• Journal of Plant Biotechnology
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• v.29 no.1
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• pp.45-49
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• 2002

The leaf and petiole segments of Farfugium japonica were cultured to investigate the influence of growth regulators on their callus induction and plant regeneration. The callus induction and growth showed a good response both leaf and petiole on MS media supplemented with 1∼2 mg/L 2,4-D and 1∼2 mg/L BA. Callus induction and growth were more effective in petiole segments than leaf one. The highest percentage of plant regeneration was obtained from 60-day-old calli on MS medium supplemented with 1 mg/L NAA and 2 mg/L BA. When subcultured to the same medium for about 60 days, multiple shoots were developed from regenerating callus. The shoots produced roots after transferring to rooting medium containing 0.5 mg/L IAA. The plantlets over 50 mm in height were successfully acclimatized in vermiculite, and the survival rate was over 95%.

• Journal of Plant Biology
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• v.31 no.1
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• pp.41-49
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• 1988

Several cultivars of rice were examined for induction of embryogenic callus on a medium containing MS salts, vitamins and 2, 4-D under darkness. Embryogenic callus was obtained from cultivar Cheonma with high ratio and embryo-like structures were formed from the callus on a medium with or without reduced 2, 4-D. Somatic embryoids with a plumule and radicle axis surrounded by a scutellum were observed. These embryoids germinated and produced plantlets in 30 days on the same medium. Protoplasts isolated from an embryogenic cell suspension culture derived from embryogenic callus were cultured either in liquid or in agar medium and protoplast derived cell colonies were obtained in 3-4 weeks.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.80-80
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• 2018

Hosta is a genus of the family Asparagaceae and distributed in East Asia. There are six Hosta species (Hosta capitata (Koidz.) Nakai, H. clausa Nakai, H. jonesii M.G.Chung, H. minor (Baker) Nakai, H. venusta F.Maek., and H. yingeri S.B.Jones) native to Korea and among them, four species (H. minor, H. jonesii, H. venusta and H. yingeri) are endemic to the Korea peninsula. Hosta is generally propagated by seed, crown division or tissue culture. However, tissue culture is a more efficient method to mass proliferation, a new cultivar development and disease-free plantlet production in a limit time. Hence, we conducted this study to evaluate the influence of various plant growth regulators (PGRs) treatments on the induction of callus and somatic embryo of the six Hosta species. Leaf, petiole and root were used to select optimum tissue culture explants. Petiole explants thus only were used for callus induction and somatic embryogenesis with TDZ (0.1, 0.5 or 1.0mg/L) and NAA (0.1 or 0.5 mg/L) combinations. After 12 weeks of culture, the highest rate of somatic embryogenesis was achieved on modificated MS medium containing 1.0 mg/L TDZ and 0.1 mg/L NAA in H. capitata and H. minor (15.5%, respectively), 0.1 or 0.5 mg/L TDZ and 0.1 mg/L NAA in H. jonesii (22.2%), 1.0 mg/L TDZ and 0.5 mg/L NAA in H. yingeri (26.7%), and 0.1 mg/L TDZ and 0.5 mg/L NAA in H. venusta (53.3%). H. clausa showed very low effect on somatic embryogenesis by PGRs; 2.2%. There was interspecies difference to PGRs respond for callus and somatic embryo induction. Regenerated multiple shoots and plantlet of H. minor, H. jonesii, H. venusta and H. yingeri were obtained via somatic embryogenesis.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.263-266
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• 1998

Flowergenic callus was induced from the ovary surface of Allium fistulosum L. cultured on MS medium containing 0.5mg/L NAA and 0.5mg/L BA or 0.5mg/L kinetin. After 3-4 weeks of culture, the flower buds were developed from flowergenic callus. The continuous production of flowergenic callus was proliferated, when subcultured on the medium containing 0.5mg/L NAA and 0.5mg/L kinetin. However, frequency of flower bud formation from flowergenic callus was decreased as the subculture was repeated. Histological observation reveals that the developmental pattern of flower bud from flowergenic callus was closely similar to that of natural flowers.

• Journal of Plant Biotechnology
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• v.35 no.2
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• pp.133-140
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• 2008

The modification of DNA and histone plays an important role for gene expression in plant development. The objective of this research is to observe the effects of methylation on the gene expression during dedifferentiation from rice mature seeds to callus and differentiation from callus to shoots. The embryogenic callus with ability to shoot regeneration was not induced on the N6A medium supplemented with 5-azacytidine and abnormal callus with brown color was formed. When the normal rice callus was placed on the regeneration MSRA medium supplemented with 5-azacytidine, the shoot regeneration was inhibited. The results showed that 5-azacytidine, DNA demethylating agent, had negative effects on normal embryogenic callus formation and shoot regeneration. This suggested that DNA methylation of some genes was required for normal cell dedifferentiation and differentiation in tissue culture. The microarray and $GeneFishig^{TM}$ DEG screening were used to observe the gene transcript profile in callus induction and regeneration on N6A (N6 medium + 5-azaC) and MSRA (MS regeneration medium + 5-azaC). Subsets of genes were up-regulated or down-regulated in response to 5-azaC treatments. The genes related with epigenetic regulation, electron transport, nucleic acid metabolism and response to stress were up and down regulated. The different expression of some genes (germin like protein etc.) during callus induction and shoot regeneration was confirmed using RT-PCR and northern blot analysis.

• Korean Journal of Food Science and Technology
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• v.14 no.2
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• pp.179-183
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• 1982

This experiment was carried out to clarify the optimal concentrations of growth regulators for callus induction and the condition of callus culture of leaf tissue taken from Stevia rebaudiana Bertoni. The content of stevioside, sweetening component, in leaf-derived callus of stevia was also investigated. It was shown that the optimal concentrations of benzyladenine (BA) and ${\alpha}-naphthalene$acetic acid (NAA) for callus induction were $10^{-6}M$ and $10^{-5}M$, respectively. Reculture of these calli in media (Linsmaier and Skoog) supplemented with BA $10^{-6}M$ and NAA $10^{-5}M$ resulted in profuse calli 15 to 20 days after incubation. When sweetening components produced by callus were extracted and identified by TLC, stevioside appeared to have Rf value 0.50 in TLC which was exactly same as standard stevioside. Stevioside content obtained by TLC-FID analyzer was 260mg per 100g on the basis of dry weight.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.37-45
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• 2007

The genetic transformation of watermelon by Agrobacterium has been known very difficult and a few successful cases have been reported by obtaining the direct shoot formation. However, since this direct shoot formation is not guaranteed the stable transformation, the stable transformation with reproducibility is required by a different approach such as a callus induced manner. The best conditions for inducing the callus from cotyledon and root explants of watermelon were 2 mg/L zeatin + 0.1 mg/L IAA and 2 mg/L BA + 0.1 mg/L 2,4-D, respectively. The GFP expression in the callus was identified and monitored through fluorescent microscopy after transformation with pmGFP5-ER vector. Paromomycin rather than kanamycin was used for selecting the nptll gene expression because it was more effective to select the watermelon explants. Four different callus types were observed and the solid green callus showed stronger GFP expression. The highest frequency of GFP expression in the callus developed from cotyledon was 9.0% (WM8 inbred line), while the highest frequency from root was 8.3% (WM6 inbred line). The WMV-CP was transformed using the method of GFP transformation and the genetic transformation of WMV-CP was confirmed by PCR and Southern blot analysis. Here we present a system for callus induction of watermelon explant and the callus induced method would facilitate the establishment of stable watermelon transformation.

• Molecules and Cells
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• v.23 no.3
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• pp.323-330
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• 2007

The mature wheat embryo is arguably one of the best explants for genetic transformation because of its unlimited availability and lack of growth season restriction. However, an efficient regeneration system using mature wheat embryos (Triticum aestivum L.) is still not available. To identify genes related to the tissue culture response (TCR) of wheat, QTLs for callus induction from mature embryos and callus regeneration were mapped using an RIL population derived from the cross of 'Wangshuibai' with 'Nanda2419', which has a good TCR. By whole genome scanning we identified five, four and four chromosome regions conditioning, respectively, percent embryos forming a callus (PEFC), percent calli regenerating plantlets (PCRP), and number of plantlets per regenerating callus (NPRC). The major QTLs QPefc.nau-2A and QPcrp.nau-2A were mapped to the long arm of chromosome 2A, explaining up to 22.8% and 17.6% of the respective phenotypic variance. Moreover, two major QTLs for NPRC were detected on chromosomes 2D and 5D; these together explained 51.6% of the phenotypic variance. We found that chromosomes 2A, 2D, 5A, 5B and 5D were associated via different intervals with at least two of the three TCR indexes used. Based on this study and other reports, the TCRs of different explant types of wheat may be under the control of shared or tightly linked genes, while different genes or gene combinations may govern the stages from callus induction to plantlet regeneration. The importance of group 2 and 5 chromosomes in controlling the TCRs of Triticeae crops and the likely conservation of the corresponding genes in cereals are discussed.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.273-278
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• 2002

Several regenerated plants were obtained from anther culture of the hybrid lines of Italian ryegrass (Lolium multiflorum Lam.) X Tall fescue (Festuca arundinacea Schreb.). When the anthers of the hybrid plants were incubated for 20 days on callus induction medium, MS medium containing 30 g/$\ell$ of sucrose, 2 mg/$\ell$ of NAA and 1 mg/$\ell$ of kinetin, their calli were induced. The mean ratio of callus induction was 11.6 percent, and the mean of callus weight was 9.1 mg/callus/anther. When the calli of the hybrid plants were incubated for 50 days on plant regeneration medium, MS medium containing 30 g/$\ell$ of sucrose, 1 mg/$\ell$ of NAA and 2 mg/$\ell$ of kinetin, the hybrid plants were regenerated. The mean ratio of plant regeneration was 27.1 percent and line Hyb-1 showed highest regenerabillity with the frequency of 30.2 percent.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.3
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• pp.165-170
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• 2008

Timothy (Phleum pratense L.) is an important grass species as forage. In order to optimize tissue culture conditions of timothy, the effects of plant growth regulators on callus induction and plant regeneration was investigated with mature seeds of colt cultivar. The optimal concentration of 2,4-D for the induction of primary callus from mature seeds was 3 mg/L. The highest embryogenic callus frequenc (25%) was observed when the mature seed were cultured on MS medium supplemented with 3 mg/L 2,4-D and 0.1 mg/L BA. The highest plant regeneration frequency was observed when type B callus was transferred to N6 medium supplemented with 1 mg/L 2,4-D and 3 mg/L BA. Regenerated plants were grown normally when shoots were transplanted to the soil. A short tissue culture period and regeneration system would be beneficial for molecular breeding of timothy by the production of transgenic plant.