• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.171-177
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• 2017

A callus-mediated regeneration protocol for sea-milkwort, an endangered coastal plant species in South Korea, is reported here. The explants of in vitro-plantlets generated from a node culture revealed distinguishable responses in callus induction depending on genotype, explant source, light condition, and 2,4-D concentration. Especially, continuous darkness exclusively facilitated callus induction from explants prior to other treatments. The calli initiated on the media with 2,4-D ranging from 0.1 mg/L to 3.0 mg/L in the dark vigorously proliferated when subcultured on the same media in continuous darkness. Given 1.0 mg/L zeatin in addition to darkness to the calli of the 'Pistachio' genotype, normal adventitious shoots were only regenerated from nodular structures that formed earlier from the calli at the frequency of 24.4 percent. Regenerated shoots easily grew into plantlets with roots and green color on a phytohormone-free MS medium under lighted condition, that were used for node culture as plant materials. Node culture effectively multiplied plantlets in accordance with protocol by Bae et al. (2016). Acclimatized plantlet clusters developed mature plant clusters under inland environment, followed by flowering the following April. Results were merged with node culture protocol suggested by Bae et al. (2016), which, as an in vitro propagation system for sea-milkwort, may contribute to natural habitat restoration.

• Korean Journal of Plant Resources
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• v.21 no.2
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• pp.111-116
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• 2008

This study was carried out to induce plant regeneration via multiple shoot formation from sucker explants of Rubus fruticosus L. ${\times}$ R. parvifolius L. To induce adventitious shoots, the sucker explants were sterilized in 1.2% sodium hypochlorite (NaOCl) solution, and then were cultured on the full and 1/2 MS solid medium supplemented with BA (0.1, 0.5, 1.0, $2.0mg{\cdot}L^{-1}$). After 4 weeks of culture, the highest frequency (83.3%) of shoot formation from sucker explants was obtained from the full MS medium with $1.0mg{\cdot}L^{-1}$ BA. The highest shoot number (3.7) per explant was obtained from the full MS medium with $0.5mg{\cdot}L^{-1}$ BA. After 12 weeks of culture, the number of shoots (15.4) per explant was increased. The highest frequency (95%) of root formation was obtained from the 1/2 MS medium, when the explant with shoot were cultured on the full, 1/2 and 1/4 MS medium. The survival rate of the plantlets after transfer to plastic pots containing sand, soil, and vermiculite (1.1:1, vol.) was 95%. The results indicate that multiple shoot procedure can be applied for an efficient mass propagation of Rubus fruticosus L. ${\times}$ R. parvifolius L.

• Korean Journal of Plant Resources
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• v.27 no.5
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• pp.540-545
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• 2014

The Polygonatum odoratum cv. Gungangbeaksea, bred in Gyeongsangnam-Do Agricutural Research & Extension Service, was cultured in vitro for micropropagate rapidly through the culture of rhizome explants ($5{\times}5mm$). The $7{\times}7mm$ explants of adventitious multi-bud clusters (AMC), obtained through the culture of rhizome explants (MS + 3.0 mg/L BA) were cultured on MS media with BA and TDZ. The shoot multiplication was favorable on the MS medium containing 3.0 mg/L TDZ with 2.8 in shoot number. But the formation of AMC was low in all media tested. The explants of AMC were cultured on MS media containing 1.0~5.0 mg/L TDZ and NAA to multiplicate AMC more. The formation of AMC was a little more stimulated on combined MS media of TDZ and NAA, than that with TDZ alone. The multiplication of shoots and AMC was favorable on MS media with 3.0 mg/L TDZ and 5.0 mg/L NAA, and 5.0 mg/L TDZ and 3.0 mg/L NAA. As the concentration of MS salts increased, the formation of AMC was decreased. But the formation of AMC was more stimulated, as the concentration of sucrose increased to 7%. Therefore, the multiplication of shoots and AMC was suitable on media containing 3.0~5.0 mg/L TDZ and NAA, and 7% of sucrose. The explants of AMC were rooted on media with 3.0 mg/L IBA, or 2.0 mg/L NAA with more than 80% in rooting ratio. The plantlets were treated at $5^{\circ}C$ for 8 weeks, and cultured ex vitro for 8 weeks. The survival ratio of plantlets were 100% in vermiculite, and the mixed soil with perlite 1 volumn and vermiculite 1 volumn.

• Korean Journal of Plant Tissue Culture
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• v.24 no.3
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• pp.129-135
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• 1997

Morphogenetic responses were investigated by culturing embryo and leaf explants of Korean wild type tea plant, Camellia sinensis (L.) O. Kuntze. Induction of direct somatic embryogenesis as well as adventitious and/or axillary shoots was obtained from mature zygotic embryo cultures on Murashige and Skoog (MS) basal medium having 5 to $20\mu\textrm{M}$cytokinin a lone. Morphogenetic response was decreased dramatically by the addition of auxins tested. One hundred percent of induced and isolated shoots formed roots after four weeks of culture on half-strength MS or quarter-strength Schenk and Hildebrandt (SH) media supplemented with $10\mu\textrm{M}$indole-3-butyric acid (IBA). Immature zygotic embryos were shown to be a suitable explant for embryogenic callus formation in the presence of 2, 4-dichlorophenoxyacetic acid(2, 4-D) in basal medium. Mature zygotic embryo originated leaves were used to test their ability for mophogenesis by incorporating plant growth regulators such as IBA, naphthyl-1-acetic acid (NAA), and 6-benzylaminopurine (BAP). Apparently, the morphogenetic responses of the cultured explant sources on the types and/or levels of plant growth regulators tested were observed visually.

• Journal of Plant Biotechnology
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• v.50
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• pp.176-182
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• 2023

Plant regeneration protocols for adventitious shoot organogenesis from apple (Malus domestica 'Fuji') leaf explants were developed in the present study. The effects of dark incubation periods in the early stages of culture, pre-treatment methods, the number of explants per culture container, the type of culture containers, and the orientation of the explants on culture media were evaluated to determine the optimal shoot regeneration conditions for 'Fuji' apple leaf explants. Light incubation of explants produced minimal response. However, dark incubation of explants for 4 weeks during the initial culture period enhanced shoot regeneration frequency. Comparing the number of explants per container, a higher percentage of shoot regeneration was obtained with nine explants per container compared with four explants per container. Pre-treatment, before culture, by dipping explants in a liquid regeneration medium containing 40 g/L of sorbitol for 2 hours produced the highest shoot formation rate, and the time of shoot formation was accelerated. The percentage of shoot regeneration and number of shoots per regenerating explant reached a maximum of 87.5% and 4.7, respectively. The regenerated shoots were elongated and rooted on a rooting medium of 1/4 MS with 0.2 mg/L IBA. The plantlets were successfully acclimatized, and the regenerated plants produced normal phenotypes.

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.271-275
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• 2007

In the chloroplast transformation process, a chloroplast containing transformed chloroplast genome copies should be selected over wild-type chloroplasts on selection medium. It is more effective for a cell to become homoplasmic if the cell contains smaller number of chloroplasts. Therefore, to reduce the number of chloroplasts in mesophyll cells in tobacco, we overexpressed FtsZ to generate transgenic plants, of which mesophyll cell contained a few enlarged chloroplasts contrast to a wild-type mesophyll cell containing approximately 100 chloroplasts. It was demonstrated that transgenic leaf tissues comprising cells with a few enlarged chloroplasts gave rise to approximately 40% higher frequency of chloroplast-transformed adventitious shoots.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.203-207
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• 2004

To establish high frequency shoot formation from two cultivars (Cheongyangjaerae and Myungan) of boxthorn (Lycium chinense Mill.), hypocotyl segments with cotyledons from seedlings were used as explants. High frequency adventitious shoot formation (more than 80%) were obtained from hypocotyl segments with cotyledon on MS medium supplemented with 1.0 mg/L zeatin, when precultured for 3 weeks under dark conditions followed by transfer to light conditions. But there was no shoot induction in the explants cultured without preculture under dark conditions. Roots were induced from the shoots when transferred to rooting medium supplemented with 1.0 mg/L IAA for 4 weeks. Regenerated plantlets were grown to normal mature plants in soil.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.308-314
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• 2006

This experiment was conducted out to investigate the effect of plant growth regulators on callus and shoot formation. The callus formation was effective on 1/2 MS medium containing 2,4-D, while shoot formation was suppressed. Shoot formation and differentiation were the highest in combination 0.1 mg/L of IAA and 0.1 mg/L of BA. The polarity of explants was investigated from cotyledon, which excised 20% of each basal and terminal parts. Formation of shoot was induced from excised ends of the basal part. In excised ends of the basal part, callus was induced vigorously and shoots were produced lately. Root induction was easily achieved in 1/3 MS medium from the adventitious shoot and more than 90% of regenerated plantlets acclimatized successfully and flowered normally.

• Korean Journal of Plant Resources
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• v.17 no.1
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• pp.28-33
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• 2004

This study was conducted to simple transformants selection by herbicide Basta treatment after transformation with Agrobacteium tumefaciens MP90/PAT in hybrid poplar(Populus alba ${\times}$ P. glandulosa No. 3). In preliminary study, we determined that the lethal concentration of herbicide Basta was 1.0mg/L in callus culture, adventitious bud formation and axillary bud elongation experiment. By the treatment of 1.0mg/L Basta, we could be selected the transformed shoots effectively from the various cultures. In addition, the treatment was useful on selection of transformants which are growing in soil pot. Finally, we also confirmed the transformation by PAT assay, Above results show that the herbicide Basta treatment and PAT assay can be a very simple and effective method for the identification of PAT gene transformed hybrid poplar.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.449-455
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• 2010

'Moulinrouge' was selected as the best regenerating cultivar among 18 different spray-type chrysanthemum cultivars bred in the Gyeongnam Flowers Breeding Research Institute. When the leaf explants from standard- and spray-type chrysanthemum 'Jinba' and 'Moulinrouge' were incubated on MS basal medium supplemented with $0.5mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA, both 'Jinba' and 'Moulinrouge' induced adventitious shoots that can be regenerated into plantlets. Based on these regeneration conditions, we developed an efficient $Agrobacterium$-mediated chrysanthemum 'Moulinrouge' transformation method by using sequential selection of shoots from low ($10mg{\cdot}L^{-1}$) to high ($30mg{\cdot}L^{-1}$) concentrations of kanamycin after co-cultivation of leaf explants with $Agrobacterium$ for 10 days and induction of shoots. All kanamycin resistant plants investigated with genomic PCR analysis carried the report gene, $AtSICKLE$, in their genome. Although expression levels of the report gene in the transgenic plants investigated with RT-PCR were relatively low because of inefficiency of CaMV 35S promoter in chrysanthemum, transgenic lines expressing $AtSICKLE$ efficiently showed leaf epinasty phenotype. We expect that our results will provide a useful method that can perform a high-throughput investigation of genes isolated and studied well in model plants for molecular breeding of chrysanthemum.