• Journal of Sericultural and Entomological Science
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• v.30 no.2
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• pp.75-83
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• 1988

These experiments were carried out to define the rest period of mulberry by treating growth regulators in Taegu, Korea. Results obtained were as follows: It was recognized that the depth of rest in Taegu, Korea, was not deeper than that in Tokyo and Kagoshima, Japan. The rest of mulberry was begun at the end of September, subsequently became deeper through the first October into the late October and then turned gradually into quiescence by the beginning of November. Buds sprayed by gibberellic acid ($GA_3$) 10ppm and urea 0.5% were promoted to sprout, while naphthalene acetic acid (NAA) 0.02% inhibited strongly bud sprouting and abscisic acid (ABA) 20ppm had no effect on the rest of mulberry. Gibberellic acid 10ppm enhanced the rate of green color of bud after incubation for 10 days at $30^{\circ}C$. By the portion of mulberry stems, the depth of rest was different that the middle buds were less dormant than those lower. The optimal time required for the mulberry winter bud break is 15 days incubation at $30^{\circ}C$ as treated with $GA_3$.

• Journal of Plant Biotechnology
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• v.37 no.2
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• pp.228-235
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• 2010

The establishment of cell suspension culture and plant regeneration of the halophytic Leymus chinensis (Trin.) are described in this study for the first time. Callus induction solid medium containing Murashige and Shoog (MS) basic salt, $2.0\;mg\;l^{-1}$ 2,4-dichlorophenoxyacetic acid (2,4-D), and $5.0\;mg\;l^{-1}$ L-glutamic acid with $30.0\;g\;l^{-1}$ sucrose and $4.0\;g\;l^{-1}$ gelrite for solidification induced the highest rate of cell division in Type 1 callus among calli of various types. Liquid medium with the same hormone distribution was therefore, used for cell suspension culture from Type 1 callus. Over a 30 d suspension culture at 100 rpm, great amounts of biomass were accumulated, with 71.07% average daily increment and 22.32-fold total fresh weight increment. Comparison of before and after suspension culture, the distribution of different size callus pieces and the maintenance of callus type were basically unaltered, but a slight increase in relative water contents was observed. To induce the potential of plant regeneration, the directly transferring on plant regeneration solid medium containing MS basic salt, $0.2\;mg\;l^{-1}$ $\alpha$-naphthalene acetic acid (NAA), $2.0\;mg\;l^{-1}$ kinetin (Kn), and $2.0\;g\;l^{-1}$ casamino acid and indirectly transferring were simultaneously performed. Even now growth rates of suspension-derived callus on solid medium were approximately half of those of Type 1 callus, but faster somatic embryogenesis was observed. Rooting of all regenerated shoots was successfully performed on half-strength MS medium. All plants appeared phenotypically normal.

• Korean Journal of Medicinal Crop Science
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• v.20 no.6
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• pp.479-486
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• 2012

The production of adventitious roots derived from root explant of Echinacea angustifolia and its secondary metabolite content were assessed in different types and levels of auxin. The induction of adventitious roots from root explant cultured in Murashige and Skoog solid medium supplemented with 1.0 mg/L indole -3-butyric acid (IBA) attained highest as 20.87 mg fresh weight and 3.07 mg dry weight per culture but root suspension culture at the same concentration of IBA enhanced biomass production as 3.07 g fresh weight and 0.38 g per culture after 4 weeks in culture. 3.0 mg/L ${\alpha}$-naphthalene acetic acid (NAA) treatment had similar effect on root biomass production as 3.07 g fresh weight and 0.38 g per culture with liquid suspension culture, whereas adventitious roots exposed to over 3.0-5.0 mg/L IBA or 5.0 mg/L NAA were less responsive by reducing the number of adventitious roots and/or changing root morphology such as short and thick. The content of secondary metabolites such as phenolic, flavonoids and total caffeic acid in adventitious roots cultured on MS medium supplemented with 1.0 mg/L IBA were attained highest as 27.20, 9.60. 10.67 mg/g dry weight, respectively. Overall, the best production of root biomass and secondary metabolites were given by 1.0 mg/L IBA.

• Journal of Plant Biotechnology
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• v.39 no.1
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• pp.69-74
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• 2012

Using calli of $Muscari$ $armeniacum$ cv. 'Early Giant' that is monocotyledonous ornamental bulb crop with increasing demand in Korea, we carried out current studies to establish an in vitro multiple propagation protocol via somatic embryogenesis. We found that soft pale yellow green calli were induced from leaf explants cultured on all media containing 0.1~3.0 $mg{\cdot}L^{-1}$ auxins such as 1-naphthalene acetic acid (NAA) and 2,4-dichlorophenoxyacetic acid (2,4-D). However, induced calli showed vigorous growth only when they further transferred on same media containing 2,4-D, 4-amino-3,5,6-tri-chloropicolinic acid (picloram), or 3,6-dichloro-o-anisic acid (dicamba). Although frequency of somatic embryo induction depended on callus source and PGR composition in somatic embryo induction media, somatic embryogenesis was initiated on surface of proliferated calli after transferring on media with no PGR or 0.01 $mg{\cdot}L^{-1}$ NAA co-supplemented with various cytokinins such as $N^6$-benzylaminopurine (BAP). Highest number of embryo at 9.3 per callus clump was obtained when calli which were grown under 0.1 $mg{\cdot}L^{-1}$ picloram supplementation were sub-cultured on medium with 0.01 $mg{\cdot}L^{-1}$ NAA and 0.5 $mg{\cdot}L^{-1}$ BAP. In addition, morphological characteristics of somatic embryo were categorized into following nine phases: globular, biased heart, biased torpedo, early cotyledonary, middle cotyledonary, late cotyledonary, early sprouting, middle sprouting, and late sprouting embryos.

• Plant Biotechnology Reports
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• v.4 no.2
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• pp.129-138
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• 2010

An efficient transformation system for high-throughput functional genomic studies of kiwifruit has been developed to overcome the problem of necrosis in Actinidia arguta explants. The system uses Agrobacterium tumefaciens strain EHA105 harbouring the binary vector pART27-10 to inoculate leaf strips. The vector contains neomycin phosphotransferase (nptII) and ${\beta}$-glucuronidase (GUS) (uidA) genes. A range of light intensities and different strengths of Murashige and Skoog (MS) basal salt media was used to overcome the problem of browning and/or necrosis of explants and calli. Callus browning was significantly reduced, resulting in regenerated adventitious shoots when the MS basal salt concentration in the culture medium was reduced to half-strength at low light intensity ($3.4\;{\mu}mol\;m^{-2}\;s^{-1}$) conditions. Inoculated leaf strips produced putative transformed shoots of Actinidia arguta on half-MS basal salt medium supplemented with 3.0 $mg\;l^{-1}$ zeatin, 0.5 $mg\;l^{-1}$ 6-benzyladenine, 0.05 $mg\;l^{-1}$ naphthalene acetic acid, 150 $mg\;l^{-1}$ kanamycin and 300 $mg\;l^{-1}$ $Timentin^{(R)}$. All regenerated plantlets were deemed putativ transgenic by histochemical GUS assay and polymerase chain-reaction analysis.

• Plant Biotechnology Reports
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• v.2 no.3
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• pp.213-218
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• 2008

Swertia chirata is an endangered gentian species that prefers to grow at higher altitudes. This ethnomedicinal herb is known primarily for its bitter taste caused by the presence of important phytochemicals that are directly associated with human health benefits. Due to a continuous loss of habitat and inherent problems of seed viability and seed germination, alternative strategies for propagation and conservation are urgently required to prevent the possible extinction of this species. We have formulated a reproducible protocol for the rapid propagation and conservation of this plant using leaves taken from in vitro shoot cultures. Direct induction of more than seven shoot buds per explant was achieved for the first time when the explants were placed on MS medium supplemented with $2.22{\mu}M$ N-6-benzyladenine, $11.6{\mu}M$ kinetin, and $0.5{\mu}M$ ${\alpha}-naphthalene$ acetic acid. Direct organogenesis was noted exclusively from the adaxial surface of the basal segments of leaves. Leaves closer to the apical meristem were more responsive than those farther away from the meristem. Plants raised through direct organogenesis were evaluated for their clonal fidelity by chromosomal analysis and DNA fingerprinting. Complete plants were successfully transferred to the field condition and produced viable seeds. Given the enormous potential of this age-old medicinal plant in terms of potential health-benefitting drugs, this protocol can be used for commercial propagation purposes and to initiate future genetic improvement studies.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.135-141
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• 2005

Protocols for in vitro conservation was developed for Coleus forskohlii. Plants maintained both in field served as explant source. Shoot tips and single node cuttings were used to optimize protocols for in vitro multiplication. MS basal medium supplemented with $0.54\;{\mu}M$ naphthalene acetic acid (NAA) and $8.87\;{\mu}M$ benzy-ladenine (BA) induced multiple shoots in shoot tips and nodes. Shoot multiplication was amplified with a gradual decrease of BA concentration, leading to its final omission after 4 months. Concomitant rooting on multiplication media enabled successful establishment extra vitrum. For in vitro conservation studies, experiments were carried out with 2-3 week maintained in vitro plants under standard and reduced culture conditions (SCC, RCC). In vitro plants could be successfully conserved in full strength MS medium (FMS) under SCC for 6 months without subculture with full potential to regenerate, producing viable shoots and nodes. The root production remained unaffected due to conservation, showing high rooting activity in mannitol and low temperature treatments. Preset low temperature (15 and $10^{\circ}C$) and reduction in media constituents does not appear to favour conservation, although the former accomplished conservation levels equal to (FMS) under SCC.

• Advances in Traditional Medicine
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• v.7 no.2
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• pp.197-204
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• 2007

The present study focused on the establishment of micropropagation protocol for the high value Pluchea (P.) indica (L.) Less., genotype, an important medicinal plant and evaluation of the diuretic activity of the leaf extract of the tissue cultured plant. Leaf explants, nodal segments and shoot tips were cultured in MS medium supplemented with auxin and cytokinin and their combinations. With the objective of inducing callus giving rise to new adult plants, naphthalene acetic acid was found to be most effective for (80%) for callus induction. The methanolic extract of leaves of the micropropagated P. indica was investigated for its diuretic activity in Wistar albino rats. Urinary excretion parameters were studied for evaluation of diuretic activity using Frusemide (20 mg/kg, p.o.) as standard. The extract showed significant diuretic activity at the doses of 100, 200 and 300 mg/kg. p.o. An oral acute toxicity study for the extract was carried out and the $LD_{50}$ value was found to be 2,825 mg/kg body weight.

• Journal of Plant Biotechnology
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• v.36 no.3
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• pp.236-243
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• 2009

The halophyte Leymus chinensis (Trin.) is a perennial rhizome grass (tribe Gramineae) that is widely distributed throughout China, Mongolia and Siberia. This study was conducted to investigate an optimal condition for plant regeneration from mature seeds, leaf base segments, and root segments in L. chinensis. Plant growth regulators affecting embryogenic callus induction and plant regeneration were investigated by four-factor-three-level [L9 (34)] orthogonal test in this study. The effects of explants types (mature seeds, leaf base segments and root segments), callus types, medium types were examined in this study. Wild type (WT) and Jisheng No. 1 plants (JS) were used for primary callus induction. A clear explants difference was seen during callus induction; mature seeds were considered as the preferred explants; and the highest frequency of callus induction was obtained in Medium 6 using mature seeds as explants in WT. Plant regeneration ability was evaluated by frequencies of green callus forming, shooting, rooting, and shooting with roots. Effect of α-naphthalene acetic acid (NAA) on shoot regeneration was remarkable with the highest frequency of 70.8% in WT after 2-month culture. The medium with 0.2- 0.5 mg/L NAA was found to have the highest shoot induction. All regenerated shoots were successfully rooted when transferred on half-strength Murashige and Skoog (MS) basal medium. The acclimatized plantlets were grown to mature with flowering and seeds setting in green house conditions.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.62-62
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• 2022

Freesia has been an important worldwide cut flower because of its fragrance, long vase life and the wide color range of the flower. The conventional propagation methods by seeds and corms have many disadvantages such as shorter inflorescences with fewer numbers of florets, a reduction in cut flower quality and the accumulation of plant viruses in corms by successive cultivation. Therefore, the conventional propagation systems in Freesia needs to be replaced with tissue cultures to overcome the disadvantages. This study explored an efficient multiplication protocol using the combination of plant growth regulators (PGRs) for developed cultivar 'Sunny Gold'. The combination between 6-benzylaminopurin (BA) and α-naphthalene acetic acid (NAA) did not produce new shoots but developed enlarged roots. BA only treatments and the combination between BA and kinetin treatments were effective on shoot multiplication. The highest average number of shoots was 5.3 in the presence of 3 mg/L BA and 0.5 mg/L kinetin. To produce corms and cormlets, proliferated shoots were subcultured on 1/2 Murashige and Skoog (MS) medium supplemented with 90 g/L sucrose, 1 g/L charcoal and 7 g/L plant agar and placed at 4℃ in the dark for 6 months. The small size of corms and comlets were produced. The average number of regenerated comlets was 2.75 per shoot. The results showed that shoot multiplication is more efficient than cormlet regeneration for in vitro freesia proliferation.