• Journal of Plant Biotechnology
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• v.7 no.3
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• pp.169-174
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• 2005

The optimal culture conditions were studied for plant regeneration from mesophyll protoplasts of Solanum sisymbriifolium. Axenic seedlings of S. sisymbriifolium were used as a explant for protoplast culture. Many viable protoplasts were isolated by incubating leaf slices in an enzyme solution containing 0.25% Meicerase and 0.05% Macerozyme for 16 hr at $25^{\circ}C$ without shaking. Protoplast density of $5.0{\times}10^4\;ml^{-1}$ in Kao medium containing 5.0 mg/L NAA, 1.0 mg/L 2,4-D and 1.0 mg/L BA was optimal for colony formation. Most colonies were formed when protoplasts were cultured at $25^{\circ}C$ after initial culture at $30^{\circ}C$ for one week. On the MS agar medium with 1.0 mg/L zeatin, 38.4% of protoplast-derived calli differentiated shoots. These shoots rooted on 1/2MS medium with 5.0 g/L sucrose and 2.5 g/L gellan gum, and developed into whole plants.

• Plant Resources
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• v.2 no.2
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• pp.65-68
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• 1999

This study was conducted to obtain the basic breeding information of Colocasia esculenta Schott. Effect of supplemental plant growth regulators and genotype difference were investigated on dormant bud tissue for proliferation. The plant regeneration ratio, plant height and root length were the best upon mixed treatment of 0.8mg/L IAA and 2.0mg/L zeatin. Both leaf weight and root weight were heavy upon culture in a dark condition. The leaf and root weights were heaviest in 6Pie sucrose concentrations. In several collected area the heaviest one was Binnangxin and then in the order of Suwon, Wanju and Puan. Genotype differences of tuber diameter and tuber weight were found in Suwon. Tuber weight was found in the order of Suwon (862mg) >Wanju(723mg) >Puan(649mg) >Binnangxin (424mg).

• Plant Resources
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• v.7 no.1
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• pp.1-6
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• 2004

In vitro proliferation system was achieved by using nodal segment excised from greenhouse grown juvenile stock plants of Alnus japonica. Stem explants were cultured on MS medium supplemented with different plant growth regulators of cytokinin and/or their combinations. The most effective cytokinin source was the combination of zeatin 2.0 mg/L and TDZ 0.05 mg/L producing the average number of shoots (16.8 $\pm$ 3.6). In addition, healthy roots were formed after small clumps of shoots were transferred to half strength of MS medium containing IBA 0.02 mg/L with optimal rooting capacity. Soil acclimatization was successfully conducted in cell tray containing artificially mixed soil with 92 % survival rate.

• Korean Journal of Weed Science
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• v.9 no.1
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• pp.56-68
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• 1989

aA series of experiments were conducted to investigate the effect of plant growth regulator treatments on the growth and lateral root formation in soybean sprouts in order to establish the effective method of producing root-less or short-rooted soybean sprouts with larger diameter in the hypocotyl. Major results can be summarized as follows. 1. Soybean sprouts showed fairly uniform elongation rate from 3 to g days after imbibition with daily increase of 3.8cm. The speed of elongation of hypocotyl was reduced whereas that of root accelerated 7 days after imbibition. Lateral roots began to emerge fairly evenly from 5 to 9 days after imbibition with a daily increase of 4.4. 2. Auxins(IAA, IBA, NAA, 2,4-D) inhibited hypocotyl elongation and formation of lateral roots and increased hypocotyl diameter without influencing root length and hook diameter at higher concentrations. The dry weight of cotyledon was increased significantly as compared to that of hypocotyl and root. Among the tested auxins, 2, 4-D was the most effective. 3. BA and 4PU-30 significantly reduced elongation of hypocotyl and root and resulted in the biggest diameter of hypocotyl when treated at higher concentrations. The lowest effective concentration of BA to prevent the formation of larval gal roots was 12.5ppm. The formation of lateral roots could be completely prevented by BA and 4PU-30 treatment but kinetin, zeatin, zeatin riboside resulted in many lateral roots and increased thickness of soybean sprouts with little influence. Cotyledon deformation was found in soybean sprouts treated by 4PU-30. 4. 2, 4-D was the most effective for increasing the hypocotyl diameter while 4PU-30 was the most effective for reducing no. of lateral roots. 5. It can be concluded that among the plant growth regulators tested, BA was effective in reducing root length and increasing hypocotyl diameter. BA 12.5 ppm or 15 ppm may thus be the more practical for production of soybean sprouts. 6. ABA showed no significant effect of growth parameter, however ABA 25 ppm inhibited only no of lateral roots with little influence on the growth of seedling. 7. Ethephon inhibited the elongation of hypocotyl and root and increased hypocotyl diameter at higher concentrations. 8. The combined effect of cytokinins and ethephon was very similar to result of BA treatment alone. As the ethephon concentration increased, hypocotyl diameter and dry weight of cotyledon tended to increase.

• Journal of Plant Biotechnology
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• v.50
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• pp.155-162
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• 2023

Radish (Raphanus sativus L.), a root vegetable grown worldwide, is consumed in several ways. In the cross between parental lines to produce F1 seeds of radish, the problem of low purity may arise because of pollen contamination. Therefore, we aimed to establish conditions for callus induction and regeneration so that in vitro cultured plants could be used for the propagation of stock seeds. The most effective hormone combination containing various concentrations of 2,4-D, TDZ, and kinetin was selected for callus induction using radish hypocotyl, and the induced calli were transferred to two types of hormone media to investigate the optimal conditions for shoot regeneration of the callus. The combination of 1 mg/L 2,4-D + 0.05 mg/L kin was the most effective for callus induction of RA2 and RA10, 1 mg/L 2,4-D + 0.1 mg/L kin + 0.025 mg/L TDZ of RA4, and 1 mg/L 2,4-D + 0.2 mg/L kin of RA30. Shoot regeneration of the RA4 callus occurred in both shoot regeneration media, but the frequency was much higher in the 5H+1B medium (1 mg/L NAA + 0.1 mg/L 2,4-D + 1 mg/L IPA + 0.02 mg/L GA3 + 2 mg/L zeatin + 1 mg/L BA). For the in vitro micropropagation of radish, the conditions selected in this study can assist in the propagation and maintenance of stock seeds to produce F1 seeds.

• 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 $1,555{\mu}g$.

• Journal of Plant Biotechnology
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• v.44 no.2
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• pp.171-177
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• 2017

A callus-mediated regeneration protocol for sea-milkwort, an endangered coastal plant species in South Korea, is reported here. The explants of in vitro-plantlets generated from a node culture revealed distinguishable responses in callus induction depending on genotype, explant source, light condition, and 2,4-D concentration. Especially, continuous darkness exclusively facilitated callus induction from explants prior to other treatments. The calli initiated on the media with 2,4-D ranging from 0.1 mg/L to 3.0 mg/L in the dark vigorously proliferated when subcultured on the same media in continuous darkness. Given 1.0 mg/L zeatin in addition to darkness to the calli of the 'Pistachio' genotype, normal adventitious shoots were only regenerated from nodular structures that formed earlier from the calli at the frequency of 24.4 percent. Regenerated shoots easily grew into plantlets with roots and green color on a phytohormone-free MS medium under lighted condition, that were used for node culture as plant materials. Node culture effectively multiplied plantlets in accordance with protocol by Bae et al. (2016). Acclimatized plantlet clusters developed mature plant clusters under inland environment, followed by flowering the following April. Results were merged with node culture protocol suggested by Bae et al. (2016), which, as an in vitro propagation system for sea-milkwort, may contribute to natural habitat restoration.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.49-55
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• 2017

We investigated the callus induction and plant regeneration ability of 16 maize genotypes, including the Korean inbred lines, using 9 to 15 day-old immature zygotic embryos from maize grown in pots and from field cultures. Immature zygotic embryos placed on MS medium supplemented with L-proline 0.7 g/L, MES 0.5 g/L, Dicamba 1.5 mg/L, 2,4-D 0.5 mg/L, $AgNO_3$ 4 mg/L, and sucrose 20 g/L, showed the highest frequency of callus induction. The highest number of shoots regenerated when the embryogenic callus were transferred to MS medium supplemented with 5 mg/L zeatin. The root formation was observed when shoots were grown on MS medium supplemented with 0.2 mg/L indole-3-butyric acid (IBA). Additionally, under the same culture conditions, immature zygotic embryos from maize grown in the field also had a high frequency of plant regeneration. Except one genotype, 15 genotypes showed callus induction and shoot regeneration. Among the 16 genotypes tested, H99, B98, HW3, and B73 yielded the best plant regeneration. H99 showed maximum shoot formation from the primary embryogenic callus. The results suggest that genotypes and growth conditions of the maize plant plays very important roles for enhancing the embryogenesis competence of immature zygotic embryos. The successful regeneration from immature zygotic embryos of maize inbred lines provides a basis for molecular breeding of new cultivars by genetic transformation.

• Journal of Plant Biotechnology
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• v.35 no.3
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• pp.235-243
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• 2008

Here we describe a procedure for Chinese cabbage protoplast culture and effects of various treatments. Chinese cabbage protoplasts were isolated from different parts of young seedlings as using an enzyme mixture, of which yield was maximized in seven hours around after digestion. The highest rate of initial cell division followed by micro-callus formation was obtained in the medium with 1.0 mg/L 2,4-D, 0.5 mg/L NAA, and 1.0 mg/L BA when the cotyledon-derived protoplasts were cultured. Initiation of cell division and micro-callus proliferation significantly depended upon Chinese cabbage genotype under a same culture circumstances. The micro-calli developed from cotyledon tissue of Norang-Bom cultivar successfully grew toward callus colonies on the solidified medium with 0.2 mg/L zeatin and 0.1 mM spermidine. The callus colonies generated de novo shoots at the maximum frequency of 4.3% on the medium with 5.0 mg/L BA and 1.0 mg/L NM. Our results might be helpful for further studies to enhance the regeneration efficiency in Chinese cabbage protoplast culture.

• Korean Journal of Plant Tissue Culture
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• v.22 no.5
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• pp.261-266
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• 1995

This study was carried out to develop new varieties which are dwarf and tolerant to winter cold in the Aurantioideae by intergeneric crossing. to do that, the reciprocal crosses of Hwanggeumyooza and trifoliate orange, yooza and trifoliate orange were done and in vitro immature ovule culture of their hybrid was carried out .The callus formation from immature ovule was good in order of Hwanggeumyooza, Hwanggeumyooza $\times$ tifoliate orange, yooza, and trifoliate orange and best at 1 to 3 mg/L NAA+0.5mg/L zeatin on MT medium. In vitro germination percentage of 20week old hybrid of Hwanggeumyooza $\times$ tifoliate orange and trifoliate orange $\times$ Hwanggeumyooza were 41.3% and 37.7, respectively. The phenotype of hybrid (95%) of Hwanggeumyooza $\times$ trifoliate orange and that (100%) of trifoliate orange $\times$ Hwanggeumyooza were similar to that of trifoliate orange. After Hwanggeumyooza was pollinated by pollens of trifoliate orange, the pollen tubes grew on stigma after 3h of pollination and entered into micropyle after about 24~28 h. One gamete in pollen was fused with polar nuclei after 2 days and other one fused with egg nucleus at 3days after pollination. The fruit set percentage by intergeneric crossing was 14.0% in Hwanggeumyooza $\times$ trtfoliate orange and 17.5% in trifoliate orange $\times$ Hwanggeumyooza. The fruit set percentages of Hwanggeumyooza. and trifoliate orange were 34.2% and 39.5% by artificial self-fertilization, 34.2% and 39.5% by artificial cross fertilization, 3.1% and 1.4% by parthenocarpy and 13.0% and 3.0% by natural fertilization, respectively. The somatic and gametic chromosome numbers of Hwanggeumyooza, yooza, and trifoliate orange were 2n=18 and n=9.