• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.228-234
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• 2015

Using either the apical or axillary bud of the endangered species Abeliophyllum distichum Nakai, we tested the effect of bud position and culture method on shoot proliferation and rooting. In shoot proliferation, the axillary bud explant was more effective than the apical bud and the effect was fostered by BA treatment, whereas no differences were observed in shoot elongation by the explant position. Spontaneous rooting was observed in the MS basal medium and resulted in conspicuous differences in the explant position : more than 80% in apical bud explant and 28% in axillary bud explant was achieved, respectively. The positional effects were also observed in BA pre-treatments: generally vertical culture method appeared to be better in shoot proliferation, growth, and rooting than that of the horizontal culture method regardless of the BA pre-treatment duration. The highest shoot multiplication was achieved through the vertical culture method with axillary bud explant, whereas the best shoot elongation and rooting was obtained using the vertical culture method with the apical bud explant. Apical bud explant was superior to axillary bud explant in ex vitro micro-cuttings and revealed a significant difference in shoot growth and root development. The above results suggest that explant position and culture method influence the efficiency of micropropagation for a rare and endangered plant Abeliophyllum distichum.

• Plant Biotechnology Reports
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• v.5 no.1
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• pp.35-43
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• 2011

This communication describes for the first time an efficient and reproducible protocol for large-scale multiplication of Bambusa nutans. Nodal segments collected from field-grown clumps and cultured on Murashige and Skoog (MS) medium supplemented with $4.4{\mu}M$ benzylaminopurine (BA) and $2.32{\mu}M$ kinetin (Kin) gelled with 0.2% gelrite yielded 80% aseptic cultures with 100% bud-break. The in vitro-formed shoots obtained after bud-break were successfully multiplied in MS liquid medium supplemented with $13.2{\mu}M$ BA, $2.32{\mu}M$ Kin, and $0.98{\mu}M$ indole-3-butyric acid (IBA). Sub-culturing of shoots every 3 weeks on fresh multiplication medium yielded a consistent proliferation rate of 3.5-fold. Shoot clusters containing three to five shoots were successfully rooted with 100% success on half-strength MS liquid medium supplemented with $9.8{\mu}M$ IBA, $2.85{\mu}M$ indole-3-acetic acid (IAA), $2.68{\mu}M$ naphthaleneacetic acid (NAA), and 3% sucrose. Plantlets grown in vitro were acclimatized and subsequently transferred to the field. Inter-simple sequence repeat analysis has confirmed the genetic uniformity of the tissue-cultured plants up to 27 passages.

• Journal of Korean Society of Forest Science
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• v.99 no.4
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• pp.568-572
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• 2010

In order to develop an efficient micropropagation system for a rare tree species, Empetrum nigrum var. japonicum K. Koch, the effect of medium salt, cytokinins and auxin at different concentration were evaluated. Shoot induction from axillary bud was better on WPM medium than on MS medium. Although there was no significant differences observed in shoot induction among the salt strengths of WPM medium, whereas healthy shoots were developed on basal WPM medium. In comparison of the cytokinins affecting shoot proliferation, zeatin was better than BA, whereas BA exhibited more effectiveness on shoot elongation. In vitro root formation was better on WPM medium than on 1/2MS medium and achieved the highest rooting rate when 5.0 mg/L IBA treatment. 93% of rooted plantlets were survived on artificial soil mixture after 4 weeks of acclimatization. Above results suggest that a rare tree species, E. nigrum var. japonicum can be micropropagated via axillary bud cultures.

• Korean Journal of Plant Tissue Culture
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• v.26 no.4
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• pp.271-274
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• 1999

This study was undertaken to develop an efficient propagation technique for mature Betula davurica. Using aseptic materials taken from in vitro culture, the effects of media and plant growth regulators on shoot proliferation and rooting were investigated. DKW medium turned out to be the best in shoot proliferation among the media tested. Whereas axillary buds were better culture material than apical buds in proliferation of shoots, apical buds were slightly better than axillary buds on shoot elongation. Neither 1 /2 MS nor WPM medium seemed to be suitable for shoot multiplication or elongation. When the explants were cultured on 1/2 MS medium, shoot elongation was retarded by forming big callus at the base. In the case of WPM, shoots could be formed normally, but they exhibited slow growing. NAA was so effective on in vitro rooting that more than 80% rooting could be achieved on half-strength DKW medium supplemented with 1.0 mg/L NAA after 4 weeks in cultures. Ex vitro rooting using elongated shoot was also applicable to rooting and acclimatization. Rooted plantlets were successfully acclimatized in an artificial soil mixture and grew normally. The results demonstrate that efficient mass propagation of mature B. davurica can be done through tissue culture.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.401-408
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• 1984

This study was conducted to determine the optimum concentrations of growth regulators and their responses on the clonal propagation in axillary bud culture. Cultivars, Hongmi and Shinmi, responded differently to the levels of growth regulators, proliferation rate and shoot growth. The shoot and root of Hongmi cultivar in axillary bud culture were conspicuously induced by combination of NAA(0.1mg/l) and Kinetin(1mg/l) while Shinmi cultivar were affected by the single concentration of Kinetin(1mg/l) and BA(0.1mg/l), and also by the combination of NAA(0.1mg/l) and Kinetin(1mg/l). Better shoot growth and root initiation were obtained in the combination of NAA(0.1mg/l) and Kinetin(1mg/l) regardless of cultivars used when 5mm axillary buds were cultured. The shoots regenerated at the high levels of BA(1-5mg/l) were abnormally thicker and narrower leaves than normal plants and short in shoot height. Frequencies of abnormal plants were higher than that of the low level (0.1mg/l) of BA.

• Korean Journal of Medicinal Crop Science
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• v.14 no.5
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• pp.278-281
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• 2006

The effect of plant growth regulators was investigated on in vitro shoot proliferation from axillary bud explants of Hypericum erectum. To determine the optimal cytokinin for proliferation of axillay buds, we carried out screening four cytokinins (BA, kinetin, 2iP, TDZ). When nodal segments were cultured on MS medium supplemented with $4.5\;{\mu}M$ TDZ (thidiazuron), a number of shoots were induced. Our results indicated that the addition of TDZ to culture medium resulted in the induction of significantly more axillary buds than in the addition of other cytokinins. The optimal concentration of TDZ for proliferation of axillary buds was $10\;{\mu}M$. 92% of shoots spontaneously rooted without any plant growth regulator (PGR) and formed whole plantlets within one month. More than 95% of these regenerants survived and they did not show any detectable variation in morphology or growth characteristics compared to their donor plants.

• Journal of Plant Biotechnology
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• v.29 no.2
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• pp.117-121
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• 2002

We have developed an in vitro micropropagation system via shoot formation from axillary buds using nodal segments of Corylopsis coreana. Explants from both juvenile tree (one-year-old greenhouse stock seedlings) and mature tree (ten-years-old tree in nursery) were compared with regard to propagation efficiency. Combined treatment of both BA and zeatin were effective on shoot proliferation since the best result was obtained on MS medium supplemented with 0.5∼3.0 mg/L zeatin and 0.2 mg/L BA. Generally, juvenile explants were better in both shoot proliferation and growth than mature explants. However, as the duration of in vitro culture was proceed to 6 months, explants from mature tree also produced three shoots per explant. Distinctive differences in rooting and adaptability to soil of shoots obtained from mother trees. Whereas shoots originated from juvenile explants rooted as high as 97%, those from adult explants showed 62% rooting. Similar result was also observed in soil acclimatization. The plantlets derived from juvenile plants survived 67%, while only 48% of those from adult trees survived. The results showed a possibility of the micropropagation of Corylopsis coreana through shoot formation from axillary buds. In addition, the advance of the research still remain to enhance the frequency of acclimatization of plantlets from mature trees for practical application.

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.51-55
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• 2000

To investigate the effect of media and growth regulators in micropropagation of persimmon (Diospyros kaki Thunb.), dormant axillary buds taken from trees of persimmon cultivars such as Ichikikeijiro, Tonawase and Hiratenenashi were used. Shoot tips were successfully cultured in full or half of nitrogen strength of MS medium. The most effective cytokinins for shoot proliferation and elongation of persimmon cv. Ichikikeijiro were 5 mg/L and 2 mg/L zeatin, respectively. Shoots were successfully rooted in 1/2N-MS medium with 1 mg/L IBA.

• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.430-434
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• 1997

Axillary bud explants from 3-year-old seedlings of Forsythia saxatilis N., rare and endangered species in Korea, were cultured on Murashige and Skoog's medium. The effect of various cytokinins(BAP, kinetin, and zeatin) at the different concentration(0.2, 0.5 and 1.0mg/L) was tested. Although an apparent shoot proliferation was not observed, zeatin showed slight promotional effect on normal shoot and leaf development. Both shoots and adventive roots could be induced simultaneously when the explants were cultured on the medium with kinetin, but adventive rooting was gradually reduced according as BAP and zeatin concentrations increased. Axillary shoot growth was promoted by the etiolation treatment. Shoot proliferation has been maintained more than three years with consecutive subculture. Rooted plantlets were successfully acclimatized in the artificial soil mixture and showed normal growth after transplantation into field.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.49-53
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• 2004

Shoot formation was investigated from in vitro cultivation of exotic hybrid poplar (Populus koreana ${\times}$ P. trichocarpa) with a specific stomatal character occurring both upper and lower surface of leaves. Two different explants (stem and leaf segment) of Peace poplar were cultured on half strength Murashige and Skoog (MS) basal medium supplemented with the various concentrations of thidiazuron as a plant growth regulator. Most adventitious shoots were produced from excised ends of stem or mid-veins of leaf segments. The highest average numbers of shoots were 7.1 and 5.3 with the treatments of 0.02mg/L TDZ in both explants of stem and leaf segment. The highest shooting rates were achieved to 83.3％ and 47.6％ with the concentrations of 0.01mg/L and 0.02mg/L TDZ by axillary bud and leaf cultures, respectively.