• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.304-308
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• 1993

A platelet activating factor(PAF) antagonist ginkgolides produced from Ginkgo biloba are well known for their potential usage in septic shock and other PAF related diseases. Even though they are extracted from the leaves and on occasion the root bark, the exact biosynthetic site and pathway have not proved yet. In order to locate the enzymes involved and elucidate the biosynthetic site of the compounds, embryo-derived aseptic intact plantlet and plantlet without root have been cultured on 0.3% active carbon-containing solid Murashige and Skoog's medium. The leaves from the six-week-old normal plantlet contained similar amount of ginkgolide B to that of outdoor plant leaves, while the plantlets without root had less than 30% of the ginkgolide B compared to the in vitro intact plantlets. The results suggest that the ginkgolides may be synthesized in the root and transported to the aerial part.

• Journal of Life Science
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• v.6 no.1
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• pp.40-47
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• 1996

Experiments were conducted to determine the effects of plant growth regulators on in vitro flowering and micropropagation of Gentiana scabra Bunge which had been used the cut flower, pot flower ornamental and medicinal plants. Flower bud formation was affected by GA$_{3}$ and kinetin. The optimum concentrations for flower bud formation was observed at 0.5 mg/l kinetin and GA$_{3}$ , while kinetin was favorable. More flowerings result from the interaction of GA$_{3}$ and kinetin at in a combination of 0.1 mg/l kinetin + o.1 mg/l GA$_{3}$, but the optimum concentration of GA$_{3}$ and kinetin was decreased. All concentrations of kinetin with 0.1 mg/l GA$_{3}$ or O mg/l GA$_{3}$ + 0.5 mg/l kientin reduced t (weeks needed for 50% plantlets). The plantlet growth was affected by GA$_{3}$ and kinetin during plantlet culture. More lateral shots and better shoot length per plantlet were obtained as GA$_{3}$ and kinetin concentration were increased up to 1.0 mg/l. The number of per plantlet was greater increased in MS medium containing GA$_{3}$ than kinetin. Interaction was exhibited at lower concentration with 0.5mg/l GA$_{3}$ and kinetin, but not in higher concentration with 1.0 mg/l GA$_{3}$ and kinetin. Higher pod diameter increased seed germination, while lower pod diameter was obtained from abnormal plantlet. MA medium containing 0.5 mg/l GA$_{3}$ significantly increased germination without regard to pod diameter.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.26-39
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• 2020

In maize, immature embryos (IEs) are highly regenerative explants most suitable for producing high frequencies of plantlet regeneration in vitro. Apart from media, explants, and hormones, genotypic variation also influences in vitro characters to a great extent. In the present study, IEs were used to study the distinctive effect of variation of size/stage and hormones in different genotypes on five in vitro characters viz., frequency of callus induction, growth rate of total callus, frequency of E. callus induction, and volume and number of regenerated plantlets. LS medium with different concentrations of 2,4-D (0.5, 1.5, 2.5, 4.0 and 5.0 mg/L) were used to study the former four in vitro characters, and medium with 6-benzylaminopurine and kinetin (0.5 mg/L, each) was used for plantlet regeneration. IEs of 1.0, 1.5, 2.0, 2.5 and 3.0 mm in size were isolated from four inbred lines viz., NM74C, NM81A, NM5883 and NM5884. Two-way ANOVA revealed that explant size and genotypes, as well as hormonal concentrations showed significant effects on in vitro characters. Two millimeter IEs were found to be suitable for in vitro cultures. LS medium with 1.5 mg/L 2,4-D and LS with BAP and Kn (0.5 mg/L, each) were found to be the best hormonal concentrations for callus induction, maintenance, and regeneration, respectively. Among the four genotypes, NM81A and NM5883 yielded more non-embryogenic and Type I E. calli. In contrast, NM74C and NM5884 yielded more highly regenerative Type II calli. Inbred line NM5884 was found to be the best among these four genotypes.

• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.431-437
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• 2017

Mulberry (Morus sp.) of the family Moraceae is very economically important in Asian countries including Korea, because its leaf and fruit have been commercially used in sericulture and horticultural industries. Therefore it is necessary to develop the optimal production system for rapid and cost-effective propagation of mulberry. Our studies focused on establishing an acclimatization method for the successful plantlet production of new cultivar 'Cheongsu' which was transferred ex vitro after in vitro culture. In particular, effect of abscisic acid (ABA) addition into the last subculture medium on plantlet response to subsequent ex vitro transfer and its growth was investigated. During acclimatization, stomatal conductance and transpiration rate of ABA-pretreated plantlets were significantly lower than those of non-treated plantlets. Net photosynthetic rate of ABA-pretreated plantlets decreased after ex vitro transfer but increased after 14 days, and it was mostly higher than that of non-treated plantlets. Moreover, relative water content as well as chlorophyll contents and its ratio were also higher in ABA-pretreated plantlets. On the other hand, proline was considerably higher than in control plantlets. After 1 month of ex vitro transfer, survival rate of ABA-pretreated plantlets was 85.6%, which increased by 29.1% in comparison with control (56.5%). More vigorous growth was also observed in ABA-pretreated plantlets. From these results, it was found that application of ABA to the last subculture medium could improve acclimatization and promote survival of mulberry plantlets after ex vitro transfer, inducing water stress tolerance and alleviating abiotic stresses.

• Journal of Plant Biotechnology
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• v.44 no.3
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• pp.320-324
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• 2017

Development of modern agricultural machinery and accompanying agricultural development cause soil compaction and reduce growth by stressing roots. Kalanchoe pinnata was used to investigate the impact of stress on rooting and changes in plant growth and reproduction. K. pinnata forms somatic embryos capable of asexual reproduction at the edge of leaves. Impact of root pressurization of K. pinnata on somatic embryogenesis and organ differentiation according to external stress factors was investigated by using a high concentration of agar and this phenomenon was studied histologically. Agar concentration in culture media ranged from 0.5%-1.5% to induce a compression effect on roots. The stem and leaf of K. pinnata were subjected to a microtechnique process to study changes in tissue. In vivo, K. pinnata produced 2nd and 3rd plantlets at edges of leaves from lack of water and excessive lighting conditions. In in vitro culture studies, the lower the concentration of agar, the higher the population and the higher the biomass, but plantlet did not occur in leaf bends. Conversely, as concentration of agar increased, increase in the number of individuals was low. Plantlet development occurred only in agar 1.5% medium. The difference in agar concentration was a stressor in the root of K. pinnata, and thus the pattern of asexual reproduction changed from the division method in root to a plantlet generation in leaf. This suggests root pressurization may act as stress and change in the plant reproduction pattern.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.259-266
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• 2009

A plantlet regeneration protocol was developed on pot-grown mature plants of Elaeocarpus robustus Roxb. cv. Dwarf from nodal and leaf explants. The best yield of adventitious shoots was achieved from the leaf-derived calli in a modified MS ($MMS_1$, half strength of major salts, full strength of minor salts, and vitamins) medium containing $4.0{\mu}M$ BA + $4.0{\mu}M$ Kn + $0.5{\mu}M$ NAA + 15% coconut water (CW). The shoot multiplication rate was amplified about twofold per culture after the addition of 15% CW to the medium. The rate of shoot multiplication reached maximum at the 5th subculture, and it maintained this rate throughout the 3 subsequent subcultures. The best rooting in vitro was investigated by subculturing the microcuttings in an $MMS_2$ (half strength of both major salts and minor salts and full strength of vitamins) medium containing $1.0{\mu}M$ IBA in the dark for one initial week at $30^{\circ}C$, followed by subculturing them in a plant-growth regulator (PGR)-free medium in the light. The plantlets raised in vitro were successfully established under ex vitro conditions.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1996.06c
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• pp.1045-1054
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• 1996

Tissue culture, or micropropagation , is being used for the vegetative multiplication of several hundred millions of superior plants annually for horticulture and forestry. It is often more expensive than other forms of propagation using cuttings or seeds, because it is labor intensive and more specialized . The aim of automation is to reduce the cost per plantlet by reducing labor input, and finally, to yield profit, as business activity . Labor usually account for 70-80% of th ein vitro and ex vitro cost. This paper aspects of tissue culture automization , such as technical and economical approaches in view of automization.

• Journal of Ginseng Research
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• v.28 no.4
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• pp.211-214
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• 2004

This study was carried out to find out the optimum hardening condition for ginseng plantlets redifferentiated by tissue culture method. While a lot of root hair were observed on the root of seedling grown on the soil, few root hair were observed on the root of plantlet redifferentiated in vitro. On the medium solidified with $0.1{\%}$ phytagel, root hair was not observed and root weight, root width and laternal root development were also very poor. While raising the phytagel concentration on the media, root hair began to increase and root weight, root width and latemal root development were improved. Vascular tissue of plantlet grown on the medium with $0.1{\%}$ phytagel was very poor, but that of plantlet grown on the medium with $0.8{\%}$ phytagel was very good.

• Korean Journal of Plant Tissue Culture
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• v.24 no.6
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• pp.323-327
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• 1997

Addition of growth inhibitors such as ancymidol, ABA, chloromequat, and pachlobutrazol into MS medium had no effect to preventing vitrification in cultures of Rehmania glutinosa. Anatomical investigation revealed that vitrified thick leaf tissue in vitro had larger intercellular space with poor development of sponge and pallisade tissue compared to those of in vitro grown glaucous and field grown plants. In vitro grown glaucous leaf had smaller and round type stomata showing distinguishable guard and subsidiary cell than those of reestablished plantlets into soil whereas abnormal stomata and poor development of epicuticular wax on the surface of leaf was observed in verified plantlet.

• Korean Journal Plant Pathology
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• v.10 no.2
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• pp.140-143
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• 1994

Comparison of susceptibility of asparagus (Asparagus officinalis L.) seedlings and plantlets to different fusarial species was made to determine whether in vitro propagated asparagus plantlets can be used as a substitute for seedlings in histopathological study on the infection processes of Fusarium species to asparagus. Fusarium oxysporum was isolated most frequently (50% of the total) from lesions of root and crown rot of asparagus cultivated in the field followed by F. moniliforme (8.8% of the total) and F. solani (2.9% of the total). Plantlets and seedlings of all asparagus were susceptible to f. moniliforme and F. oxysporum isolates, but those were not susceptible to both avirulent F. oxysporum (AVFO) and F. solani in pathogenicity tests. Overall, there were no differences between seedlings and plantlets in the susceptibility to virulent fusarial infections. In vitro propagated asparagus plantlets, therefore, could be used as a substitute for seedlings in histopathological study on the infection processes of Fuasrium species to asparagus.