• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.68-71
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• 1991

Mulberry cuttings from shoots of Shinkwangppong(Morus bombycis koidz.) had been callused in vermiculite separately at 15, 20, 25 and 30$^{\circ}C$ for 15 days before transplanting them in greenhouse to make clear the effect of temperature on root formation and growth is as follow. The buds of cuttings started sprouting in 4 and 6 days of callusing at 30 and 25$^{\circ}C$, respectively, reaching 100% budding in 10 and 15 days of callusing. Budding was delayed, however, at low temperature, showing 86% and 92% at 15 and 20$^{\circ}C$, respectively, in 15 days. Rooting from the cuttings was also accelerated at high temperature, showing 97-100% rooting at 25$^{\circ}C$ and 30$^{\circ}C$, in 15 days of callusing but no more than 93% at low temperature even in 35 days. Although high temperature increased root number and length after 15 days in callusing, no differences showed in the number and the weight at more than 20$^{\circ}C$ in 35 days of cuttings.

• Journal of Sericultural and Entomological Science
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• v.33 no.2
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• pp.63-67
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• 1991

Various concentrations of ${\alpha}$-naphthalence acetic acid(NAA) as a root-promoting substance were tested in hardwood cutting of the mulberry(Morus bombycis Koidz., cultivar : Shinkwangppong) to make clear the callusing effect on the budding and root growth. Budding and shoot growth of cuttings were delayed at high concentrations of NAA within 10 days of callusing. Especially more severe is it at higher than 50ppm. More than 93% of them, however, budded in two weeks when callused at less than 100ppm NAA. Although rooting was accelerated at high concentration of NAA from the bigining of cutting, after that, rooting percentage increased to reach 100% in 35 days of cutting in any concentration except 150ppm with relatively low rooting. Root growth was utmostly accelerated at 50ppm NAA to show the highest amount in number, length and weight of roots per cutting although high concentration of it decreased mean root length.

• ALGAE
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• v.24 no.3
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• pp.163-168
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• 2009

Grateloupia filicina (J.V. Lamouroux) C. Agardh (Halymeniaceae, Cryptonemiales, Rhodophyta) is an edible seaweed as well as an important source of carrageenan. In the present study, attempt has been made to develop a suitable protocol for effective regeneration of the seaweed and the rapid multiplication of the desired varieties. The young upright thallus of G. filicina was grown in axenic culture using both solid and liquid media. The various media tested were f/2, Provasoli’s Enriched Seawater (PES) and Enriched Seawater (ESW). The effect of glycerol (as a carbon source) and various plant growth regulators i.e. auxin (NAA) and cytokinins (Kinetin and BA) were tested. Although, regeneration of young thalli was observed from the cut ends in all the media, better growth was found in f/2, PES, f/2 (0.5% Glycerol), f/2 (NAA ${10^{-5}}_M)\;and\;f/2\;(BA\;{10^{-6}}_M$). On the other hand callusing was observed only in solid media supplemented with low concentration of Glycerol (0.5%) in f/2, NAA ${10^{-5}}_M\;in\;f/2,\;PES\;and\;BA\;{10^{-5}}_M$ in f/2. Young thalli were developed from the callus sub culture after 40 days of inoculation.

• Journal of Ginseng Research
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• v.27 no.1
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• pp.17-23
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• 2003

Agrobacterium-mediated transformation of American ginseng (Panax quinquefolius L.) with strain LBA 4404 containing a rice thaumatin-like protein gene is described. The selectable markers used were phosphinothricin acetyltransferase and hygromycin phosphotransferase genes. Epicotyl explants from seedlings were precultured for 5-7 days on Murashige and Skoog medium with ${\alpha}$-naphthaleneacetic acid and 2,4 dichlorophenoxyacetic acid at 10 ${\mu}$M and 9 ${\mu}$M, respectively (ND medium), prior to Agrobacterium infection. The explants were immersed in a bacterial suspension for 20 min. A post-infection co-culture period of 3-4 days was provided on ND medium. Selection for transformed calli was conducted on ND medium with 20 mg/L phosphinothricin followed by 100 mg/L hygromycin over an 8-month period. it transformation frequency of 24.8% was achieved at the callusing phase. The presence of the transgenes in calli was confirmed by Southern hybridization and polymerase chain reaction analysis. The expression of the thaumatin-like protein gene in ginseng calli was demonstrated by Western blot analysis. Somatic embryos were produced from both transgenic calli and suspension cultures, and plantlets were recovered that expressed the transgenic thaumatin-like protein gene.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.43-50
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• 2006

The goal of this research was to develop an efficient cryopreservation protocol for germplasms of yam (Diosorea batatas), that were cultivated in Korea. Comparative studies with four other cryogenic techniques and subsequent experiments for shoot regrowth were conducted. in vitro-grown shoot-apices of the D. batatas were successfully cryopreserved by encapsulation-dehydration. The maximum survival of shoot-apices could be achieved when the precultured (with 0.3 M of sucrose for one day) and encapsulated (with a 3%(w/v) Na-alginate solution) apices were dehydrated for $3.5{\sim}4\;h$ prior to direct immersion in LN (liquid nitrogen). The frequency of regrowth rate of cryopreserved apices was not decreased during 3-month storage period. The thawing method markedly affected survival of the cryopreserved apices, and thawing at $40^{\circ}C$ for 3 min produced the best results. When cryopreserved apices were post-cultured on the post-culture medium (MS), supplemented with $0.2mgl^{-1}$ of BA ($N_6$-benzyladenine) and $0.2mgl^{-1}$ of kinetin, they showed direct shooting without callusing.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.1
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• pp.51-55
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• 2001

This study was conducted to establish a plant cell culture system for the production of medically important secondary metabolites from Xanthium strumarium. The effects of plant growth regulators including NAA, 2,4-D, kinetin, and ABA were examined in terms of callus induction, maintenance of callus and suspension cultures. It was shown that callus was induced upon treatment with NAA while embryo was induced after treatment with 2,4-D. Callus formation was further improved by treatment with ABA and NAA. The level of callusing increased by 17-29% for the seed case, cotyledon, leaf, and hypocotyl and by 96% in the case of the root. Suspension cell lines were established using calli produced from cotyledon, hypocotyl and root and cultured at 25$\^{C}$ under light conditions. The cells grew up to 15g/L with NAA 2ppm, BA 2ppm, and ABA 1ppm treatment. Supernatants of suspension cultures of cell lines derived from coyledon and hypocotyl produced some distinctive secondary metabolites, one of which was identified as 8-epi-tomentosin, which belongs to the xanthanolides. The amounts of 8-epi-tomentosin produced by the cotyledon- and hypocotylderived cell lines were 13.4mg/L and 11.0mg/L, respectively.

• Horticultural Science & Technology
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• v.29 no.3
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• pp.260-266
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• 2011

An efficient protocol was established for high frequency somatic embryogenesis through a callus culture of Coelogyne cristata. The best frequency of callusing was obtained from a PLB segment (3-5 mm) cultured on MS medium supplemented with coconut water (CW) and a combination of both 3 $mg{\cdot}L^{-1}$ of 2,4-D and BA. When the calli were sub-cultured on the MS medium without any PGRs, the average number of somatic embryos were higher than those with PGRs treatment. NAA is the most critical factor among PGRs, which dramatically hindered for the formation of a somatic embryo. The efficacy of the addition of coconut powder (CP) for somatic embryogenesis was almost the same in all treatments. However, the number of somatic embryos formed distinctly depended on age of the callus. The somatic embryos converted into healthy plants with well-developed shoots on the same medium. Plantlets showed the best responses of root and shoot growth when transferred to $\frac{1}{2}$ MS medium containing 1.5 $g{\cdot}L^{-1}$ of activated charcoal. All plants with above 3.0-cm-high were successfully acclimatized in the greenhouse.

• Korean journal of applied entomology
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• v.4
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• pp.7-10
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• 1965

In an experiment to evaluate the various aspects of symptom of witches' broom of jujube tree with two different kinds of scions, taken from diseased plant and stem- grafted upon sound stocks-one cut before wintering(stored in cellar), the other after wintering, it was observed that the disease rate of those cut before wintering(Nov.) was $\98\%$ whereas those cut after wintering(March) showed much lower rate, $3\%$ initially and gradually increased up to $39\%$. In another experiment of diseased bud grafted into healthy seedling, the finding made in the following year was that 14 stocks(only one of which salt union by callusing) were infected out of the given 23- in the initial stage only 4, yet gradually increased to the number of 14. The shoots from the ground portion of the diseased stock were in general more quickly subjected to the disease than the others. Under natural condition, the diseased trees develop at first seemingly the same leaves as healthy ones; it is not until the branches and loaves grow to a considerable degree that the symptom appears. Once appearing, tile disease grows and the symptom continues to appear as late as in Sept. and early Oct., causing tile plant to develop the extraordinary branches and leaves of extremely reduced size, the typical symptom of witches' broom. Such phenomenon can be observed in the experiments of the foregoing paragraphs. And the suckers and roots of diseased plant are bound to be infected, it was found out with no exception. Viewing from the results of the above experiments and observation, it is believed that the low temperature during winter causes the virus in the above-ground portion of diseased plant to diminish or inactivated, and subsequently the virus in the roots moves up or multiply in the sprouting season.

• Journal of Plant Biotechnology
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• v.45 no.1
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• pp.55-62
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• 2018

In the present study in vitro mutagenesis was used to study the effect of gamma irradiation and EMS on callus induction, morphogenesis and production of multiple shoots from different explants of Citrullus colocynthis (L.) Schrad. Gamma radiations (5 kR to 20 kR) and certain chemicals have been effected on plant growth developments and changes of biochemical metabolisms in plants. Murashige and Skoog (MS) medium containing with auxins such as NAA, IAA, 2,4-D (0.5 ~ 2.0 mg/l), cytokinines BAP, kn TDZ, (0.5 ~ 2.5 mg/l), L-Glutamic acid (1 ~ 2 mg/l) and Coconut milk (10 ~ 20%). After 5 weeks on induction media, explants and callus (EC) were exposed to 5 kR, 10 kR, 15 kR and 20kR, of gamma radiation and treated with 1, 2, 3, 4 and 5 mM ethyl methane sulphonate (EMS) for 30 min. The highest percentage of callusing was observed (70%) stem irradiated with 5 kR and significantly decrease in fresh and dry weight of callus in the below 4 kR doses and above 20 kR doses, there was a progressive decrease in the fresh weight and dry weights when compared to control callus. Maximum percentage of plantlet regeneration (59%) was induced from callus exposed to 15 kR gamma irradiation on MS media fortified with 2.0 mg/l 2,4-D + 2.0 mg/l BAP + 2.0 mg/l L-glutamic acid. Increase in gamma irradiation dose above 15 kR and 5 mM EMS reduced regeneration capacity of callus. Doses higher than 20 kR and 7 mM EMS was lethal to micropropagated plants of Citurullus colocynthis.

• Korean Journal of Plant Tissue Culture
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• v.26 no.2
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• pp.85-91
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• 1999

In sweet potato cultivars 'Mokpo #29' and 'Sanchunza', shoots from extplants were formed 100% on the MS medium with 0.1 ㎎/L NAA and 2.0 ㎎/L BA after 30 days of culture and roots produced from the base of stem at frequencies of 66.7% ('Mokpo #29') and 69.2% ('Sanchunza'), respectively, The media with 0.5∼4.0 ㎎/L BA were produced the greatest frequency of multiple shoot and the most of shoots developed rapidly into normal plantlets with rooting within 60 days of culture. Whereas the cultivar 'Keumsi' failed to produce normal shoot multiplication on the medium with cytokinins alone because of callusing of adventitious shoots. When single shoots with 1 to 2 nodes were excised from the multiple shoot or shoots covered with callus devoid of root and transferred to MS medium with 4.0 ㎎/L BA or kinetin. Host divided shoots showed the callus induction at the stem base and it was enable to obtain regenerated plantlets with shoot and root normally.