, while other physiological parameters such as total chlorophyll, chlorophyll a, chlorophyll b, green intensity, and chlorophyll fluorescence under light conditions increased under salinity stress. These changes define the growth and physiological salinity tolerance characteristics of Luem Pua rice calli and seedlings. They can be utilized as a baseline for demand-driven in vitro rice propagation, providing useful information that can be combined with other agronomic features in rice development or breeding programs to improve the flexibility of abiotic stress-tolerant cultivars.

Nanoclay-reinforced HA/alginate scaffolds as cell carriers and SDF-1 delivery-platforms for bone tissue engineering

Bone tissue engineering has come on the scene to overcome the difficulties of the current treatment strategies. By combining biomaterials, active agents and growth factors, cells and nanomaterials, tissue engineering makes it possible to create new structures that enhance bone regeneration. Herein, hyaluronic acid and alginate were used to create biologically active hydrogels, and montmorillonite nanoclay was used to reinforce and stabilize them. The developed scaffolds were found to be biocompatible and osteogenic with mMSCs in vitro, especially those reinforced with the nanoclay, and allowed mineralization even in the absence of differentiation media. Moreover, an in vivo investigation was performed to establish the potential of the hydrogels to mend bone and act as cell-carriers and delivery platforms for SDF-1. Scaffolds embedded with SDF-1 exhibited the highest percentages of bone regeneration as well as of angiogenesis, which confirms the suitability of the scaffolds for bone. Although there are a number of obstacles to triumph over, these bioengineered structures showed potential as future bone regeneration treatments.

Genetic transformation of clone rootstock of stone fruits 146-2 using the green fluorescent protein reporter gene

For the form of dwarf winter-hardy clonal rootstocks of stone crops146-2 (Prunus pumilaL.xP.tomentosaThunb.), system of regeneration and genetic transformation using green fluorescent protein (GFP) has been developed. For eff ective regeneration of accessory shoots, no pre-treatment with 6-benzylamine-purine (BA) and auxin was required. Stimulation of the regeneration of shoots from leaf explants required 2-3 weeks of a dark period. Th e best percentage of regeneration (greater than 75 %) was observed with a combination of 3 mg/L BA and 0.75 mg/L IBA. The achieved regeneration effi ciency made it possible to develop a protocol for genetic transformation, mediated byAgrobacterium, for rootstock 146-2. Whole leaves from in vitro-cultured shoots were used as explants for transformation by theA. tumefaciensstrain CBE21, with the binary vector pBINmGFP5ER containing thenptIIencoding neomycin phosphotransferase II as a plant-selectable marker under the control of the NOS promoter (nopalin synthase) and the reportergfpgene encoding a green fluorescent protein under the control of the cauliflower mosaic virus (CaMV) promoter 35S. Th e integration ofnptIIandgfpinto transgenes was confirmed by PCR. Expression of the green fluorescent protein was observed using fluorescence microscopy. The efficiency of transformation based on PCR analysis of independent lines resistant to kanamycin was 0.41-0.83 %. All transgenic lines showed resistance to kanamycin at a concentration of 40 mg/L. They were rooted and acclimatized to greenhouse conditions. Th e developed protocols will be used to producePlum pox virus(PPV) resistant plants.

Development of methods for regeneration and genetic transformation of the commercial plum variety Startovaya from somatic tissues

An effi cient technique for regeneration of plants from somatic tissues of domestic plum (Prunus domestica L.) varieties, as well as selecting schemes using various reporter (uidA, gfp) and selective marker genes (nptII, hpt) have been developed. During the transformation of somatic tissues of the commercial plum variety, transgenic plants containing both reporter genes and genes of economically valuable traits were obtained. For the fi rst time, the eff ect of calcium pantothenate on the adventive regeneration of plum shoots was investigated. It was shown that the selective antibiotic hygromycin is more eff ective for the selection of plum transformants than kanamycin or geneticin, which was expressed in a higher frequency of transformation — 1.2-2.2 % versus 0.2-0.5 % in selection on kanamycin. When using geneticin, transgenic plants were not obtained. Optimization of conditions made it possible to increase the percentage of regeneration of shoots to 79.4 % for the variety Startovaya and up to 39.6 % for the variety Etude. Analysis of GFP expression in transgenic lines showed that the leader sequences of herbaceous plant species encoding signal peptides can be used to eff ectively cellular compartmentalization of heterologous gene expression products in the plum. Preliminary results also show a higher level of expression of the reticular form of GFP in comparison with the vacuolar and cytosolic forms. Nine transgenic lines containing the insertion of the target bar gene, which gives resistance to phosphinothricin-containing herbicides of the “Basta” type, were obtained, which was confi rmed by the presence in the genome of the sequence of the transferred gene and the resistance of the obtained transgenic plants to 3 times the fi eld concentration of the herbicide “Basta”.

Overexpressing Arabidopsis thaliana ACBP6 in transgenic rapid-cycling Brassica napus confers cold tolerance

BackgroundRapid-cycling Brassica napus (B. napus-RC) has potential as a rapid trait testing system for canola (B. napus) because its life cycle is completed within 2 months while canola usually takes 4 months, and it is susceptible to the same range of diseases and abiotic stress as canola. However, a rapid trait testing system for canola requires the development of an efficient transformation and tissue culture system for B. napus-RC. Furthermore, effectiveness of this system needs to be demonstrated by showing that a particular trait can be rapidly introduced into B. napus-RC plants.ResultsAn in-vitro regeneration protocol was developed for B. napus-RC using 4-day-old cotyledons as the explant. High regeneration percentages, exceeding 70%, were achieved when 1-naphthaleneacetic acid (0.10 mg/L), 6-benzylaminopurine (1.0 mg/L), gibberellic acid (0.01 mg/L) and the ethylene antagonist silver nitrate (5 mg/L) were included in the regeneration medium. An average transformation efficiency of 16.4% was obtained using Agrobacterium-mediated transformation of B. napus-RC cotyledons using Agrobacterium strain GV3101 harbouring a plasmid with an NPTII (kanamycin-selectable) marker gene and the Arabidopsis thaliana cDNA encoding ACYL-COA-BINDING PROTEIN6 (AtACBP6). Transgenic B. napus-RC overexpressing AtACBP6 displayed better tolerance to freezing/frost than the wild type, with enhanced recovery from cellular membrane damage at both vegetative and flowering stages. AtACBP6-overexpressing B. napus-RC plants also exhibited lower electrolyte leakage and improved recovery following frost treatment, resulting in higher yields than the wild type. Ovules from transgenic AtACBP6 lines were better protected from frost than those of the wild type, while the developing embryos of frost-treated AtACBP6-overexpressing plants showed less freezing injury than the wild type.ConclusionsThis study demonstrates that B. napus-RC can be successfully regenerated and transformed from cotyledon explants and has the potential to be an effective trait testing platform for canola. Additionally, AtACBP6 shows potential for enhancing cold tolerance in canola however, larger scale studies will be required to further confirm this outcome.

Post-exploitation bark recovery rates of some medicinal tree species in Ghana

• Over exploitation of tree bark for medicinal purposes has led to extinction of valuable tree species. • Debarked trees recover by developing edge and sheet regrowth and stress shoots. • Bark recovery of some medicinal tree species in Ghana is influenced by ecological zone, harvesting intensity and season. • Medicinal tree species respond differently to wood borer attacks. • Forest managers could allow minimum harvesting of medicinal tree species to prevent extinction of some tree species. Unregulated harvest of tree bark for medicinal purposes has led to overexploitation and extinction of some valuable tree species. The study assessed bark recovery rates of four medicinal tree species and determined their regenerative abilities, stress shoot production and susceptibility to wood borers. A total of 192 trees of Bombax buonopozense, Mangifera indica, Azadirachta indica and Blighia sapida were randomly selected outside protected forests in the Moist Semi-deciduous (MSD) and Guinea Savannah (GS) ecological zones of Ghana. The trees were harvested using three harvesting intensities, 25%, 50%, and 75% bark removal. Edge and sheet re-growth, stress shoot production and wood borer attack were recorded for each tree in twelfth months. Our results show that the bark of B. buonopozense (29.4% at MSD and 21.4% at GS), M. indica (22.3% at MSD and 16.1% at GS) and A. indica (13.5% at MSD and 12.8% at GS) showed higher regeneration percentage compared to B. sapida (3.8% at MSD and 3.7% at GS), while stress shoot growth percentage was limited to only B. buonopozense (4.7% at MSD and 25% at GS). Though no tree died during the study period, borer attack was recorded for all the species except A. indica . We recommend that forest managers should allow minimum harvesting of B. sapida as they showed slow recovery, while rotation period for repeated harvest can also be prescribed for B. buonopozense and M. indica . Moreover, the coppicing ability of B. buonopozense needs to be examined since it produced a higher number of stress shoots.

Adsorptive exclusion of crystal violet dye from wastewater by using fish scales as an adsorbent

Aim of this research paper was to investigate the potential of fish scales as an adsorbent for crystal violet dye exclusion from wastewater and to optimize various adsorption parameters for maximum adsorption of dye. Parameters studied were solution pH, adsorbent dose, contact time, dye concentration, and temperature. Results showed maximum percentage degradation, i.e., 90% under optimized conditions such as pH 12 solution, 0.4 g adsorbent dose, with 40 min of exposure time and 40 ppm of dye concentration at 10 °C solution temperature. Adsorbent was characterized using FTIR, and SEM techniques to explore the functionality and to study morphology of adsorbent, respectively. Results confirmed that carboxyl, amino, phosphate, and sulfonate groups and heterogeneous adsorbent surface was accountable for crystal violet dye adsorption on fish scales. of the fish scale was 8. Adsorption isotherms such as Langmuir, Freundlich, and D-R isotherm models were also investigated. Contact time data was applied to various kinetic models, i.e., pseudo-first order, and pseudo-second order kinetic models. Thermodynamic study was also investigated. Results confirmed that experimental data fitted well to Freundlich isotherm model (= 0.9983) and pseudo second order kinetic model (= 0.9970) as ARE error analysis values of these models were 1.191692 E + 06 and −160.66, respectively (lower than that of other models. Computed ΔG and ΔH values confirmed adsorption process to be spontaneous and of endothermic kind. Applicability of established procedure with tap water was 78% and regeneration percentage was 72% which showed the effectiveness of fish scales powder for removal of crystal violet dye from wastewater.

In vitro culture initiation and regeneration of two highly productive clones of poplar

In vitro shoot regeneration is a fast and reliable method for propagation of valuable tree genotypes and important step in genetic manipulations. This study aimed to establish an optimal in vitro culture initiation and regeneration protocol for highly productive poplar clones ‘Novoberlinska-3’ (Populus pyramidalis × P. laurifolia) and ‘Volosystoplidna’ (P. trichocarpa). In vitro culture was initiated either on MS (IM-MS) or WPM (IM-WPM) medium both containing BAP (0.2 mg.L-1) and IBA (0.1 mg.L-1). Results demonstrated that the best initiation medium for the clone ‘Volosystoplidna’ was IM-WPM on which 93.3 % of explants survived, while explants from ‘Novoberlinska-3’ better survived on IM-MS. After establishing both genotypes into aseptic culture, regeneration experiments were started using two types of explants, leaf and petioles, planted on callus induction medium containing 2iP (1.02 mg.L-1) and NAA (1.86 mg.L-1). Furthermore, microshoots were placed on shoot induction medium supplemented with 0.04 mg.L-1 thidiazuron, and then transferred on shoot elongation medium with 0.2 mg.L-1 BAP. Regeneration protocol showed better performance of poplar ‘Novoberlinska-3’, but it was also efficient for ‘Volosystoplidna’. Plant regeneration from leaf explants in the clone ‘Novoberlinska-3’ showed the highest regeneration percentage (92.3 %) and the number of shoots per explant (3.1), which significantly exceeded other explants. Our results showed a significant difference between the survivability of two clones during culture initiation. The differences in regeneration rates between the clones as well as leaf and petiole explants were also determined. Obtained aseptic cultures of highly productive poplar hybrids will be used in our further studies, especially for genetic transformation.

VARIACIÓN SOMACLONAL EN PLANTAS DE Phalaenopsis sp. var. Dudú REGENERADAS POR EMBRIOGÉNESIS SOMÁTICA DIRECTA

<p><strong>Background</strong>: Nowadays, a growing demand for hybrids of <em>Phalaenopsis</em> sp. exists to satisfy this demand it is necessary to develop protocols for massive propagation that ensure high percentages of clonal regeneration, such as somatic embryogenesis. Besides, studying genetic variation within regenerated plants offers a greater understanding of the suitability of the micropropagation protocol in relation with genetic stability of the materials used. <strong>Objective</strong>: The present research work aimed to evaluate three concentrations of two types of plant growth regulators (RCV). 6-benzylaminopurine cytokinin (BA) (1.0, 2.0 y 3.0 mgL<sup>-1</sup>) in combination with three concentrations of 2,4-diclorofenoxiacetic acid (2,4-D) (3.0, 4.0, 5.0 mgL<sup>-1</sup>), for the induction of somatic embryos. In addition, the genetic stability of the regenerated plants was analyzed using molecular markers type RAPD (Random Amplified Polymorphic DNA). <strong>Methodology</strong>: The induction of somatic embryogenesis was induced from two leaf explants with different stages of develop from 15-20 cm in height <em>Phalaenopsis</em> sp. var. Dudú seedlings, cultivated <em>in vitro</em>; first leaf as mature explant (PH) and third leaf as young explant (TH). <strong>Results</strong>: The highest number of regenerated plants was 29.8 at 135 days after the start of the culture (ddic) with 2.0 and 5.0 mgL<sup>-1</sup> of BA and 2,4-D, respectively, using TH as explant. In the morphogenetic response of the regenerated explants, a correlation was observed between the age of the explant and the RCV concentration. Polymorphic bands were observed with the four primers used, indicating somaclonal variation in regenerated plants. <strong>Implications</strong>: The results obtained provide an alternative for regeneration, as well as offering a methodology to initiate genetic improvement programs in <em>Phalaenopsis</em> sp. var. Dudú. <strong>Conclusions</strong>: <em>In vitro</em> regeneration of <em>Phalaenopsis</em> sp. var. Dudú by somatic embryogenesis was achieved, as well as the analysis of the genetic integrity of the regenerated material. </p>

STABILITY INDICATING RELATED SUBSTANCES METHOD FOR BISOPROLOL AND CILNIDIPINE IN BULK AND PHARMACEUTICAL DOSING TYPES AND ITS DEGRADENTS WERE CHARACTERISED BY USE OF LC-MS/MS

A reliable, simple yet consistent RP-HPLC method has been developed and verified to combined dosage form of Bisoprolol, Cilnidipine, their relavant substances and characteristic of the degradants by LC-MS/MS. The process used was optimized by using X-Bridge phenyl column (150mmx4.6mm, 3.5 µ) with a gradient elution mode of mobile phase consists of methanol and 0.1% tri ethyl amine of pH-2.5. The developed RP-HPLC method shows strong linearity in the range of concentrations 2-30 µg/ml of Bisoprolol, 4-60 µg/ml of Cilnidipine and 0.1-1.5 µg/ml of Bisoprolol and Cilnidipine impurities. Percentage of regeneration and percentage RSD values were found to be within the allowable limit. The developed method was found to be applicable for routine analysis and utilized for the calculation of both active ingredients and their impurities in tablet dosage form

In Vitro Shoot Regeneration of Lysimachia nummularia L. in Solid and Liquid Culture Medium

Lysimachia nummularia L. is a perennial medicinal and aromatic herb. In this study, the effects of solid and liquid culture environments on micropropagation of L. nummularia were investigated. Nodes were used as an explant type in the experiments. Different combinations of thidiazuron (TDZ: 0.05-0.80 mg L-1) and indole-3-butyric acid (IBA: 0.10 mg L-1) were used as growth regulators in Murashige and Skoog (MS) basal environment. Agar was put in to solidify the solid nutrient media. No agar was put in the liquid environment. In solid and liquid experiments, the most count of shoots was obtained in MS nutrient environment with 0.40 mg L-1 TDZ + 0.10 mg L-1 IBA. The longest shoot was detected in the nutrient environment including 0.05 mg L-1 TDZ + 0.10 mg L-1 IBA in both culture media. The best results for shoot count and percentage of regeneration were determined in the solid nutrient environment according to in vitro propagation values. On the other hand, the best results for shoot length were found in the liquid culture environment. The use of high TDZ in both culture media negatively affected shoot lengths. The regenerated plants were successfully acclimatized to aquatic conditions. The results of this study may help more efficient propagation of L. nummularia by tissue culture.

Development of an Efficient In vitro Regeneration Protocol for Chrysanthemum (Chrysanthemum morifolium Ramat)

An efficient and rapid in vitro regeneration protocol was developed for chrysanthemum (Chrysanthemum morifolium Ramat) using two local varieties of Bangladesh namely, BARI Chrysanthemum-2 (BARI Chry-2) and local yellow (Y). MS medium supplemented with nine different concentrations and combinations of BAP and IAA was employed to optimize regeneration protocol using young in vitro derived leaf explants. Direct organogenesis was observed from the leaf explants on MS medium supplemented with 0.5 mg/l BAP and 2.0 mg/l IAA (T6) for both the varieties. This treatment (T6) induced shoot buds directly on the adaxial surface of the leaf providing the highest regeneration percentage (90% for BARI Chry-2 and 94.73% for Y), the highest number of shoot/explant (7.6 for BARI Chry-2 and 8.6 for Y) and maximum length of the shoot after six weeks (3 cm for BARI Chry-2 and 2.9 cm for Y) of culture. Explants with initially regenerated shoots were subculture on hormone free MS medium for shoot elongation after 4 weeks of their inoculation. During elongation of shoots, 90-95% of the regenerated shoots produced roots spontaneously in hormone free MS medium within 7-8 weeks of their inoculation. Rooted plantlets were transplanted to the field following hardening where 100% plantlets were survived and produced flower without any variation. Plant Tissue Cult. & Biotech. 31(2): 161-171, 2021 (December)

Direct Synthesis of Sulfur-Decorating PAMAM Dendrimer/Mesoporous Silica for Enhanced Hg(II) and Cd(II) Adsorption

Water security caused by heavy metals poses a deleterious hazard to public health and the ecological system. The construction of adsorbents by polyamidoamine (PAMAM) dendrimers for efficient removal of metal ions has attracted considerable interest. However, the general method for the fabrication of these adsorbents was achieved by the surface chemical modification of the substrates with PAMAM dendrimer, which usually causes the defects of low density and uneven distribution of the dendrimer, the blocking of pores, and reducing the adsorption performance. Hence, the development of a new method for preparation of PAMAM dendrimer-based adsorbent to realize the efficient and enhanced adsorption of metal ions is still a challenge. Herein, methylisothiocyanate decorated PAMAM dendrimer/mesoporous silica composites (G0-S-1/x, G1.0-S-1/x, G2.0-S-1/x, x = 2, 4, 6, 8, 10) were synthesized by the direct sol-gel reaction of alkoxysilyl-containing functional PAMAM dendrimer. The adsorbents display enhanced adsorption property for Hg(II) and Cd(II) as compared with the same adsorbents which were prepared by traditional chemical modification method. Take G2.0-S-1/2 as an example, the maximum adsorption capacities are 2.41 and 0.87 mmol·g-1 for Hg(II) and Cd(II), respectively . Moreover, the adsorbents show excellent selective adsorption and regeneration property. G2.0-S-1/2 displays distinct selectivity for Hg(II) with the presence of Co(II), Pb(II), Cd(II), and Cu(II). The regeneration percentage still maintains 95.2% after five adsorption-desorption cycles. The adsorption mechanism is also certified by the experimental method and theoretical calculation.

Expression analysis of OsSERK, OsLEC1 and OsWOX4 genes in rice (Oryza sativa L.) callus during somatic embryo development

Somatic embryogenesis is an asexual reproduction process that occurs in many plant species, including rice. This process contains several totipotency markers such as Somatic Embryogenesis Receptor-like Kinase (SERK), Leafy Cotyledon1 (LEC1) and WUSCHEL-Related Homeobox4 (WOX4) and also a helpful model for embryo development and clones and transformations. Here, we report the gene expression during somatic embryo development correlates with regeneration frequency in 14 Javanica rice (pigmented and non-pigmented) using modifified N6 media supplemented with Kinetin (2.0 mg/L) and NAA (1.0 mg/L). Although there have been advances in understanding the genetic basis of somatic embryogenesis in other varieties, rice is still unexplored, especially during somatic embryo development. Moreover, for the formation of callus induction from immature embryos, 2,4-D (2.0 mg/L, 3.0 mg/L) was used. This study analysed the gene expression of OsSERK, OsWOX4 and OsLEC1 genes through RT-PCR analysis. Higher expression of the OsLEC1 gene indicates that their function may correlate in the in vitro with the high response of rice after transfer to regeneration media. This study found that rice varieties of pigmented rice (MS Pendek and Gogoniti II) and non-pigmented rice (Pandan Ungu) showed high regeneration frequency, showing higher OsLEC1 expression than other varieties because OsLEC1 promotes the maturation of somatic embryos in plant regeneration on day 14. However, the contrast with Genjah nganjuk may be effective because of other regulatory genes. RT-PCR analysis showed OsSERK had less expression level than OsLEC1 and OsWOX4 in the varieties, which correlate with the percentage of plant regeneration, but not for Gogoniti II. In conclusion, the higher percentage of plant regeneration correlates with the higher expression level of OsLEC1 at day 14 of media regeneration of rice.

Natural Regeneration status of conifers along Altitudinal Gradient in Shopain Forest Range of J&K, India

Natural regeneration of conifers is essential for preservation and maintenance of biodiversity. Therefore present study was conducted to study natural regeneration status of conifers in Shopain Forest Range of J&K. To assess the natural regeneration of conifers, at three elevations along altitudinal gradient (Aj, 1800–2100 m amsl; A2, 2100–2400 m amsl; A3, 2400–2700 m amsl), the vegetation analysis was carried out by stratified random sampling. Quadrates of 2 x 2 m were laid at all the three sites. The regeneration status of the tree species was determined for recruits, un-established regeneration, established regeneration and regeneration success was determined. The maximum number of recruits (3521.58/ha), unestablished (1983.33/ha) and established regeneration (600.00/ha) was recorded for Pinus wallichiana at altitude A2 while as the minimum number of recruits (666.67/ha), unestablished (350.00/ha) and established regeneration (100.00/ha) was recorded for Picea smithiana at altitude A3. The maximum regeneration success percent was recorded for Pinus wallichiana at middle altitude with 41.23% and minimum regeneration success was recorded for cedrus deodara at lower altitude with 4.18% The study conducted revealed that maximum regeneration percentage of Pinus wallichiana and Cedrus deodara was recorded at middle altitude while as that of Abies pindrow and Picea smithiana was at upper altitude. The assessment of natural regeneration of conifers also envisaged that Pinus wallichiana has the highest regeneration percentage and Picea smithiana gave the lowest regeneration success percentage.

Shoot regeneration in recalcitrant Indica rice through partial desiccation of callus

Indica rice cultivars are recalcitrant to in vitro manipulations, such as shoot regeneration. The present study was undertaken to induce shoot regeneration through partial desiccation of callus induced from mature seeds of PR 121 indica rice cultivar. Callus was exposed to four partial desiccation treatments i.e. 30 min, 60 min, 90 min and 120 min. The partially desiccation effect was examined in terms of shoot regeneration percentage upon transfer of the desiccated callus to regeneration media. The non-desiccated callus did not show shoot regeneration, whereas 31.50±0.05 percent regeneration was recorded in callus partially desiccated for 60 min. The partial desiccation is likely to be beneficial for inducing shoot regeneration in recalcitrant indica rice cultivars.