• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.115-120
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• 1989

Universal characteristics of ginseng replanting problems appeared to be decrease in root yields due to root rot and inhibition of root growth. Incitants of ginseng replanting problems have not been clearly elucidated, however, it appeared to be a complex phenomenon with several pathogenic soil microorganisms and environmental changes in the soil due to decomposition of ginseng debris such as rootlets and shoots. Decomposition of ginseng debris may cause direct or indirect damage to the root. The effect of conventional fungicide on the control of the problems has not been recognized. However, it has been suggested that treatment with soil fumigants may solve the problems. Meanwhile paddy-rice and ginseng rotation system appeared to be the best way of solving the problems so far.

• Plant Resources
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• v.7 no.1
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• pp.29-35
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• 2004

Root chicory (Cichorium intybus L. var. sativus) is potential alternative medicinal and sugar crop which accumulates a high amount of linear polyfructan, inulin in its roots. A problem in root production is that over-wintered stock plants often flower. Once the plant becomes reproductive, stem elongation and root growth slows and floral buds arise from every node, rendering the plants useless for propagation. The objectives of this research was to examine the effectiveness of manipulating environmental factors containing photoperiod, temperature and number of leaf states. The experiment was performed in growth chamber to create two photoperiods (8 h, and 16 h) with three temperature regimes (5$^{\circ}C$/3$^{\circ}C$, 1$0^{\circ}C$/8$^{\circ}C$ and 15$^{\circ}C$/13$^{\circ}C$ day/night temperature) for a total of six treatments on three type of true-leaf stage of plant. Data of bolting rate, shoot and root length, shoot and fresh weight was invetigated in each treatments. This is the first report on changes in bolting rate and shoots and roots production during a whole growing season and differences in the effect of cold and photoperiod treatment depending on the true-leaf stage of plant.

• Korean Journal of Medicinal Crop Science
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• v.14 no.1
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• pp.31-35
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• 2006

A protocol for plant regeneration from hairy root of Rehmannia glutinosa transformed by Agrobacterium rhizogenes ATCC15834 has been developed. Transgenic shoots were regenerated from hairy roots within 6 weeks after culture on the SH medium supplemented with 0.5 mg/l BA. Shoots were rooted on plant growth regulator free SH medium successfully. The transformed plants, which were regenerated from hairy roots, had thiner roots with extensive lateral branches, wrinkled leaves, shorter node, and grew faster compared with non-transformed plants. The biomass of the transformed plant was 1.28 g (F.W) per plant, significantly higher than the non-transformed plant (0.54 g F.W). The catalpol content in the transformed plant (0.56%) was also higher than that of the non-transformed plants (0.43%).

• Journal of Microbiology and Biotechnology
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• v.31 no.11
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• pp.1526-1532
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• 2021

Suaeda australis, Phragmites australis, Suaeda maritima, Suaeda glauca Bunge, and Limonium tetragonum in the Seocheon salt marsh on the west coast of the Korean Penincula were sampled in order to identify the endophytes inhabiting the roots. A total of 128 endophytic fungal isolates belonging to 31 different genera were identified using the fungal internal transcribed spacer (ITS) regions and the 5.8S ribosomal RNA gene. Fusarium, Paraconiothyrium and Alternaria were the most commonly isolated genera in the plant root samples. Various diversity indicators were used to assess the diversity of the isolated fungi. Pure cultures containing each of the 128 endophytic fungi, respectively, were tested for the plant growth-promoting abilities of the fungus on Waito-C rice germinals. The culture filtrate of the isolate Lt-1-3-3 significantly increased the growth of shoots compared to the shoots treated with the control. Lt-1-3-3 culture filtrate was analyzed and showed the presence of gibberellins (GA₁ 2.487 ng/ml, GA₃ 2.592 ng/ml, GA₉ 3.998, and GA₂₄ 6.191 ng/ml). The culture filtrate from the Lt-1-3-3 fungal isolate produced greater amounts of GA₉ and GA₂₄ than the wild-type Gibberella fujikuroi, a fungus known to produce large amounts of gibberellins. By the molecular analysis, fungal isolate Lt-1-3-3 was identified as Gibberella intermedia, with 100% similarity.

• Journal of Ginseng Research
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• v.6 no.1
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• pp.38-45
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• 1982

To determine the optimum light intensity for growth of ginseng plants, change of temperature, moisture content in son, occurrence alternaria blight, defoliation rate, chlorophyll contents, and growth of shoots and roots were investigated under different light intensity such as 5%, 10%, 20% and 30% light transmittance rare(L.T.R.). The results obtained were as follows. 1. Maximum temperature under the shading was increased as the increase of light intensity, whereas soil moisture content decreased 2. As the increase of light intensity, stem and Peduncle length, leaf area, and chlorophyll contents decreased significantly but length and width of the leaf was not significant, while stem diameter, special leaf weight and chlorophyll a/chl. b ratio increased 3. Stem color was shown dark purp!e as the increase of light intensity. 4. Photosynthesis during the day was highest at 9 A.M. and decreased as time passed in all plots. The means of photouynthesis during the day showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for highest photosxthesis was 18.4% L.T.R. by theoritical equation. 5. It was showed a tendency that alternaria leaf blight of ginseng plants was increased as the increase of light intensity. 6. Defoliation rate of ginseng plants was increased as the increase of light intensity, especially all plants were defoliated by late June without shading. 7. Yield percentage of the rear line was increased as the increase of light intensity. Root weight per plant showed in the order of 20%, 10%, 30%, 5% L.T.R., and optimum light intensity for the best yield was 18.5% L.T.R. by theeritical equation.

• Journal of Plant Biotechnology
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• v.45 no.2
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• pp.140-145
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• 2018

Inducing genetic and morphological variation through conventional method is very difficult. Therefore, mutation induction through in vitro technology brings numerous advantages over the conventional breeding. Thus, the individual shoots (1 ~ 2 cm) were irradiated with gamma rays (10 ~ 70 Gy). The result revealed that the explants treated with higher doses (40, 50, 60, and 70 Gy) showed deleterious effects of ionizing radiation. The highest survival rate among ${\gamma}$ treated explants recorded was 71% in 10 Gy treatments while the lowest survivality was 15% in 70 Gy. Lethal dose 50% ($LD_{50}$) dose was found to be 33 Gy. In the in vitro condition, rooting reponse showed that increase in gamma irradiation dose resulted in the inhibition of root growth. Meanwhile, non-treated explants had the best rooting ability with the maximum number of root per explant (20) within a short period of time (6 days), with the highest root length of (15.1 cm). The longer period in rooting (12 days) and lowest number of root per explant (8) with shortest root length (10.1 cm) were recorded at 30 Gy treatment. The highest shoot length (13.6 cm) was observed at control treatment and the shortest shoot length (10.4 cm) was observed at 30 Gy. In the nursery, lowest leaf number (5) was observed at 30 Gy compared with other treatments. The highest chlorophyll content (49.8) was recorded at 10 Gy treated seedling. Irradiated explants with 10 Gy found to be superior over the control treatment and had positive effects in main growth parameters such as chlorophyll content.

• Plant Resources
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• v.6 no.3
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• pp.233-241
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• 2003

The shoot tip and young leaf of Rhodiola sachalinensis were cultured to invest the plant growth regulator condition for callus induction, shoot and root regeneration. When the shoot tip was sterilized in 2.0% of NaOCl for 20min., the contamination rate was the lowest. And the survival rate of the culture material was good in carbenicillin 500mg/L treatment group. Callus was obtained from shoot tip and young leaf segments. NAA 0.1-1.0mg/L and 2,4-D 0.1-0.5mg/L alone treatment were shown to have a good response on callus induction from shoot tip culture. In the case of young leaf culture, NAA and 2,4-D 0.1-0.5mg/L alone treatment were good in callus induction. In culturing shoot tip NAA 0.5mg/L and BA 0.5mg/L, NAA1.0mg/L and BA 0.lmg/L combination treatment was good in shoot regeneration. The regenerated shoots were rooted on MS medium supplemented with NAA and BA combination treatment. Especially, NAA 1.0mg/L and BA 0.1mg/L combination treatment was effective for root regeneration.

• Journal of Plant Biotechnology
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• v.37 no.3
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• pp.337-342
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• 2010

To establish the optimum conditions of in vitro plant regeneration, the leaf, rhizome, and root explants of Belamcanda chinensis were cultured on the MS medium supplemented with different concentration of 2,4-D and BA. The callus induction was more effective in the root explants than the leaf and rhizome explants, and was the best on MS medium containing 3.0 mg/L 2,4-D or 1.0 mg/L 2,4-D and 3.0 mg/L BA. The highest numbers of shoots were regenerated when callus were cultured on MS medium containing 3.0 mg/L 2,4-D for 4 weeks. However, the multiple shoots were induced on MS medium supplemented with the combination of 2,4-D and BA. The normal root formation from shoot was effective on the MS medium lacking any plant growth regulators. For acclimatization, the regenerated plantlets were cultured on MS medium without sucrose and plant growth regulators for 2 weeks, and then transferred to the pot.

• Korean Journal of Plant Resources
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• v.26 no.2
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• pp.303-309
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• 2013

This study was performed to clarify the effect of medium compositions and plant growth regulators on the shoot, root formation and growth of 'Jarang' grape for mass propagation of virus-free plant. The formation and growth of shoot were considerably favorable in half-concentration of MS medium. However, the formation of adventitious root per explants (avg. 2.1) was effective in higher concentration (two times) of MS medium. For sucrose concentration, 1% for the shoot formation, 3% for the adventitious root formation and 1% for the growth were observed as yield significant results. With the addition of 0.05% of activated carbon, the shoot growth was improved, and it was effective for the adventitious root formation and growth as well. A pH of 6.8 in the medium was the most suitable for mass propagation; the results showed significant enhancement in the number of nodes and the length of the shoot, 3.9 and 1.3 cm, respectively. The shoot growth was the most vigorous in BA 1.0 mg/L due to the impact of the growth regulator on the mass propagation in it. Consequently, 16.9 shoots per explant were formed in NAA 1.0 mg/L so good results were obtained.

• Horticultural Science & Technology
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• v.33 no.4
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• pp.585-590
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• 2015

This study was conducted to improve the acclimatization rate of in vitro strawberry plantlets through bioreactor culture using the growth retardant flurprimidol. Different concentrations [0 (Control), 0.1, 0.5, 1.0, and $2.0mg{\cdot}L^{-1}$] of flurprimidol were added during bioreactor culture. After six weeks of treatments, various growth characteristics were investigated and in vitro plantlets were acclimated in the greenhouse. The growth rate of treated plantlets was much lower than that of control, and as the treatment concentration increased, the growth rate was much decreased. Shoots of plantlets treated with flurprimidol were shorter (2.2-3.7 cm) than those of control (7.9 cm). The number of roots per treated plant was around 11.6-34.2, compared with 51.8 in the control. Root length was also lower (0.88-3.08 cm) than control (4.36 cm). However, the number of new shoots and leaves increased in all treatments except for $2.0mg{\cdot}L^{-1}$ concentration. The root was partially decayed in $1.0mg{\cdot}L^{-1}$ concentration and was completely decayed in $2.0mg{\cdot}L^{-1}$. The survival rate in $0.1mg{\cdot}L^{-1}$ and $0.5mg{\cdot}L^{-1}$ concentrations was 100% and 23.3% respectively. After four weeks of acclimatization, the plantlets restarted growth, and growth characteristics of shoots and roots recovered to the levels of control, except for fresh weight. Based on our results, a concentration of $0.1mg{\cdot}L^{-1}$ flurprimidol is appropriate for improvement of acclimatization rate of in vitro strawberry plantlets in bioreactor culture.