• Korean Journal of Plant Tissue Culture
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• v.24 no.1
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• pp.53-55
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• 1997

The shoot tips of Delphinium cv. Princess Caroline were cultured on the MS medium supplemented with cytokinin and auxin alone or in combination. Among cytokinins, BA was most effective in shoot multiplication, adequqte concentrations being 1.0-5.0 mg/L. Shoot multiplication was very favorable on the media with 1.0-3.0 mg/L BA and 0.1-0.5 mg/L IAA. Additions of BA and IAA did not stimulate shoot multiplication, but increased a little fresh weight. Shoots were scarcely rooted on the media with IBA or NAA, and were not done utterly on the media containing activated charcoal. Therefore, shoots were treated by Rootone and planted in the cultural media for in vivo rooting. The highest rate of rooting was 68% in the mixed cultural medium composed of Perlite 1 and Vermiculite 1.

• Korean Journal of Plant Tissue Culture
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• v.28 no.1
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• pp.25-32
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• 2001

Shoot tips of grape were cultured in uitro and tried to identify optimal culture conditions for regeneration, multiple shoot formation from meristemoid tissue and those subsequent elongation of multi-shoots. Healthy growing shoots were taken in early May, rinsed with running tap water, soaked in a neutral detergent and washed with soft brushing, and washed out with tap water, then sterilized with 10g Ca(ClO)$_2$/140 mL distilled water (Wilson's solution) for 5 min. Survival percentage of the cultures which were sterilized as above procedures was highly increased, compared with the other sterilized method. Propagation of multi-shoots from meristemoid showed a good response in 3/4 strength MS medium enriched with 0.1 mg/L NAA and 3.0 mg/L BA. Shoot elongation from multi-shooting clump well occurred in 3/4 strength MS medium supplemented with 80 mg/L adenine sulfate, 0.1 mg/L NAA and 1.0~2.0 mg/L BA.

• Korean Journal of Plant Tissue Culture
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• v.22 no.2
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• pp.83-87
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• 1995

Regulation of organ differentiation by growth regulators was investigated through the shoot-tip and bulb-scale cultures of Lilium longiflorum (cv Georgia). When shoot tips were placed on MS medium supplemented with 0.1 mg/L NAA alone or 0.1 mg/L NAA and 0.1 mg/L BA, axillary shoots were proliferated. Root diffentiation and growth were stimulated on the basal medium. Although growth regulation did not seem to be necessary when bulb scales were used as explants for shoot differentiation, its differentiation was promoted vigorously by 0.2 mg/L NAA, but suppressed by BA. Bulblets were formed from bulb-scale-derived plantlets cultured on MS medium supplemented with 0.1 mg/L IBA. And more bulblets were formed from the plantlet in MS medium supplying 0.2 mg/L NAA with 6% than3% sucrose

• Plant Biotechnology Reports
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• v.3 no.4
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• pp.333-340
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• 2009

Developmental anomalies in the plumule meristem of peanut (Arachis hypogaea L.) somatic embryos resulted in poor shoot differentiation and reduced plant recovery. Existing meristems with caulogenic potential have never been tested for embryogenesis in peanut. The present experiment was designed to test the mature zygotic embryo axis derived plumule with three meristems for somatic embryogenesis. Embryogenic masses and embryos developed from the caulogenic meristems in the axils. Exposure of 2 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation temporarily which then regained the ability to form the shoot on withdrawal of 2,4-D. Exposure of 4 weeks in primary medium with $90.5{\mu}M$ 2,4-D suppressed the shoot tip differentiation irreversibly. No shoot formation was noted from the tips in any of the cultures which were in secondary medium with $13.6{\mu}M$ 2,4-D. Development of somatic embryos directly from axillary meristems was confirmed histologically. Conversion frequency of these embryos was 11%. Thus, in this report, we describe a method to obtain somatic embryos from the determined organogenic buds of the axillary meristem, by culturing the nodal explant vertically on embryo induction medium. It also displays the possibility of obtaining both embryogenic and organogenic potential in two parts of the same explant simultaneously. The possibility of extending this approach for genetic transformation in in vivo system through direct DNA delivery or Agrobacterium injection in meristems can also be explored. Using Agrobacterium rhizogenes, we have demonstrated the possibility of gene transfer in the axillary meristems of seed-derived plumule explant.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.281-286
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• 1994

The hormonal regulation of organ differentiation was investigated in the tissue culture of sweet potato. Embryogenic callus was induced from shoot tips cultured on MS medium supplemented with 1 mg/L 2,4-D. When embryogenic callus was transferred to medium containing 0.1 mg/L GA$_4$, it proliferation was stimulated. The callus gave rise to plantlets when cultured on medium containing 0.1 mg/L BA. Addition of 0.1 mg/L jasmonic acid or 0.01 mg/L brassinolide to medium was effective for the development of healthy normal plantlets.

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.479-484
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• 2000

This study was conducted to examine the effects of explant sources and plant growth regulators on mass propagation of Cyclamen persicum. Tuber, cotyledon, and petiole tissues were cultured on MS medium supplemented with different concentrations and combinations of auxins and cytokinins. Shoots were not induced from calli on cotyledon and petiole explants cultured on MS medium containing various concentrations of 2,4-D or NAA. However, multiple shoots were formed directly from tuber explants cultured on the medium containing 0.5 and 1.0 mg/L 2,4-D or NAA. In MS medium with cytokinin alone, TDZ was more effective in shoot formation than BA or kinetin in all explants. The combinations of NAA and BA was found to be most effective in shoot formation from tuber, cotyledon and petiole explants. Especially, shoots were formed from all the tuber explants on the medium containing 0.5 mg/L of NAA and BA. Hormonal effects on root formation were examined by subculturing single shoots on MS medium containing NAA or IBA. The medium with 0.5 mg/L IBA was most effective in root induction and subsequent plantlet regeneration.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.684-694
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• 2018

This study describes the successful establishment of a cryopreservation protocol for Citrus limon cultivars: 'Frost Eureka limon' and 'Cook Eureka limon', using a droplet-vitrification method. The shoot tips that were excised from in vitro grown seedlings of the two cultivars were preserved in liquid nitrogen (LN) and successfully regenerated into whole plants. Excised shoot tips were pre-cultured for 1 or 2 days in 0.3 M and 0.5 M sucrose solutions at $25^{\circ}C$ and incubated in a loading solution (LS) composed of 17.5% glycerol + 17.5% sucrose in Murashige and Skoog (MS) medium for 40 min at $25^{\circ}C$. Prior to direct immersion in LN for 1 h, the shoot tips were dehydrated with plant vitrification solution 2 (PVS2) at $0^{\circ}C$ or PVS3 at $25^{\circ}C$. The frozen shoot tips were re-warmed and unloaded with 1.2 M sucrose in $\text\tiny{^1/_2}$ MS for 30 min at $25^{\circ}C$. Shoot tips were post-cultured overnight on survival medium and then micrografted onto 'trifoliate orange' (Poncirus trifoliate (L.) Raf. seedling rootstocks for recovery and to produce whole plants. The highest regrowth rates were 53.5% and 50.3% for cryopreserved shoot tips of 'Frost Eureka limon' and 'Cook Eureka limon', respectively, when pre-cultured in 0.3 M and 0.5 M sucrose concentrations in a sequencing manner, with LS and treated with PVS2 for 60 min at $0^{\circ}C$. We also investigated whether the ammonium ion concentration on post-culture medium affected the viability of the cryopreserved Citrus shoot tips. The viability of cooled samples, following culturing on woody plant media (WPM) containing $\text\tiny{^1/_4}$ ammonium nitrate overnight before micrografting, was the highest (70.3%) in 'Frost Eureka limon'. The study described here is a cost-effective and safe method to conserve Citrus fruit cultivars, for the improvement and large-scale multiplication of fruit plants and for breeding disease resistance.

• Journal of Plant Biotechnology
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• v.50
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• pp.82-88
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• 2023

Shoot-tip culture was used to produce clonal plants of radish stock seeds. Using 6-benzyladenine (BA), the largest number of RA2 line multi-shoots were formed with an average of 14.67 shoots on 1.33 µM BA in early seedlings and 11.33 shoots on 1.78 µM BA in juvenile seedlings. The largest number of RA4 line multi-shoots were formed with an average of 11.67 shoots on 2.22 µM BA in early seedlings and 13.67 shoots on 1.33 µM BA in juvenile seedlings. There was little difference in the significance level by BA concentration in both lines. Using Thidiazuron (TDZ), the number of RA2 line multi-shoots increased with increasing TDZ concentration, forming the largest number of multi-shoots in 0.45 µM TDZ (7.0 and 3.0 multi-shoots for early and juvenile seedlings, respectively), but few multi-shoots were formed from TDZ 2.25 and 4.5 µM. RA4 line produced almost no multi-shoots in early seedlings, and 3.7 multi-shoots were produced in 0.23 and 0.45 µM TDZ in juvenile seedlings, but not at higher concentrations. Analysis of the tissue culture seedlings grown by cultivating the generated multi-shoots with Radish Foundation seeds using SSR marker revealed a weak pattern of mutation in the generated tissue culture seedlings, but there was no mutant. In addition, in terms of root roots, both RA2 and RA4 lines generally had the best rooting, number of roots, and degree of root development in 4.9 µM indol-3- butyric acid (IBA).

• Journal of Plant Biotechnology
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• v.34 no.3
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• pp.263-269
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• 2007

To establish a optimum culture condition in vitro for production of seedlings in Wasabia japonica, the effects of salt strength, sucrose concentration, and $NH_4/NO_3$ ratio on the shoot growth in MS medium were investigated. The full strength of MS medium was the best condition for shoot growth, and in $1/4{\sim}1/2x$ or 2x MS medium the growth was significantly suppressed. Growth of shoots was enhanced when sucrose was added in MS medium after 2 weeks of culture, and the best result was found at 3% sucrose addition. ${NH_4}^+/{NO_3}^-$ ratio of 10:50 gave the highest biomass of shoot in the liquid culture with MS medium, and increasing the ${NH_4}^+$ ratio in the medium significantly reduced the growth of shoot.

• Korean Journal of Medicinal Crop Science
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• v.2 no.2
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• pp.154-161
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• 1994

This experiment was carried out to establish micropropagation system in Fritillaria thunbergii Miq. Through the culture of bulblet scales, stems, node-buds and shoot tips with special reference to the effect of physiological age of explant and plant growth regulators on bulblet formation. Number of formed bulblets was significantly increased in node-bud or stem tissue compared to scals segments and on the medium supplemented with kinetin than BA containing medium. Optimum levels of kinetin for bulblet formation from node-bud taken from above 3 cm shoot length and stem segments excised from below 3 cm shoot length were 5.0 mg /L and $1.0{\sim}3.0\;mg$ /L kinetin, respectively. Interesting phenomenon was observed, the direct formation of bulblets from the axilliary bud of cultured explants. Bulblet forming capacity in stem tissue was depended on stem age, young stem had high regeneration ability compared to old stem taken from above 10 cm shoot length. 1.0 mg /L kinetin was optimum concentration for the formation of bulblets from old stem segments. Stem tissue taken from underground growing plant was promoted coampare to shoot tips or bulb scale segments. Optimum concentration of sucrose was $5{\sim}7%$. Summariged above results revealed that effective explant for micropropagation was stem and /or node-bud tissue excised from less than 3 cm plant height compared to those of bulb scale segments which showed high contamination after culture. Maximum multiplication rate of young stem and /or node-bud segment was about 20 times. Kinetin requirement for stimulation of bulblet formation from cultured explant depended on source of explants but favorable levels of kinetin for organogenesis ranged from 1.0 mg /L to 5.0 mg /L.