• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.248-253
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• 1988

The longer pollen stage grew to flowering stage, the higher anther respiratory rate in vivo became. and it was rapidly increased just before flowering. The anther respiratory rate in vitro showed the first and second peak points after 3-7 days and 9-1l days in culture, respectively, and fastest and highest in Daecheongbyeo with high sporophytic potentiality. It was lower in cold-pretreatment than non-treatment at the early days, but higher from 15 days after culture. The frequency of browning anthers was promoted by cold-pretreatment. The respiratory rate was not different between uncolored and browned anthers at 12 days, but it was higher in browned anthers after 24 days in culture.

• KSBB Journal
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• v.5 no.3
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• pp.269-277
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• 1990

Methylobacillus sp. SK1, an obligate methylotroph, was cultivated in a fed-batch culture using DO as a methanol feeding indicator with a micro computer-aided control system. While 2.07g/l of cell density was obtained after 13 hr in the batch culture (initial methanol concentration: 1.0%(v/v)),45.3g/l of cell density was obtained after 17 hr by feeding methanol and metal ions in the fed-batch culture with oxygen supply. The high-density biomass was obtained in short cultuivation time by fed-batch culture with feedback control, and consequently the biomass productivity was significantly increased. It was mainly due to extension of logarithmic growth period by methanol feeding without methanol inhibition and intensive aeration without DO limitation with microcomputer-aided control system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.425-430
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• 1983

Rice (Oryza sativa L.) anthers collected from different genotypes were cultured to investigate the priority to increase callus production rate among several factors affecting on callus formation. Rice varieties, F$_1$ hybrids and F$_2$ plants differed greatly in their abilities to produce callus from anthers, and it was confirmed that the culturability of rice anther was a heritable characteristic. Cold shock treatment before plating anthers promoted callus formation rate, but combined effect with genotype having high culturability was more significant. The response to sucrose concentration in culture medium in callus induction rate was different between rice genotypes, but combined effect with genotype was not significant. Single supplement of NAA to R$_2$ medium increased callus production rate remarkably only in rice genotype having high culturability. Conclusively selection of genotypes is most important to increase callus initiation frequency from rice anthers.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.138-140
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• 1999

These studies were carried out to investigate the effects of cold pretreatment, dark condition, and Ficoll on the callus formation and organ differentiation in anther culture of carnation for the purpose of settling the techniques of anther culture of 'Rony' carnation. Diameter of flower buds containing anthers with microspores before or after uniuncleated stage was between 4 and 6 mm. A high percentage of callus formation and responding anthers were achieved by low temperature pretreatment at $4^{\circ}C$ for 7 days. Callus formation was promoted under dark condition. Roots were differentiated from calli formed under darkness. Ficoll didn't promote callus formation but promoted differentiation of shoots and roots.

• Journal of Plant Biotechnology
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• v.50
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• pp.19-26
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• 2023

Korean ginseng (Panax ginseng Meyer) is an economically important plant because of it is rich in saponins. It is mainly cultivated in Asia, including Korea and China. Since ginseng requires a long breeding period due to juvenility, homozygote production techniques, such as anther culture, must be urgently established. In the present study, callus induction and embryogenesis through anther culture were observed in P. ginseng. Murashige and Skoog medium was used as the basal medium suitable for callus induction. When the medium was supplemented with 3% sucrose, the callus induction rate was high and the callus size was large. Cold pretreatment did not significantly affect callus induction and embryogenesis. Embryogenesis was the most efficient when the embryo-formation medium was supplemented with 1.0 or 3.0 mg/L 2,4-dichlorophenoxyacetic acid. Cultivar significantly affected anther culture efficiency. Specifically, 'Cheongseon' showed the highest embryo-formation efficiency, whereas no embryogenesis occurred in 'Sunun'. Ploidy assessment revealed the haploid status of the induced calli. Embryos derived from anther culture formed shoots upon transfer to germination medium, although no difference in ploidy was noted between the induced callus and control. Overall, the anther culture conditions established in the present study may contribute to the production of homozygous P. ginseng plants in the future.

• Korean Journal of Plant Tissue Culture
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• v.21 no.1
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• pp.35-39
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• 1994

Is obtain cell lines showing high level of rice cold tolerance, direct in vitro selection through cold stress on primary pollen callus derived from anther culture was carried out Genotypic difference in callus formation and plant regeneration was recognized Rates of albino was increased along the duration of cold stress. Reciprocal effects were not noticed in anther culturability There was no variants related to rice leaf discoloration in pollen derived lines from parental varieties, regardless of days of cold stress. The regeneration and recombination of rice leaf discoloration in 146 pollen-derived lines, 70 pollen-derived lines from cold stress at $0^{\circ}C$ for 10 days, and 830 F$_2$ plants presented normal distribution curves with skewness in tolerance and no significant difference among 3 populations. Direct in vitro selection for rice cold tolerance through cold stress on primary pollen callus derived from anther culture, therefore, was revealed ineffective as a in vitro technology.

• Journal of Life Science
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• v.31 no.4
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• pp.385-388
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• 2021

Anther cultivation for crop breeding is a method of rapid production of homozygosities by greatly reducing the time required for at least six generations to develop new varieties using conventional breeding methods. This technique of producing anther culture provides an opportunity to obtain more green plants from a methodological point of view, and the techniques that save time and effort in anther culture are also important because they increase the efficiency of culture. This study compared the callus induction rate and green plant regeneration rate of a one-step and a two-step culture that differ in their culture media and culture methods. One-step culture allows callus induction and plant regeneration in one medium, whereas two-step culture requires induction and plant regeneration in two different media. In this study, we compared the callus induction and plant regeneration rates of rice anthers as one-step and two-step cultures. The callus formation rate was 13.0% for one-step cultures and 8.6% for two-step cultures, so the rate was 4.4% higher for one-step cultures than for two-step cultures. The plant regeneration rate was 1.0% in one-step cultures and 3.0% in two-step cultures, so the regeneration rate was three times higher for the two-step cultures than for one-step cultures. This suggests that the two-step cultures are more efficient than the one-step cultures for haploid production.

• Journal of Plant Biotechnology
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• v.30 no.4
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• pp.365-368
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• 2003

Variations of agronomic traits were evaluated on the progenies of regenerated rice plants of different callus origin and subculture period. From eighty-eight percent to ninety percents of ovary culture-derived plants (OCP) and anther culture-derived plants (ACP) were not segregated within the lines in major agronomic characters. Compare to ACP and OCP lines, the seed culture derived lines (SCP) showed more segregation (17％) in major agronomic traits among the lines. The most frequent segregating traits were grain fertility (6.1％) in ACP, leaf color (4.2％) in OCP and grain fertility (4.9％) and leaf color (4.9％) in SCP lines. The SCP line showed more variation in culm length, panicle length and heading date than those of OCP and ACP lines. The variation of agronomic traits in SCP lines was tended to increase with prolonged subculture. Culm and panicle length were shorter than those of original cultivar in all three types of tissue culture-derived lines (OCP, ACP and SCP).

• Korean Journal of Plant Tissue Culture
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• v.27 no.6
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• pp.429-434
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• 2000

Isolated protoplasts from ginseng (Panax ginseng C. A. Meyer) callus tissue were cultured in modified MS media supplemented with various concentrations of dimethylsulfoxide (DMSO). The cell wall regeneration rate and cell division efficiency of the protoplasts were increased significantly by 1% DMSO treatment. However, there was no difference in the viability of protoplasts between the DMSO treatment and non-treatment. Transmission electron microscopy revealed that the microtubules were oriented in parallel manner to the plasmalemma after 3 days of culture in medium with 1% DMSO. Further, interconnected cellulose microfibrils were observed on the outer surface of the 3-day-cultured protoplasts by scanning electron microscopy These structures shown by electron microscopy were not observed in protoplasts cultured on DMSO-free media. This studies indicates that DMSO supplemented in culture media seemed to stimulate the cell wall regeneration and cell divisions of protoplasts by forming microtubule organizing centers (MTOC).

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.525-532
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• 2020

A continuous fermentation process was carried out to enhance hyaluronic acid (HA) production using Streptococcus zooepidemicus cells. During the 1st stage continuous operation from 8 h with a dilution rate of 0.029/h (D1), HA was produced in the range of 7.5-10 g/l. During the 2nd stage from 44 h with a dilution rate of 0.036/h (D2), HA production (8.28 g/l) was initially reduced to a small extent due to increase of dilution rate from D1 to D2, and then a new pseudo-steady state was formed within a few hours with a concurrent small variations of HA production. The HA amount produced during the latter part of the 2nd stage was stably maintained in the range of 8.28-9.48 g/l, about 4.7% less amount compared to the 1st stage. Due to 24% increase of dilution rate from D1 to D2, however, maximum volumetric productivity (DP) amounting to 0.341 g/l/h was obtained at 96 h during the 2nd stage. This maximum productivity obtained from the continuous culture turned out only a small increase (3%) as compared to the corresponding batch fermentation. However, it should be noted that, in the case of batch process, one run typically consists of serial stages of growth culture plus one final production culture. This implies that, if the continuous fermentation that practically needs no dead time necessary for the multi-stage growth cultures is run for longer period, the total amount of the accumulated HA would be far greater than the amount obtained from the corresponding batch culture performed for the identical period.