• Korean Journal of Medicinal Crop Science
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• v.5 no.1
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• pp.21-27
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• 1997

This experiments were conducted to determine the effect of thidiazuron on forming tuberlets and plant regeneration of Pinellia ternata T. by tissue culture. The addition of $5\;{\mu}M$ TDZ to the medium had better regeneration than that of any other treatments of NAA and TDZ. At the combination treatments of NAA and TDZ, as the level of thidiazuron increased, the rate of shoot regeneration was incresed while the increment of NAA concentration inhibited the rate of shoot regeneration. The supplement of $5\;{\mu}M$ thidiazuron produced the best number of micro-tubers per explant and the number of micro-tuber formed was 25 in MS medium and 29 in MG medium on 30 day culture, respectively. Microtuber formation was the best on MG medium with 1.0 mg/l NAA and $5\;{\mu}M$ thidiazuron. MG medium was superior to MS and B5 medium for the growth of tuberlets. Half strength of MS medium with NAA 2 mg/l was the most effective for root formation. Rooting ability on nursery soil of plantlets produced in in vjtro was good as a 80% after 3 weeks.

• 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.

• Korean Journal of Plant Tissue Culture
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• v.22 no.1
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• pp.53-57
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• 1995

This study was carried out to investigate the effect of TDZ (thidiazuron) treatment on Propagation in vivo through scale cultures of Narcissus pseudonarcissus. Scales with disk (5 to 7 m in size) were cultured on MS medium containing NAA, BA and TDZ. Bulbs and shoots were directly formed when scales were cultured on medium containing 5 mg/L NAA and 1 mg/L BA. In addition, combination of 3 mg/L NAA and 0.02 mg/L TDZ promoted effectively the direct formation of bulbs and shoots. The shoots were rooted when cultured on medium containing 5 mg/L NAA and 0.02 mg/L TDZ. non scales obtained from regenerates were cultured on medium containing 1.0 mg/L NAA and 0.5 mg/L TDZ, they gave rise to numerous bulbs and shoots . The overall results suggest that TDZ is an effective plant growth regulator in vitro propagation of N. pseudonarcissus.

• Korean Journal of Agricultural Science
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• v.30 no.2
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• pp.115-122
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• 2003

This experiment was conducted to find the effect of a non-purine cytokinin, thidiazuron(TDZ), on the increase of berry size and fruit quality in 'Kyoho' grapes. For the comparison, the effect of forchlorfenuron(CPPU) was also examined The number of shot berries per cluster was significantly increased by the application of TDZ at 5 days after calyptra fall, resulting in the increase of cluster weight but no increase of each berry weight. The increase of berry weight was found when TDZ was applied at 10 to 15 days after calyptra fall. Gibberellin(GA $25mg{\cdot}L^{-1}$) was also effective on the increase of berry weight and the combined application of GA and TDZ further increased the berry weight. TDZ showed stronger effect on the increase of berry weight than CPPU at the same concentration. Berry ripening was more delayed at higher concentration of TDZ but no chemical injury was observed even at $20mg{\cdot}L^{-1}$. Results indicated that TDZ was effective on the quality improvement through berry weight increase and the recommended concentration TDZ for 'Kyoho' grapes was 5 to $10mg{\cdot}L^{-1}$.

• Horticultural Science & Technology
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• v.16 no.4
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• pp.520-524
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• 1998

This study was carried out to investigate the effect of thidiazuron(TDZ) on callus and shoot primordia formation, to determine the most optimum multiple shoot induction medium, and to obtain the plantlets on solid medium via shoot organogenesis. TDZ 0.01 mg/L in MS medium was most effective on callus formation, and BA 0.1 mg/L was most effective on shoot growth, while TDZ 0.01 mg/L was most effective on callus formation. TDZ 0.001 mg/L was most effective in shoot primordia formation. Shoot tips were cultured with TDZ 0.01 mg/L for 8 weeks and induced callus was transferred to regeneration medium containing TDZ 0.001 mg/L. After 4 weeks induced shoot primordia were resubcultured at growth regulator-free medium for 4 weeks. The induced multiple shoots rooted more efficiently at NAA 1.0, 5.0 mg/L, or IBA 5.0 mg/L.

• 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.8 no.1
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• pp.15-19
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• 2006

An efficient protocol for in vitro multiple shoot bud induction and plant regeneration from mature green cotyledon derived callus tissues of Acacia sinuata has been developed. Callus formation occurs at all the concentrations of thidiazuron (TDZ) in Murashige and Skoog's (MS) medium, but 0.6 ${\mu}M$ proved to be the best with maximum callus formation frequency. Supplementation of TDZ in combination with indole-acetic acid (IAA) in MS media accelerates shoot bud organogenesis in differentiating callus tissues with 60-70% conversion of shoot buds into shoot Most efficient shoot organogenesis was recorded when TDZ induced calli were subcultured at different concentrations of 6-benzyla-denine (BA). Optimum shoot bud induction and plant regeneration from callus was achieved when 0.6 ${\mu}M$ (TDZ) induced calli were subcultured at 3.0 ${\mu}M$ (BA) where $16.6{\pm}0.74$ shoots/unit callus on obtained. Rooting in in vitro differentiated shoots was achieved when transferred to medium containing different concentration of indole-3-butyric acid (IBA) in full & half strength MS medium. The well rooted plantlets were hardened and transferred to net house with 90% survival rate.

• Journal of Plant Biotechnology
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• v.31 no.1
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• pp.61-65
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• 2004

In order to micropropagate uniform plantlets of Alocasia cadieri Chantrier in vitro, the shoot tips were cultured on media containing various concentrations of BA and thidiazuron (TDZ). Multiple shoot formation from shoot tips was very effective on medium containing 0.1mg/L TDZ. The formed shoots from shoot tips were separated into a shoot, and cultured on media with BA, TDZ, and NM combination for proliferation. The shoots were multiplied very vigorously on medium with 0.5mg/L TDZ and 0.5mg/L NAA. The rooting and growth of multiplied shoots were more effective on medium with 2.0g/L activated charcoal, rather than those with IBA and NAA. Rooted plantlets show high survival in soil mixed with perlite 1: vermiculite 1 or vermiculite alone.

• Korean Journal of Medicinal Crop Science
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• v.13 no.5
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• pp.233-236
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• 2005

Centella asiatica accumulates large amounts of triterpene saponin, such as centellasaponin, asiaticoside, madecassoside. We examined the effect of two candidates, MJ (Methyl jasmonate) and TDZ (thidiazuron), on asiaticoside production and the accumulation of bAS mRNA associated with asiaticoside biosynthesis in leaves of cultured whole plants. The growth of whole plants treated with 0.1 mM MJ was found to decrease significantly, however, the growth of whole plants treated with 0.1 mM MJ plus 0.025 mg/l TDZ was better than that treated with MJ alone. When MJ alone was added to culture medium, asiaticoside contents in leaves were higher than that of control after 7 days of treatments. The maximum level of bAS $({\beta}-amyrin\;synthsae)$ mRNA in leaves of whole plant treated TDZ and MJ was transiently observed after exposure to 5 days. These results showed the up-regulation of bAS gene by adding TDZ and MJ at the molecular level, however, synergic effects of TDZ and MJ on asiaticoside biosynthesis were not testified.

• 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.