• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.21-24
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• 2001

Peucedanum japonicum $T_{HUNB}$ used as a edible and medicinal plants was investigated for in uitro regeneration. Callus formation occurred on leaf and stem explant cultures and showed spontaneous embryogenic and organogenic capability on MS basal medium supplemented with 0.1~5 mg/L NAA and 0~10 mg/L BA in dark. The regeneration was highest on the condition supplemented with 2.5 mg/L NAA and 10 mg/L BA. Development of the somatic embryo progressed through the globular, heart-shaped, torpedo-shaped and cotyledonary stage, typical of zygotic embryos. When the first somatic embryos was cultured on the medium supplemented with 0.2 mg/L NAA, secondary somatic embryo were induced with higher frequency on the hypocotyl then on the cotyledon and root.t.

• Korean Journal of Plant Tissue Culture
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• v.21 no.3
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• pp.167-171
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• 1994

This study was carried out to investigate the possibility of plant regeneration through somatic embryogenesis in suspension culture of Aralia elata S. Callus was induced from the explants of leaf and petiole cultured in the MS media containing 2,4-D and TDZ. More embryogenic calli were formed from petiole and with combination treatment of 24-D and TDZ. The quarter strength MS medium was effective for increasing number of somatic embryos. Mannitol supplemented to the quarter strength MS medium, reduced somatic embryo formation but inositol increased. Normal plantlets(86%) were regenerated from mature somatic embryos in MS basal medium and 50% of those survied when transplanted to the vermiculite in greenhouse.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.241-246
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• 2002

Somatic embryos or adventitious buds were formed from the segments of zygotic embryo of Lycium chinense Mill. on Murashige and Skoog (MS) medium supplemented with auxins (2,4-D, NAA, IAA) and / or cytokinins (zeatin, kinetin, BAP). Embryogenic callus formed on MS medium containing 0.5 mg/L 2,4-D and then differentiated into somatic embryos without transfer to hormone free medium. On the other hand, adventitious buds were formed on medium with 0.01 mg/L 2,4-D and 0.5 mg/L zeatin. Among various parts of zygotic embryos, the morphogenic potential was higher in the cotyledonary region, and the most organogenic potential was found in cotyledon followed by radicle, hypocotyl, and whole embryo. Histologically, bipolar structure of the heart-shaped embryos were confirmed and in adventitious buds only shoot apical meristems were found to exist.

• Journal of Plant Biotechnology
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• v.29 no.4
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• pp.253-257
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• 2002

To establish the optimum condition for plant regeneration from somatic embryos of Acanthopanax sessiliflorus Rupr. et Maxim, a medicinal plant, somatic embryos were induced from zygotic embryo-derived embryogenic callus in hormoen-free MS medium. To induce plantlet conversion, cotyledonary somatic embryos were cultured on MS solid medium with GA$_3$at various concentrations (0~10 mg/L) for three weeks. Plantlets were transferred to 1/3 MS solid medium with 0.5% charcoal for 7 weeks. Stem length was increased proportionally to the concentration and treatment period of GA$_3$. Also, the highest leaf width (8.9 mm) and leaf number (2.84) of plantlet were obtained when plantlets were converted on 5,10 mg/L GA$_3$pretreatments, respectively. The highest plant conversion frequency (66.7%) was obtained when the somatic embryos were cultured on medium containing 5 mg/L GA$_3$ for 3 weeks and then were transferred to 1/3 MS medium with 0.5% charcoal. The highest survival rate of soil transfer was 90% when plantlets were regenerated on medium with 5 mg/L GA$_3$ for 3 weeks and then transferred to plastic pots containing vermiculite and sand mixture for 4 weeks.

• Journal of Plant Biotechnology
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• v.31 no.2
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• pp.121-126
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• 2004

Bleeding heart (Dicentra spectabilis L. Lemaire) is one of the most valuable wild flower in Korea. This work was conducted for the mass production of somatic embryos through suspension culture and more effective plant regeneration system in Dicentra spectabilis. High-frequency embryogenic callus proliferation was achieved in SH liquid medium supplemented with 1 mg/L 2,4-D. Half-strength SH medium was suitable concentration for somatic embryo induction and germination. About 5,000 embryos were produced per 250$m\ell$ flask after 4 weeks of culture. Germination rate of somatic embryos was decreased when GA$_3$ was added in medium. The plantlets showed a 58％ survival rate when transferred to pots after 1 month of culture. The results indicate that micropropagation procedure via somatic embryogenesis can be applied for an efficient mass propagation of Dicentra spectabilis.

• Korean Journal of Plant Tissue Culture
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• v.25 no.5
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• pp.329-333
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• 1998

$\beta$-Glucuronidase (GUS) gene of Escherichia coli was introduced into sweet potato (Ipomoea batatas (L.) Lam.) cells by particle bombardment and expressed in the regenerated plants. Microprojectiles coated with DNA of a binary vector pBI121 carrying CaMV35S promoter-GUS gene fusion and a neomycin phosphotransferase gene as selection marker were bombarded on embryogenic calli which originated from shoot apical meristem-derived callus and transferred to Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxyacetic acid and 100 mg/L kanamycin. Bombarded calli were subcultured at 4 week intervals for six months. Kanamycin-resistant calli transferred to MS medium supplemented with 0.03 mg/L 2iP, 0.03 mg/L ABA, and 50 mg/L kanamycin gave rise to somatic embryos. Upon transfer to MS basal medium without kanamycin, they developed into plantlets. PCR and northern analyses of six regenerants transplanted to potting soil confirmed that the GUS gene was inserted into the genome of the six regenerated plants. A histochemical assay revealed that the GUS gene was preferentially expressed in the vascular bundle and the epidermal layer of leaf, petiole, and tuberous root.

• Plant Biotechnology Reports
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• v.2 no.4
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• pp.245-252
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• 2008

The genetic status of somatic embryo-derived plantlets of Cymbopogon flexuosus was examined by randomly amplified polymorphic DNA (RAPD) analysis. Auxins such as 2, 4-dichlorophenoxyacetic acid (2, 4-D) (1-4 mg/l) were used in Murashige and Skoog (MS) medium for induction of calli from rhizomatous explants of Cymbopogon flexuosus. Optimum calli were induced on MS medium supplemented with 2, 4-dichlorophenoxyacetic acid (2, 4-D) (3.5 mg/l) alone or in combination with $N^6-benzyladenine$ (2 mg/l). Somatic embryogenesis was achieved from long term calli when cultured on MS medium containing 2, 4-dichlorophenoxyacetic acid (2, 4-D) (2 mg/l) along with $N^6-benzyladenine$ (BA) (1-2 mg/l). Regeneration was achieved when freshly induced embryogenic calli were sub-cultured on MS medium supplemented with $N^6-benzyladenine$ (3 mg/l) alone. Long-term cultured embryos showed profuse minute rooting on regeneration medium supplemented with N6 -benzyladenine (3 mg/l). Microshoots were rooted in the presence of indole-butyric acid (IBA) (2 mg/l). DNA samples from the mother plant and 18 randomly selected regenerated plants from a single callus were subjected to RAPD analysis with 6 arbitrary decamer primers for the selection of putative somaclones. A total of 64 band positions were scored, out of which 19 RAPD bands were polymorphic. From genetic similarity coefficient based on RAPD band data sharing, it was found that the majority of the clones were almost identical or more than 92% similar to the mother plant, except CL2 and CL9 (66%) which showed highest degree of genetic change with CL2 and CL9 showing presence of two non-parental bands each.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.3
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• pp.170-176
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• 1993

The yield, viability and continuous culture of isolated Italian ryegrass protoplasts were investigated. The effects of cold treatment (4^{\circ}C.$) for 7 days and basic LS medium supplemented with 5mg/l $AgNO_3$ showed effectively on embryogenic callus induction and regeneration responses of immature and mature embryos or young inflorescences subcultured every 4 weeks on basic medium. The optimum combinations of growth regulator on the regeneration responses was 0.2mg/l BAP and 2mg/l 2, 4-D. Calli induced inflorescences were suspended in its liquid medium for 5 days before enzyme treatment. Maximum protoplast yield and viability were obtained after digestion in enzyme solution contained 4% cellulase R10. 2% macerozyme and 2% pectinase in 0.6M mannitol. Cell division and microcalli development were observed in isolated protoplasts cultured in agarose culture of KM8P medium.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2000.10a
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• pp.114-115
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• 2000

Aralia elata is found in mountain areas all over Korean peninsula. Aralia elata is the scientific name for Japanese angelica tree. The tree belongs to the family Araliaceae, commonly known as ginseng family. Bud sprouts from apical shoot tip of the plants are rich in flavor and thus mainly used for both folk medicine and vegetable. The stalks with apical buds are gathered in the early spring and planted in sandy soil or water in the greenhouse. The sprouting buds are then collected and sold as fresh vegetable. Although the plants have been used for food, they have been cultivated in a very small scale. In spring, local farmers just go around mountain areas to search the trees and gather the stalks as much as they get and sell them to the market. No conservation efforts have been made to stop the exploitation or to save the dwindling population. We tried to provide local farmers with the plants that may be used as an alternative to stalks from wild populations. This will bel! p conserve the wild populations. However, it is hard to propagate them either by conventional cuttings or by seed germination in a short period of time. Mass propagation using tissue culture systems have shown a great promise with several woody plants. Recently we developed a mass propagation technique via somatic embryogenesis system using mature and/or juvenile explants for Aralia elata. Several factors affecting somatic embryogenesis system including SE(somatic embryo) induction, embryogenic callus proliferation, SE germination, plant regeneration and transplanting to field frill be presented. And some problems arising for the somatic embryogenesis system will be also discussed.

• Journal of Plant Biotechnology
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• v.32 no.2
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• pp.91-95
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• 2005

Agrobacterium tumefaciens-mediated immature embryo transformation was used to produce transgenic maize. Immature embryo of Hi II genotype were co-cultivated with strains Agrobacterium tumefaciens (C58C1) containing the binary vectors (pPTN290) carrying with Ubiquitin promoter-GUS gene as reporter gene and NOS promoter-nptll gene conferring resistance to paromomycin as selective agent. Seven embryogenic callus lines transformed showed the resistance in paromomycin antibiotics. Histochemical GUS assay showed that 7 individual lines transformed with the GUS gene were positive response among the transformants. Southern blot analysis revealed that the nptll gene segregated and expressed in their progeny.