• Korean Journal of Plant Tissue Culture
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• v.24 no.5
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• pp.285-289
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• 1997

Leaf and stem explants of Sedum erythrostichum Miq. were cultured on MS medium supplemented with various combinations of growth regulators. After two weeks of culture, 100% of the leaf explants formed calli on medium containing 2.0 mg/L 2, 4-D and 1.0 mg/L BA. Callus proliferated when subcultured on medium containing 2.0 mg/L 2, 4-D and 1.0 mg/L BA. Numerous adventitious buds were regenerated from callus cultured on the medium containing 2.0 mg/L NAA and 1.0 mg/L BA. Root formation from shoot was occurred on the MS basal medium containing 1.0 mg/L IAA.

• Korean Journal of Medicinal Crop Science
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• v.13 no.6
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• pp.273-277
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• 2005

Adventitious shoots were directly induced from leaf explants of R. glutinosa, an important medicinal plant. Proliferating shoot cultures were obtained by culturing leaf discs on Murashige and Skoog(MS) medium alone or combination with auxins and cytokinins. MS medium supplemented with 1 $mg/{\ell}\;BA\;and\;2\;mg/{\ell}$ IAA was the most effective, providing high shoot bud formation frequency without formation of intervening callus. The effect of leaf age on adventitious shoot formation was also investigated. The maximum shoot bud production (93.4%) was achived using 3rd leaf from apex of 6 weeks old plantlets after seed germination. Plantlet were rooted on an half-strength MS (1/2MS) medium containing 0.1 $mg/{\ell}\;IBA$. This prtocol is useful for clonal propagation and Agrobacterium-mediated transforamtion in R. glutinosa.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.299-302
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• 1994

Immature zygotic embryos (up to 4mm in length) were cultured on MS medium supplemented with 0.5 to 8mg/L 2,4-D. Up to 87% of them formed somatic embryos on the plumule without producing an intervening callus. The site of somatic embryo formation was confirmed by culturing plumule explants, which consisted of shoot apical meristem domes with 1 or 2 leaf primordia excised from 2-week-old seedlings. When the concentration of 2,4-D was increased over 4 mg/L, the plumule explants produced nonembryogenic calli only, whereas the distal end of the cotyledons directly formed numerous somatic embryos at frequencies of up to 60%. Upon transfer onto MS basal medium,2 out of 15 somatic embryos converted into plantlets. The plantlets were potted to a soil mixture and grown to maturity in a phytotron.

• Plant Biotechnology Reports
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• v.2 no.1
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• pp.33-39
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• 2008

In this paper, we would like to show unexpected morphogenic potential of cell suspensions derived from seedling explants of Gentiana kurroo (Royle). Suspension cultures were established with the use of embryogenic callus derived from seedling explants (root, hypocotyl and cotyledons). Proembryogenic mass proliferated in liquid MS medium supplemented with $0.5mg\;l^{-1}$ 2,4-D and $1.0mg\;l^{-1}$ Kin. The highest growth coefficient was achieved for root derived cell suspensions. The microscopic analysis showed differences in aggregate structure depending on their size. To assess the embryogenic capability of the particular culture, 100 mg of cell aggregates was implanted on MS agar medium supplemented with Kin ($0.0-2.0mg\;l^{-1}$), $GA_3$ ($0.0-2.0mg\;l^{-1}$) and AS ($80.0mg\;l^{-1}$). The highest number of somatic embryos was obtained for cotyledon-derived cell suspension on $GA_3$-free medium, but the best morphological quality of embryos was observed in the presence of $0.5-1.0mg\;l^{-1}$ Kin, $0.5mg\;l^{-1}$ $GA_3$ and $80.0mg\;l^{-1}$ AS. The morphogenic competence of cultures also depended on the size of the aggregate fraction and was lower when size of aggregates decreased. Flow cytometry analysis reveled luck of uniformity of regenerants derived from hypocotyl suspension and 100% of uniformity for cotyledon suspension.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.192-197
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• 2009

Camptotheca acuminata, a native of South China is a well known natural source of monoterpene-indole alkaloid camptothecin(CPT), one of the most promising anti-tumoural compounds. This study was conducted to optimize plant growth regulators and culture conditions on plantlets regeneration through organogenesis from callus of Camptotheca acuminta. Callus were induced from various explants of in vitro germinated plantlets of C. acuminta using WPM medium containing 0.2 ㎎/L 2,4-D. Hypocotyl segments were exhibited higher embryogenic callus than the other explants. Shoot buds formation from embryogenic callus was affected by plant growth regulators, pre-treated dark condition and liquid culture. Organogenesis was optimal in WPM liquid medium containing 0.5 ㎎/L BA. The dark pre-treatment for 2 weeks before the solid culture was effective for organogenesis. The regenerated shoots were rooted in WPM medium with 0.2 ㎎/L NAA and successfully acclimated in green-house conditions.

• Journal of Plant Biotechnology
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• v.46 no.1
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• pp.17-21
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• 2019

Ginger is an important monocotyledonous plant belonging to the family Zingiberaceae. The objective of this study was to investigate the regeneration potential of ginger using leaf base explants. Auxins such as 2, 4-D and NAA in combination with BA were used for initiation of callus. Different combinations of both ammonium ($NH^{4+}$) and nitrate ($NO^{3-}$) were also studied for efficient callus production. High frequency of white friable calli was observed on modified Murashige and Skoog (MS) medium supplemented with 2.0 mg/L 2, 4-D, 0.5 mg/L NAA and 0.5 mg/L BA. The highest shoot induction (92.33%), shootlets number ($7.33{\pm}0.33$) and length ($88.33{\pm}4.40$) mm were achieved on MS media containing 0.5 mg/L BA. Regenerated shoots were transferred to in vitro rooting media containing 1.0 mg/L IBA. Afterwards, plantlets with well-developed root and shoot system were subjected to a twostep hardening process. 71% of plantlets survived after secondary hardening without any abnormal morphology.

• Journal of Plant Biotechnology
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• v.48 no.2
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• pp.93-99
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• 2021

This study was conducted to develop an Agrobacterium-mediated genetic transformation protocol for the carnation cv. "Jinju" to counteract its ethylene sensitivity. The new protocol involves the use of an improved shoot regeneration medium, optimized minimal concentrations of the selective agent, a pre-culture period, and co-cultivation periods. Silver nanoparticles (NAg) added at a concentration of 2.0 μM to the Murashige and Skoog (MS) basal shoot regeneration medium supplemented with 0.1 mg/L indole-3-butyric-acid (IBA) and 0.2 mg/L thidiazuron (TDZ) improved the shoot regeneration efficiency, number of shoots per explant, and plant growth compared to the control without the addition of NAg. The phosphinothricin (PPT) concentration of 1.0 mg/L was determined to be the minimal and optimal concentration for the selection of putative transgenic plants. When the explants were infected with Agrobacterium cells harboring the acdS gene, the explants that were pre-cultured for three days induced more putative transgenic plants than those that were co-cultivated for four days. Therefore, we expect that the results of this study will benefit researchers who are developing genetic transformations of carnations.

• The Plant Pathology Journal
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• v.39 no.2
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• pp.220-227
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• 2023

Rose crown gall caused by Agrobacterium tumefaciens is a major disease that damages the production of cutroses in Korea. The effective prevention methods for this disease include the use of resistant varieties. This study was conducted to evaluate the resistance of 58 Korean cultivars and six foreign cultivars to crown gall disease with nodal explants in vitro. Among 180 A. tumefaciens strains, pathogenic strain RC12 was selected as an inoculant strain. The strain RC12 was identified based on characteristics of some selective media, pathogenicity test, and polymerase chain reaction analysis. Forty rose cultivars formed tumors on explants inoculated with A. tumefaciens RC12. However, 24 cultivars, including 22 Korean cultivars and 2 foreign cultivars, showed resistance to A. tumefaciens RC12 without forming any tumors. Six cultivars with tumor formation rates of over 30% formed initial tumors within 23 days after inoculation. Six cultivars with low tumor formation rates of around 5% formed initial tumors after 28 days of inoculation. It was found that gall formation rate was highly correlated with the initial gall formation period. Thus, the relationship between the period of gall formation and the rate of gall formation could be useful for assessing resistance to crown gall disease. In vitro inoculation methods could be used to evaluate resistance of cut-rose cultivars to crown gall diseases.

• Journal of Plant Biology
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• v.37 no.3
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• pp.257-262
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• 1994

The tomato (Lycopersicon esculentum Mill.) mutant diageotropica (dgt) lacking normal gravitropic response is known to be less sensitive to auxin compared with its isogenic parent VFN8. Straight growth as well as ethylene production in response to added auxin in hypocotyl segments of dgt was negligible. However, there was no significant difference between the two genotypes in auxin transport in petiole segments and its inhibition by the phytotropin N-1-naphthylphthalamic acid(NPA). Kinetic parameters of NPA binding to microsomal membranes were also non-distinguishable between the two. Its petiolar explants treated with ethylene developed epinastic curvature with the magnitude of response increased about 3 folds over non-mutant wild type. Ethylene-induced epinasty in both dgt and VFN8 was nullified by treatment of explants with the ethylene autagonist 2,5-norbonadiene. Lateral transport of 3H-IAA toward the upper side of ethylene-treated petioles in dgt, however, was not significantly more pronounced than in VFN8, the implications being that auxin sensitivity in the mutant was restored, or even rised above the wild type, by ethylene.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.110-116
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• 2018

This study was conducted to develop a simple, rapid, and reliable method for in vitro propagation of disease-free and true-to-type clones from sucker explants of thornless blackberry (Rubus fruticosus L. ${\times}$ R. parvifolius L.). To induce multiple shoots, the sucker explants were sterilized in 1% NaOCl solution, and then were aseptically cultured on the full and 1/2 MS solid medium supplemented with BAP (0.1, 0.5, 1.0, 2.0 mg/L). After six weeks of culture, the highest frequency (85.4%) of shoot formation from sucker explants was obtained on the full-strength MS medium with 1.0 mg/L BAP. Node explants obtained from multiple shoots were cultured on the various media of full- or half-strength of AD, B5, MS, SH, QL, WPM media, respectively. After 30 days of culture, plant growth was good on the half-AD, half-QL medium. After 90 days of culture, plant growth was good on the full MS and full SH medium. The survival rate of the plantlets after transfer to plastic pots containing soil mixture (sand: soil: vermiculite was 1:1:1, vol.) in the greenhouse was 98%. The results indicate that a multiple-shoot procedure can be applied for an efficient mass propagation of Rubus fruticosus L. ${\times}$ R. parvifolius L.