• Korean Journal of Medicinal Crop Science
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• v.4 no.2
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• pp.132-138
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• 1996

This experiment was carried out to establish a year-round production system of pathogen-free stock through micropropagation in Fritillaria thunbergii as medicinal bulbous plant. The effect of different types of culture method and plant growth regulators, activated charcoal and mannitol on bulblet formation and subsequent growth were investigated. The MS solid medium containing 1. 0 mg/L kinetin and 0. 3 mg/L NAA was effective on bulblet formation and propagation rate compared to liquid and suspension culture. Addition of activated charcoal at 0. 01% to 0. 1% in the medium promoted bulbing of cultured bulblets and shoot formation. Addition of 1% to 2% mainnitol in MS medium was effective on the formation of bulblet and subsequent growth of bulblets compared to control. In addition of inhibitors, $10{\sim}100\;mg/L$ B-9 and Chloromequat had effective to stimulate bulblet growth but their effects were not so much as mannitol treatment. ABA treatment had detrimental effect on survival rate of explant and bulblet formation.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.1-6
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• 1994

Cotyledonary and hypocotyl explants of melon seedlings were cultured on Murashige and Skoog's (MS) medium supplemented with various concentrations of 2,4-Dichlorophenoxyacetic acid (2,4-D) and benzyladenine (B.A).Up to 22% of cotyledonary explants and 7%, of hypocotyl explants, respectively: Produced somatic embryos through intervening two types of calli: bright yellow compact (BYC) callus and pale-yellow compact (PYC) callus. BYC callus was capable of producing somatic embryos at initial culture, but it became necrotic as subrulhues proceeded. In contrast UC callus was incapable of producing somatic embryos during initial culture (first 6 weeks), but it became bright-yellow friable (BYF) callus with forming a few globular embryos after 2 months of subculture, indicating that the callus turned embryogenic. The embryogenic capacity of BYF maintained for over one year when the callus was sucultured at 4-week interval. Upon transfer onto MS basal medium the callus gave rise to numerous somatic embryos and subsequently converted to plantlets. Plantlets were transplanted to potting soil and grown to maturity in the phyotron.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.275-280
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• 2009

Direct shoot regeneration from leaf or internode or petiole segments was conducted in 33 cultivars of chrysanthemum. Shoot regeneration rates varied according to cultivars, culture media, and explant types. The high shoot regeneration rate of more than 70% in 15 cultivars (‘Pink Pangpang’, ‘Orange Memory’, ‘Relance’, ‘Zinba’, ‘Beakma’, ‘Innocence’, ‘Sunny Pangpang’, ‘Euro Yellow’, ‘Dublin’, ‘Boramae’, ‘Peak’, ‘Euro White’, ‘Vesuvio White’, ‘Linneker Salmon’ and ‘Pink Pride’) and 2 ones (‘Forward’ and ‘Agason’) was obtained from the segments of leaves and internodes, respectively, cultured on MS medium containing 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 30 g-$L^{-1}$ sucrose. That in 6 cultivars (‘Shuhonochikara’, ‘Hakunosen’, ‘Whitney Pangpang’, ‘Plaisir D’Amour’, ‘Grace’ and ‘Kumsu’) was observed from the segments of leaves or internodes cultured on 1/2 MS medium 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 15 g-$L^{-1}$ sucrose In case of 3 cultivars (‘Ilweol’, ‘Puma White’ and ‘Sharon’), when internode explants excised from mother plants, which were pre-cultured on MS medium containing 2 g-$L^{-1}$ activated charcoal and 30 g-$L^{-1}$ sucrose for two months in the dark, and cultured on MS medium containing 1.0 mg-$L^{-1}$ BAP, 0.5 mg-$L^{-1}$ IAA and 30 g-$L^{-1}$ sucrose, that was shown. Seven cultivars including ‘Puma Yellow’, ‘Argus’, ‘Yes Morning’, ‘Whiparam’, ‘Hakunohikari’, ‘Charming Eye’ and ‘Moon light’ requires more improved culture conditions. Tissues with the highest shoot regeneration rate were in descending order, leaf, petiole, and internode segments.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.178-182
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• 2007

Rauvolfia serpentina (L.) Benth. ex Kurz is a medicinal plant and an endangered tropical rainforest plant species. Since the field cultivation that aims to fulfill the industrial needs is never accomplished, tissue culture appears to be the most feasible way to improve the quality and quantity of R. serpentina. This experiment used two kinds of explants (roots and shoots) to induce optimal root formation in different combinations of auxin and photoperiod. Each explants exhibited different responses on given treatments. Differentiated root could be produced from explants cultured in IBA 20 mg/L with and without light. The highest number of roots, root length and root weight induced from shoot explants were effective on MS medium containing IBA 20 mg/L and incubated under dark condition, while highest total weight (callus and root) from root explants cultured on MS medium supplemented 10 mg/L IBA and 10 mg/L NAA and incubated under day length (11/13 hr). The root induced from shoot explants produced the highest major alkaloid content. The highest content of ajmaline (2.17 ppm fresh weight) and reserpine (1.30 ppm fresh weight) were observed in shoot explants cultured in MS medium containing combination of IBA 10 mg/L and NAA 10 mg/L and incubated under dark condition, yohimbine (1.47 ppm fresh weight) was in the shoot explants cultured in MS medium containing NAA 20 mg/L and incubated under day length, while serpentine was absent.

• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.15-18
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• 2002

Callus and shoot formation of leaf explants from in vitro propagated shoots and field grown plants depending on the position of leaf, and four boxthron cultivars were investigated. Callus formation of explants from both in vitro shoot and field grown plants as easily achieved at the cut surfaces of explants but the callus formed from leaf of in vitro shoots was hardened as the duration of culture was proceed. Calli were effectively induced from leaves detached from the middle position of both in vitro and in vitro plants on MS medium containing 0.5 mg/L NAA with 0.2 mg/L BA, and the growth of calli were better in field grown leaves than in vitro grown leaves. Shoot formation were effectively induced from leaves detached from the upper position in vitro plants, and the middle parts of in vitro plants on MS medium containing 0.01 mg/L (NAA with 0.2 mg/ BA. There was difference on the frequency of shoot formation among four different cultivars; 'Jindojaerae' was the best for shoot formation followed by 'Cheonyang', 'Younghagukija' and 'Cheongyangjaerae'.

• Plant Biotechnology Reports
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• v.5 no.4
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• pp.345-352
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• 2011

The rheological and diffusion properties of blends of agar/guar gum, agar/Phytagel and Phytagel/guar gum were analysed and compared to those properties of agar or Phytagel applied alone at two different gelling concentrations. Moreover, their effects on the shoot multiplication of the apple scion Galaxy and two black locust clones (SF63, SF82) were studied, and their cost benefits over agar were calculated. Elastic hydrogel formation was demonstrated for each blend by rheological measurements, but the gel strength depended on the types and concentrations of the applied gelling agents and blends. Guar gum was able to speed the diffusion in the different blends, and diffusion was independent of gel strength. The rate of shoot multiplication increased (to 8.9 shoots per explant) and the percent of hyperhydrated shoots decreased (to 12%) when the blend of agar/guar gum was used for the shoot multiplication of apple. Similarly, the highest multiplication rates of black locust clones (between 3.9 and 4.1) were obtained on media solidified by blends containing guar gum. The best shoot performance with the lowest percent of hyperhydrated shoots (11-12% in SF63 and 2-23% in SF82) was achieved using agar alone or the agar/guar gum blend. The shoot multiplication was improved of both species and the production cost was reduced by 42% by using the agar/guar gum blend.

• Journal of Plant Biotechnology
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• v.41 no.4
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• pp.236-241
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• 2014

An efficient regeneration protocol for stem disc culture of Populus euramericana, which is important species for bioenergy resource in agroforestry, was established. The number of explants that were obtained and the number of explants that regenerated varied with the genotypes. However, in all the genotypes, stem disc culture produced more regenerated shoots than did in axillary bud culture. A comparison of the effects of cytokinin type and concentration on shoot regeneration in different explants (i.e., petiole, leaf, and root segments of P. euramericana) revealed that a concentration of $0.002mg\;l^{-1}$ thidiazuron (TDZ) used on petiole segments resulted in the greatest shoot regeneration (95.83%). The hormonal requirements for the greatest shoot regeneration in the three explant types varied. Different concentrations of $AgNO_3$ and $CoCl_2$ were added separately to the medium to stop the yellowing and subsequent necrosis of the regenerated shoots. Lower concentrations (3 and $5mg\;l^{-1}$) of these compounds improved shoot regeneration and elongation, compared with the control. The in vitro-regenerated shoots were transferred to rooting medium and subsequently acclimatized. The highly efficient regeneration system of P. euramericana reported here can be used for mass propagation of this recalcitrant for regeneration, economically important tree species.

• Journal of Plant Biotechnology
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• v.41 no.2
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• pp.100-106
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• 2014

In order to develop an efficient in vitro micropropagation technique for a rare plant species, Astragalus membranaceus Bunge var. alpinus N., shoot proliferation and in vitro or in vivo rootings were conducted and hyperhydrated leaf generated from cultures was histologically observed. During shoot induction, no distinct effect on multiple shoot induction was found between BA and kinetin treatment. BA enhanced the number of internodes, whereas kinetin stimulated shoot elongation. Hyperhydrated leaf composed of bigger cells and retarded palisade parenchyma and showed irregular cell arrangement compared to normal leaf. Especially starch content in hyperhydrated leaf was significantly reduced. The best rooting rate was achieved by B5 medium among three different medium (B5, MS and WPM) and 0.1mg/L IBA treatment induced the highest rooting ratio (80%). No statistical difference was induced by explant types (apical bud or axillary bud) in terms of rooting ratio. In vivo cutting induced rooting rate up to 65% by 0.5% IBA/Talc powder treatment. Although in vivo rooting rate was less efficient compared to in vitro rooting, better survival rate was observed after soil acclimatization. Present study suggested that above micropropagation techniques can be used for rapid multiplication as well as in vitro or in vivo conservation of the species.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.1
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• pp.26-34
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• 2009

Porcine embryonic stem (ES) cells have a great potential as tools for transgenic animal production and studies of regulation of differentiation genes. Although several studies showed successful derivation of porcine ES-like cells, these cells were not maintained long-term in culture. Therefore, this study was conducted to establish porcine pluripotent ES-like cells using in vivo fertilized embryos and to maintain these cells in long term culture. Porcine ES-like cells from in vivo embryos obtained by immunosurgery or whole explant culture were successfully cultured for over 56 passages. Morphology of porcine ES-like cells was flat-shaped with a monolayer type colony. These cells stained for alkaline phosphatase throughout the culture. Furthermore, porcine ES-like cells reacted with antibodies against Oct-4, SSEA-1, SSEA-4, Tra-1-60, and Tra-1-81, which are typical markers of undifferentiated stem cells. To characterize the ability of porcine ES-like cells to differentiate into three germ layers, embryoid body formation was induced. After plating of these cells, porcine ES-like cells were spontaneously differentiated into various cell types of all three germ layers. In addition, porcine ES-like cells were successfully derived from IVF blastocysts in media containing human recombinant basic fibroblast growth factor.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.37-45
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• 2007

The genetic transformation of watermelon by Agrobacterium has been known very difficult and a few successful cases have been reported by obtaining the direct shoot formation. However, since this direct shoot formation is not guaranteed the stable transformation, the stable transformation with reproducibility is required by a different approach such as a callus induced manner. The best conditions for inducing the callus from cotyledon and root explants of watermelon were 2 mg/L zeatin + 0.1 mg/L IAA and 2 mg/L BA + 0.1 mg/L 2,4-D, respectively. The GFP expression in the callus was identified and monitored through fluorescent microscopy after transformation with pmGFP5-ER vector. Paromomycin rather than kanamycin was used for selecting the nptll gene expression because it was more effective to select the watermelon explants. Four different callus types were observed and the solid green callus showed stronger GFP expression. The highest frequency of GFP expression in the callus developed from cotyledon was 9.0% (WM8 inbred line), while the highest frequency from root was 8.3% (WM6 inbred line). The WMV-CP was transformed using the method of GFP transformation and the genetic transformation of WMV-CP was confirmed by PCR and Southern blot analysis. Here we present a system for callus induction of watermelon explant and the callus induced method would facilitate the establishment of stable watermelon transformation.