• Korean Journal of Medicinal Crop Science
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• v.17 no.4
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• pp.238-242
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• 2009

Somatic embryos on growth regulator-free medium can be produced directly from cotyledon explants of Panax ginseng C. A. Meyer. When the embryo developmental stage was torpedo and cotyledon, the germination rate of embryos was quite high on MS medium supplemented with gibberellic acid ($GA_3$). However, the percentage of plantlet formation at the cotyledon stage was higher than that at the torpedo stage. This result demonstrates that the embryo at the cotyledon stage was the most appropriate for increasing germination by $GA_3$. Embryos cultured on medium including four levels of $GA_3$ concentrations (3, 5, 10, or 20 mg/$\ell$) showed all quite high germination rates (87-91%). When the well-developed embryos were continuously cultured on media including high concentrations of $GA_3$ from 10 to 20 mg/$\ell$, the percentage of formation of normal plantlets was lower than that seen under low concentrations from 3 to 5 mg/$\ell$. This treatment of high concentrations resulted in shoots with abnormal shape. The optimal $GA_3$ treatment provides a basis for the efficient method obtaining healthy plantlets derived from ginseng somatic embryos.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.522-527
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• 2010

Gibberellic acid ($CA_3$) is used in many industries and constitutes the primary gibberellins produced by fungi and bacteria. However, there is no information on $CA_3$ production by Methylobacterium oryzae CBMB20, a novel plant growth promoting bacterium. We investigated the favorable carbon (C) and nitrogen (N) sources and ratios and cultural conditions, such as incubation temperature, pH of the culture medium, and incubation period for the maximum production of $CA_3$ by Methylobacterium oryzae CBMB20. Maximum $CA_3$ production was observed in ammonium mineral salt (AMS) broth supplemented with Na-succinate and $NH_4Cl$ as C and N sources, respectively. The maximum $CA_3$ production was found at the C/N ratio of 5:0.4 g $L^{-1}$. The highest $CA_3$ production was obtained when the bacterial culture was incubated at $30^{\circ}C$ for 96 h at pH 7.

• Microbiology and Biotechnology Letters
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• v.11 no.3
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• pp.217-222
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• 1983

By the treatment of Gibberella fujkuroi I-892 with mutagen such as UV light and N-methyl-N'-nitro-N-nitrosoguanidine, a mutant G. fujkuroi G-471 was selected as the highest producer of gibberellic acid among 800 mutant strains. It showed 30% increase of production yield compared with that of the parent strain. At optimum medium composition (saccharose 1.0%, ammonium tartarate 50mM, malt extract 1.0% KH$_2$PO$_4$ 0.5%, MgSO$_4$0.5%, FeSO$_4$0.0002%, trace element sol.0.002% (v/v), the yield of submerged culture increased by 30% after 7 days culture at 24$^{\circ}C$ (253mg/$\ell$). In submerged culture, the initial pH showed much effects on the increase of gibberellic acid production. The highest yield of the production was attained with pH adjustment to 4.0 at the initial stage of fermention.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.39-45
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• 1984

The present researches were carried out to investigate the effects of gibberellic acid on the appearance of isozyme patterns of esterase, phosphatase, amylase and peroxidase, also to investigate if there were any differences of the isozyme patterns among root, shoot and seeds of rice plants. It was noticed that the isozyme patterns of the above tested enzymes were differ among the organs, root, shoot and seed. The GA treated plants showed difference of esterase patterns in root from Akibare and the difference in shoot and root from Yushin, phosphatase patterns in root from Akibare. However, the GA did not affect isozyme patterns of amylase or peroxidase. The seed should be the suitable organ to study isozyme patterns for genetics or variety characterization of rice plant.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.59-63
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• 2021

To study for germination rate of apple artificial seeds encapsulated with 2% alginic acids, the rates of germination for artificial seeds of various embryos with partial elimination of cotyledon measured by adding 80 mg/L gibberellic acid or/and nutritional media. The germination rate of artificial seeds produced embryo with 3/4 cotyledon (3/4 CE), embryo with 1/2 cotyledon (1/2 CE), embryo with 1/4 cotyledon (1/4 CE), and embryo without cotyledon (NCE) were gradually decreased with compare to normal embryo, but it's considerably recovered on the alginic acid containing MS solution or/and 80 mg/L GA3. In special, the low frequency (55.81%) of germination for artificial seeds of 1/2 cotyledon embryo with alginic acid was increased by treatment with combination of alginic acid, 3% sucrose, and 80 mg/L gibberellic acid (98.74%). In case of embryo without cotyledon, the low frequency of embryo without cotyledon (24.44%) in alginic acid almost recovered to 82.45% in alginic acid with MS solution and 80 mg/L gibberellic acid. The results shown that the germination of embryo was decreased by the removal of cotyledon, and demonstrated that the low rate of germination could be considerably increased by adding GA3 (80 mg/L) or/and nutrition.

• Journal of Bio-Environment Control
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• v.24 no.1
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• pp.27-33
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• 2015

High temperature stress in summer season at plastic house is a limiting factor for tomato fruit set and yield. This study was performed to assess the effects of gibberellic acid ($GA_3$) and 2,4-Dichlophenoxy acetic acid (2,4-D) spray on fruit set, yield, and quality of tomato cv. 'Adoration'(Enza Zaden Co., Ltd.) under the plastic house in Hwacheon, 2011. Four concentrations (0-, 5-, 10- and $15mg{\cdot}L^{-1}$) of $GA_3$, and three concentrations (0-, 5- and $10mg{\cdot}L^{-1}$) 2,4-D were sprayed in early flowering of tomato in the plastic house, and fruit set, yield and quality characters were observed. The results showed that spray of $10mg{\cdot}L^{-1}$ $GA_3$ significantly increased the fruit set by 14.2% than unsprayed. The spray of $GA_3$ significantly increased the marketable fruit number, fruit weight, and yield. The spray of 2,4-D on blossoms significantly affected the fruit set percentage, fruit weight, marketable fruit weight and yield, and the highest fruit set observed as 62.5% in combined spray of $GA_3$ and 2,4-D at each $5mg{\cdot}L^{-1}$. Fruit size and total soluble solids significantly varied with the concentrations of $GA_3$ sprayed. The result indicates that the spray of $10mg{\cdot}L^{-1}$ $GA_3$ and $5mg{\cdot}L^{-1}$ 2,4-D can be more economic and effective to increase the fruit set, and yield in tomato under high temperature condition in plastic house.

• Journal of Plant Biotechnology
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• v.47 no.1
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• pp.53-65
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• 2020

Here, we describe an efficient and rapid protocol for the micropropagation of Thymus pallidus Cosson ex Batt., a very rare medicinal and aromatic plant in Morocco. After seed germination, we tested the effect of different macronutrients, cytokinins alone or in combination with gibberellic acid (GA₃) or auxins, on T. pallidus plantlet growth. We found that Margara macronutrients (N₃₀K) had the best effect on the in vitro development of the plantlets. The addition of 0.93 μM/L 1,3-diphenylurea (DPU), 0.46 μM/L adenine (Ad), and 0.46 and 0.93 μM/L kinetin (Kin) resulted in the best shoot multiplication and elongation. In addition, the combination of 0.46 μM/L Kin, DPU, or Ad with gibberellic acid, in particular, 0.46 μM/L Ad + 0.58 μM/L GA₃ and 0.46 μM/L Kin + 1.15 μM/L GA₃, led to better bud and shoot multiplication. Moreover, the integration of the combinations of 0.46 μM/L Kin and auxins, namely 0.46 μM/L Kin + 2.85 μM/L indole-3-acetic acid (IAA), 0.46 μM/L Kin + 2.85 or 5.71 μM/L indole-3-butyric acid (IBA), and 0.46 μM/L Kin + 0.3 or 0.57 μM/L 1-naphthaleneacetic acid (NAA), in the culture medium led to better root development and optimized aerial growth. Finally, the in vitro plants from the medium containing N₃₀K + 0.46 μM/L Kin + 2.85 μM/L IAA were successfully acclimatized; these plants served as a source for repeating in vitro culture.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2003.10a
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• pp.165-165
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• 2003

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.165-166
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• 2009

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.10a
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• pp.227-227
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• 2021