• Plant Biotechnology Reports
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• v.3 no.3
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• pp.175-182
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• 2009

Simple, reproducible, high frequency, improved plant regeneration protocol in Eastern Cottonwood (Populus deltoides) clones, WIMCO199 and L34, has been reported. Initially, aseptic cultures established from axillary buds of nodal segments from mature plus trees on MS liquid medium supplemented with $0.25mg\;1^{-1}$ KIN and $0.25mg\;1^{-1}$ IAA. Nodal and internodal segments were found to be extra-prolific over shoot apices during course of aseptic culture establishment, while $0.25mg\;1^{-1}$ KIN concentration played a stimulatory role in high frequency plant regeneration. Diverse explants, such as various leaf segments, internodes, and roots from in vitro raised cultures, were employed. Direct plant regeneration was at high frequency of 92% in internodes, 88% in leaf segments, and 43% in root segments. This led to the formation of multiple shoot clusters on established culture media with rapid proliferation rates. Many-fold enhanced shoot elongation and growth of the clusters could be achieved on liquid MS medium supplemented with borosilicate glass beads, which offer physical support for proliferating shoots leading to faster growth in comparison to semi-solid agar or direct liquid medium. SEM examination of initial cultures confirmed direct plant regeneration events without intervening calli. In vitro regenerated plants induced roots on half-strength MS medium with $0.15mg\;1^{-1}$ IAA. Rooted 5- to 6-week-old in vitro regenerated plants were transferred into a transgenic greenhouse in pots containing 1:1 mixture of vermicompost and soil at $27{\pm}2^{\circ}C$ for hardening and acclimatization. 14- to 15-week-old well-established hardened plants were transplanted to the field and grown to maturity. The mature in vitro raised poplar trees exhibited a high survival rate of 85%; 4-year-old healthy trees attained an average height of 8 m and an average trunk diameter of 25 cm and have performed well under field conditions. The regeneration protocol presented here will be very useful for undertaking genetic manipulation, providing a value addition to Eastern Cottonwood propagation in future.

• Journal of Plant Biotechnology
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• v.34 no.2
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• pp.153-159
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• 2007

Plant regeneration of Pulsatilla koreana was achieved via adventitious shoot formation indirectly from callus and directly from adventitious root segments. For the callus induction from leaf or petiole explants, combination of 2,4- dichlorophenoxyaceticacid (2,4-D) with $2.22\;{\mu}M$ 6-benzyladenine (BA) was effective. Adventitious shoot induction from callus was enhanced by the combined treatment with $0.1\;{\mu}M$ polyvinylpyrrolidone (PVP) compared to cytokinin treatment alone. Adventitious roots were induced from the petiole segments on 1/2 MS medium with $4.93\;{\mu}M$ IBA. High frequency direct adventitious shoot formation from the segments of adventitious roots was achieved on medium with $4.92\;{\mu}M$ 2-isopentenyladenine (2-ip). Elongated shoots were rooted on half-strength MS medium containing $5.71\;{\mu}M$ indole acetic acid (IAA). Regenerated plantlets with well-developed shoots and roots were successfully transferred to soil. This in vitro propagation protocol might be useful for mass propagation as well as conservation of this plant.

• Journal of agriculture & life science
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• v.43 no.6
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• pp.59-65
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• 2009

Combinations of plant growth regulators, darkness treatments, and the order of expanding leaves for explants were evaluated for optimizing in vitro shoot regeneration rate of 'Whangkeumbae' pear. In a MS medium, supplemented with $8.88{\mu}M$ 6-benzylaminopurine (BA) and $0.49{\mu}M$ indole-3-butyric acid (IBA), green foci were observed on the surface of the callus 8 days after culture initiation. Some adventitious buds were later induced from those green foci, resulting in the appearance of normal shoots. In a medium containing $22.20{\mu}M\;BA$, the surface of the callus became compact and greenish, and many adventitious buds were formed over the entire area of the callus surface. When comparing BA concentration via histological observation, the section which had been treated with $22.20{\mu}M\;BA$ exhibited closer cell aggregation than those with $8.88{\mu}M\;BA$. The darkness treatment enhanced the formation of adventitious shoots for up to 3 weeks. The youngest two expanding leaves, proximal to the shoot apex, were proved to be the most regenerative, and yielded the highest shoot number per regenerating leaf. A fourth strength MS medium, which was supplemented with $0.54{\mu}M\;NAA$, yielded good quality plantlets, with regard to root number and root length.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.34-41
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• 1991

To explore the possibility of introducing Zea mays transposable element Ac(activator) which can be used as a mutagen and gene tag in tobacco plants other than maitre, we tried to introduce a cloned Ac element into tobacco cells by an Agrobacterium tumefaciens binary vector system. Transformation of N. babacum cv. Burley 21 tissues and regeneration to whole plant were carried out. The frequency of the transformed callus induced in shoot induction media was higher than that of transformed callus induced in callus induction media. However, the calli were not grown in the second selection media, and became yellow senescent calli. Regenerated tobacco plantlets with foreign gene were also obtained in shoot induction media containing 100 $\mu\textrm{g}$/ml kanamycin and 100$\mu\textrm{g}$/ml carbenicillin. The leaf tissues of transformant was also resistant to 1000 $\mu\textrm{g}$/ml kanamycin. The chromosomal DNAs of transformant and normal plant of N. tabacum were digested by EcoR I and Hind III but not by Pst I.

• Journal of Plant Biology
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• v.37 no.3
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• pp.381-385
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• 1994

The highest degree of callus formation was obtained from the shoot tips of Dianthus superbus when cultured on the MS medium supplemented with 2.0 mg/L NAA and 0.5 mg/L BAP. Embryogenic calluses were obtained from the seperated friable calluses on MS medium containing 2.0 mg/L 2,4-D after 7-8 wk of culture. For plant regeneration, embryogenic calluses were selected and cultured on te proliferation medium. After 3 wk, somatic embryos appeared on MSK medium (0.5 mg/L NAA, 2.0 mg/L kinetin) and N6 medium (2.0 mg/L kinetin, 0.1 mg/LNAA, 0.1 mg/L 2,4-D and 2.0 g/L casein hydrolysate). When these somatic embryos were kept under continuous illumination, shoots were successfully regenerated on the both media. The shoots were rooted on MS medium supplemented with 2.0 mg/L NAA.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.67-72
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• 2004

An efficient protocol has been developed for rapid mass propagation of sweetpotato from shoot-tips derived embryogenic callus. Optimal embryogenic callus was induced from shoot apical meristem explants on Murashige and Skoog (MS) medium supplemented with 1mg/L 2,4-D. The addition of casein hydrolysate in the media increased the embryogenesis efficiency of sweetpotato. Somatic embryos were easily induced from the embryogenic callus on MS basal medium containing 300-500mg/L casein hydrolysate without phytohormon. Treatment of casein hydrolysate (100∼300mg/L) with 1mg/L 2,4-D also improved the secondary embryonic efficiency from somatic embryos below 2mm in length. Plant regeneration was achieved via somatic embryogenesis and direct organogenesis. Regenerated planlets with well developed shoots and roots on MS basal medium were successfully transferred to soil.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.412-418
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• 1989

The stem segments of Ailanthus altissima were cultured on the Murashige & Skoog's medium(1962) supplemented with 0.1 mg/l BAP and 1.0 mg/l 2, 4-D for callus induction and proliferation, Shoot primordia were observed as greenish regions on the surface of yellow-brown calli about 8 weeks after culture. Shoot primordia were selected and transferred to the MS media containing various combination of BAP and 2, 4-D. Among these combinations the shoot primordia cell clusters on the medium added to 0.5mg/l BAP and 0.01mg/l 2, 4-D exhibited the highest number of shoot formation. These shoots were successfully transferred on the solid MS medium with no growth regulators for the rootings.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.231-236
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• 2011

'Ggoma' is a new Hibiscus dwarf type variety developed by gamma irradiation at the Korea Atomic Energy Research Institute (KAERI). This study was conducted to determine the best optimum cultural callus formation and shoot regeneration condition. Sterilized leaf tissues were cultured on MS (Marashige and skoog's) medium containing 3% sucrose, 0.8% agar with different concentration and combination of TDZ, 2, 4-D, KT, BA, and 2iP for 4 weeks in vitro culture. MS medium containing 2,4-D $0.1mg\;l^{-1}$ and BA $0.5mg\;l^{-1}$ were most effective on callus formation and growth. After 4 weeks, callus was transferred on BA (0.5, 1, $1.5mg\;l^{-1}$) and TDZ (0.1, 0.2, $0.3mg\;l^{-1}$) for shoot formation. The best condition for inducing the shoot from callus was BA $1.5mg\;l^{-1}$ and TDZ $0.3mg\;l^{-1}$. This result will be useful for the rapid multiplication of Hibiscus syriacus L.var. Ggoma.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.04a
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• pp.80-80
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• 2019

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of (Fragaria x ananassa DUCH. cvs. 'Derunoka' and 'Jumbo pure berry'. The shoot tips of strawberry were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7M). Precultured explants were treated with loading solution (LS, C4) containing glycerol 17.5% and sucrose 17.5% for 40 min and exposed to dehydration solution (B1) containing 50% of glycerol and 50% of sucrose for 60 min at $25^{\circ}C$, and then transferred onto droplets containing $2.5{\mu}l$ PVS3 on sterilized aluminum foils ($4cm{\times}0.5cm$) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M Sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at $25^{\circ}C$ in both the cultivars. The viability of cooled samples, followed by culturing on MS medium for 4 weeks was 77.8% and 60.0% for 'Derunoka' and 'Jumbo pure berry', respectively. This result shows droplet-vitrification would be a promising method for cryobanking strawberry germplasm.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.675-683
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• 2018

This study describes an efficient and widely applicable droplet-vitrification following cryopreservation for shoot tips of Chrysanthemum morifolium (Ramat.) cvs. 'Borami' and 'Yes morning'. The shoot tips of Chrysanthemum were precultured in Murashige and Skoog (MS) liquid medium supplemented with sucrose (0.3-0.7 M). Precultured explants were treated with loading solution (LS, C6) containing glycerol 20% and sucrose 20% for 30 min and exposed to dehydration solution (B5) containing 40% of glycerol and 40% of sucrose for 60 min at $25^{\circ}C$, and then transferred onto droplets containing $2.5{\mu}l$ PVS3 on sterilized aluminum foils ($4cm{\times}0.5cm$) prior to direct immersion in liquid nitrogen (LN) for 1 h. The highest regeneration rate (%) was obtained when shoot tips were precultured with treatment-2 (exposing of shoot tips to MS + 0.3M sucrose for 30 h and then treated with MS+0.5 M sucrose for 16 h) at $25^{\circ}C$ in both the cultivars. The viability of cooled samples, followed by culturing on $NH_4NO_3$-free MS medium for first 5 days was increased to two-fold (80.7%) regrowth rate over those cultured on normal MS medium or MS medium containing plant growth regulators. This result shows droplet-vitrification would be a promising method for cryobanking chrysanthemum germplasm.