• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.269-273
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• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Journal of Plant Biotechnology
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• v.37 no.4
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• pp.465-471
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• 2010

We assessed whether the cow1 mutant defects are associated with growth of Tos17 and T-DNA insertional rice in blue light (BL). Growth of oscow1 mutants which encoded a member of the YUCCA protein family was retarded in BL. Root to shoot ratios of the mutants were reduced about 2 times lower in the absence of NAA and about 2.5 times lower in the presence of NAA; the shoot growth was not significantly changed by NAA addition. Photosynthetic activity of the mutants was however inhibited in high light. Pigment analysis showed significant difference between wild-type (Chl a:b = 3.02) and mutants (3.84). Carotenoid contents of the mutants were also decreased considerably, implying the involvement of cow1 in pigment formation. These findings lead us to suggest that the growth retardation of oscow1 mutant plants by BL results from the difference of photosynthetic activity in part.

• Journal of Plant Biotechnology
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• v.36 no.4
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• pp.403-406
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• 2009

This study was conducted to develop an effective production of callus induction and plant regeneration system for garlic transformation. The best callus production occurred on in vitro root segment initially cultured on MS medium with 1.0 mg/L 2,4-D and 0.2 mg/L IAA in both ‘Danyang' and ‘Euseong'. The frequency of callus formation were 81.2% ‘Danyang' and 76.1% ‘Euseong'. Eight weeks after callus induction, callus lines were transferred to regeneration medium during 7 weeks. The best shoot regeneration medium was MS supplemented with 5 mg/L Kinetin and 1 mg/L NAA for ‘Danyang' and MS supplemented with 10 mg/L BAP for ‘Euseong'. The frequency of shoot regeneration were 51.5% ‘Danyang' and 56.6% ‘Euseong' The plantlets were acclimatized and transferred to the greenhouse with almost survival. This in vitro regeneration system should be useful for garlic transformation.

• Journal of Life Science
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• v.16 no.5
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• pp.856-858
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• 2006

The study was carried out to develop efficiency of transformantion in pepper plants. We used cotyledons of two native varieties, 'Subicho' and 'Kumtap' to establish some conditions of plant regeneration. Differentiation rate of shoot was higher in 2 to 4 mg/l zeatin and 0.05 mg/l NAA than in other treatments. Meanwhile, differential rate of roots was the highest in 0.5 mg/l NAA.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.535-539
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• 2001

To establish the cultural practices of persimmon in heated plastic house, the growth and flower bud differentiation of 4-year old 'Nishimurawase' persimmon tree planted in 80 L pots were investigated. Temperature was kept at above $18^{\circ}C$. The earlier heating induced the earlier flower bud differentiation, while the number of days from bud burst to flower bud differentiation was 70-75 days, which was not affected by the date of heating. The date of flower bud differentiation in 'Nishimurawase' persimmon was May 1, May 21, and June 1 in the plastic house heated from Jan. 15, Feb. 15, and Mar. 15, respectively. The number of flower primordia per bud in the plastic house was 6.2-7.1, slightly fewer than that of 7.8 in the open-field, with the tendency of increasing the number by earlier heating. The days required for the differentiation of the last flower bud primordia from the beginning of differentiation of the first bud were 40-60, and that required for the flower bud differentiation of all buds on the same shoot was 30. The total carbohydrates in shoot increased and the contents of nitrogen decreased, resulting in increased C/N ratio just before flower bud differentiation, and it coincided with the time when the total carbohydates increased above 15%. During two weeks before flower bud differentiaton, The contents of zeatin per 1 g dry matter of shoot drastically increased from $27.2{\mu}g$ to $47.3{\mu}g$, while that of IAA slightly decreased from $188.6{\mu}g$ to $172.4{\mu}g$, and that of GA decreased from $2,225{\mu}g$ to $1,555{\mu}g$.

• Korean Journal of Agricultural Science
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• v.14 no.2
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• pp.205-212
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• 1987

To examine the morphogenetic response, stem segments of 8 Populus spp. and 3 different explants of P. nigra var. italica were cultured on MS (Murashige and Skoog 1962) and WPM (Woody Plant Medium) medium containing various phytohormones. The results obtained were as follows: 1. Shoot regeneration and development from stem segment of 8 Populus spp. showed a quite difference according to the section and the species. All of the species of Leuce and Tacamahaca section did not form adventitious buds, while most of explants showed axillary or dormant bud elongation after 4 weeks. But P. nigra var. italica of Aigeiros section showed a successful adventitious bud formation (mean 5.4 buds per explant). 2. Leaf, petiole, and internode segment of P. nigra var. italica showed a quite differences according to media and ex plants upon the morphogenetic response. Adventitious bud formation from leaf was more abundant and readily initiated on the abaxial side than on the adaxial side. Mean number of 103 adventitious buds per explant was obtained from abaxial side of leaf segment cultured on WPM medium containing $0.2mg/{\ell}$ BAP for 5 weeks. 3. 2,4-D (2,4-dichlorophenoxy acetic acid) supplemented to media appeared to be negative upon the adventitious bud formation of P. nigra var. italica, while it promoted callus formation from all explants. Especially, NAA (${\alpha}$-naphtalene acetic acid) or NAA combination with BAP (6-benzylaminopurine) promoted root regeneration from the all explant of P. nigra var. italica in this study.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.287-292
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• 2005

Calli were induced by culturing the leaf segment of Actinidia deliciosa ${\times}$ A. arguta clone 118 on MS medium supplemented with 0.5 mg/L 2,4-D, 0.1 mg/L NAA and 0.05 mg/L BA for 8 weeks in light condition. The induced calli were inoculated in liquid MS medium containing 0.5 mg/L 2,4-D, 0.1 mg/L NAA, 0.05 mg/L BA and 3% sucrose to establish cell suspension culture. The cells at the exponential stage and the stationary stage could be observed between 5-11 days and after that 12 days in culture, respectively. The fresh weight of callus induced from the suspended cells did not vary much among the media containing eight different combinations of plant growth regulators tested. The highest frequency of shoot induction (88.3%) was observed in MS medium containing 2.0 mg/L zeatin. Either BA or zeatin mixed with thidiazuron (TDZ) seemed to be effective in shoot induction. The induced shoots were transferred to MS medium containing 0.2 mg/L zeatin for further shoot growth. And then the shoots were transferred to Standardi (ST) medium containing 1.0 mg/L indolebutyric acid (IBA) for rooting. Plantlets could be obtained through cell suspension culture of Actinidia deliciosa ${\times}$ A. arguta clone 118.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.31-35
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• 2004

In order to develop an efficient micropropagation technique for an endangered species, Stellera rosea N., stem node cultures were conducted on MS medium supplemented with cytokinins. Generally, BA was better than zeatin on shoot proliferation from stem nodes, whereas zeatin showed more effective on shoot elongation. In vitro rooting of shoots was achieved by application of an auxin pre-culturing method. Overall rooting rate was relatively low and differed depending on the culture period. Pre-culturing of shoots for 15 days at 1.0mg/L IBA revealed a slightly better rooting efficiency reaching 30％ rooting rate than NAA. Root induction rate by NAA also varied with concentration of NAA and culture periods. Total 51％ of the rooted plantlets survived on artificial soil mixture and grew normally without any distinct morphological variation. The results suggest that the endangered Stetllera plants are propagated via in vitro culture system, but still need to more study for the improvement of rooting and acclimatization of the plantlets in soil.

• Journal of Korean Society of Forest Science
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• v.82 no.1
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• pp.26-33
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• 1993

In vitro shoot proliferation and rooting were tested for 2-0 seedlings of half-sib families of 4 plus oaks trees. Nodal segments having axillary buds from 37 families(16 of Quercus acutissima, 10 of Q. variabilis, 7 of Q. serrata, and 4 of Q. mongolica) were cultured on WPM(Woody Plant Medium) supplemented with 0.5 mg/l BA (6-benzyladenine) and 0.01 mg/l NAA(${\alpha}$-naphthalene acetic acid) and subcultured at 2-3 weeks of intervals fur 6 months. In vitro rooting was carried out on GD(Gresshoff and Doy) medium supplemented with 0.5mg/l IBA(indole butyric acid). The capacity for shoot proliferation and rooting was highly varied with families. Generally, white oaks(Q. serrata and Q. mongolica) showed poor response than black oaks(Q. acutissima and Q, variabilis) in shoot proliferation and rooting. Among the total of 37 families, 7 of Q. acutissima, each 2 of Q. variabilis, Q. serrata, and Q. mongolica revealed abilities for continuous shoot proliferation, and the others failed to proliferate. Rooting of the selected oak trees also greatly varied among the families. In Q. acutissima, rooting ratio ranged from 10.0%(CB 25. KG 4) to 89.8%(CB 18). Although 26.7% of KG 16 in Q. variabilis, 3.3% of JN 15 in Q. serrata were rooted, Q. mongolica was not rooted at all in this experimental conditions. No relationship between shoot growth and the rooting ability was observed. Present results suggest the possibility of large-scale micropropagation, but further studies on family differences, shoot-tip necrosis, and callusing of rooting junction are still required to develop reliable micropropagation systems.

• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.263-267
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• 2003

This study was conducted to evaluate the effect of thidazuron(TDZ) on shoot proliferation and growth from axillary buds of 20-years-old Corylopsis coreana. Shoots proliferation was effectively achieved on WPM(Woody Plant Medium) supplemented with 0.03∼0.1mg/L TDZ. The highest shoot number(6.5$\pm$0.7) was obtained on 0.1mg/L TDZ treatment. On the TDZ medium shoots formed as clusters less than 1cm in height and therefore needed to subculture on GA$_{3}$ containing medium to induce elongation. In consecutive cultures, phenolic compounds were excreted at the proximal part of the explants and inhibited growth of the explants. Growth inhibition by the compounds was overcome using liquid and paper bridge culture system. About 60％ of the elongated shoots rooted on half- strength MS medium containing IBA. Generally, IBA was mire effective on in vitro rooting than NAA with optimal range of 0.5mg/L to 1.0mg/L. Rooted plantlets were transferred in an artificial soil(vermculite) and acclimatized in high humidity greenhouse condition. Survival rate differed greatly depending on rooting types of the explants. Two types of rooting were observed. The first type was direct rooting from the explants. The second type was callus formation followed by rooting from the callus. The explants showing the 1st type rooting survived can be multiplicated in vitro by TDZ treatment followed by elongation with GA$_{3}$ and rooting with IBA.