• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.184-190
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• 1993

This study was carried out to investigate the appropriate medium and constitutionof growth regulators for somatic embryogenesis for development of rapid mass propagation system via somatic embrygenesis in Rehmennia glutinosa. Embryogenic callus formation from leaf explant was more effective when 4mg / l BA with 0.5mg / l NAA than that of treated with only auxins or cytokinins. LS medium was suitable for embryogenic callus formation. LS medium with 4mg / l BA with 0.5mg / l NAA was effective for the maintenance and proliferation of embryogenic callus. In suspension culture, addition of 1mg / l BA to LS medium was proper for somatic embryogenesis. The highest rate of shoot developement form cotyledon stage embryo was obtained in 1/2 LS medium and plantlet survived by 75% after transplanted to the soil. after 4 weeks.

• The Korean Journal of Mycology
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• v.26 no.1 s.84
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• pp.91-96
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• 1998

Optimal conditions for the preservation of mushroom cultures in sterile distilled water were investigated. Mycelial disks from 12 mushroom cultures were preserved at room temperature, $5^{\circ}C,\;-20^{\circ}C$ and $-75^{\circ}C$ using sterile water and 6 cryoprotectants for 12 months. The maximal viability of mycelial disks was observed at room temperature and $5^{\circ}C$ with the value of 91.7%. At $-75^{\circ}C$, the viability was highest in polyethylene glycol (PEG) and lowest in 10% dimethyl sulfoxide (DMSO). The average mycelial growth was highest for disks preserved at $-75^{\circ}C$ in PEG. PEG was the most suitable for the preservation at $-75^{\circ}C$, although this chemical has rarely been used as a cryoprotectant in fungal culture preservation. The laccase isozyme patterns of the preserved isolate of H. ferrugineum were not changed during preservation at $5^{\circ}C$ in sterile distilled water as compared to that of slant culture.

• Microbiology and Biotechnology Letters
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• v.42 no.2
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• pp.99-105
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• 2014

A Bacillus strain capable of hydrolyzing locust bean gum was isolated as a producer of extracellular mannanase by way of an enrichment culture in an acidic medium from homemade soybean pastes. The isolate YB-1401 showed a biochemical identity of 61.1% with Brevibacillus laterosporus, while the nucleotide sequence of its 16S rDNA had the highest similarity with that of Bacillus amyloliquefaciens. The mannanase productivity of the Bacillus sp. YB-1401 was drastically increased by mannans. Particularly, maximum mannanase productivity was reached at approximately 265 U/ml in LB medium supplemented with konjac glucomannan (4.0%). The mannanase was the most active at $55^{\circ}C$ and pH 5.5. Mannanase activity was completely maintained after pre-incubation at pH 3.5 to 11.0 for 1 h. The predominant products resulting from the mannanase hydrolysis were mannobiose and mannotriose for LBG, guar gum or mannooligosaccharides. A small amount of mannose was also detected in the hydrolyzates.

• Applied Biological Chemistry
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• v.39 no.5
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• pp.389-397
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• 1996

The volatile concentrate obtained from the edible Korean dureup plant (Aralia elata Seem.) by a distillation-extraction system was separated into hydrocarbon and oxygen-containing fractions, and the latter was further separated into nine subfractions by silica gel column chromatography. Gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS) were utilized to identify 167 volatile compounds in the fractions. The volatile compounds included 72 hydrocarbons, 31 alcohols, 23 aldehydes, 16 esters, 10 acids, 6 ketons, 3 furans, 2 phenols, 1 indole, 1 oxide, 1 sulfide, and 1 lactone. ${\beta}-Caryopyllene$, a sesquiterpene hydrocarbon, was the most abundant volatile compound identified in Korean dureup (19.53%). Dureup oil was found to possess a woody or herbaceous aroma following sensory evaluation of each fraction and individual volatile component using a GC-sniff apparatus.

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.103-111
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• 2011

Monochoria vaginalis var. plantaginea (Pontederiaceae) is one of the most problematic weed in the rice field in Korea. Tanysphyrus (Tanysphyroides) major was selected as a potential biological control agent for M. vaginalis. Continuous rearing of T. (T.) major was carried out from 2006 to 2007, and its morphological characteristics and ecological characteristics were investigated. This species has a single generation per year, over-wintering as an adult stage. The emergence of adults starts in later June and last until September. These observations indicate that T. (T.) major takes $22{\pm}0.7$ days to develop from egg to adulthood. Host specificity test showed that finally selected this species was suitable candidates for the biological control of M. vaginalis var. plantaginea since it showed negative host specificity against major 60 test crops.

• Parasites, Hosts and Diseases
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• v.36 no.1
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• pp.47-54
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• 1998

Small subunit ribosomal RNA (SSU rRNA) gene nucleotide sequences of bovine ReiLerin isolates from Korea (KLS and KCB) and japan (JHS) were determined. The genes from each isolate were amplified by the polymerase chain reaction and the approxi- mately 1.8 kb product cloned and sequenced by a modified dideoxynucleotide method. Overlapping gene segments produced with a series of primers were sequenced, resoRting in a complete DNA sequence for both forward and reverse strands of the SSU rRNA genes of each isolate. SSU rRNA gene sequences (termed Type A) were identical among the bovine ReiLeri,n isolates from Korea and the isolate from Japan. A GenBank data library homolo- gy search showed the sequence to be the same as that listed as leiLeyia buKeLi isolated from cattle in Marula, Kenya.

• Korean Journal of Plant Tissue Culture
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• v.25 no.2
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• pp.125-129
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• 1998

Cucumber (Cucumis sativus L.) plants were regenerated through organogenesis and somatic embryogenesis in cotyledon and hypocotyl cultures. The shoots were efficiently formed on the basal region of cotyledons cultured on MS medium containing 1.0㎎/L zeatin and 0.1㎎/L IAA in all cultivars used. Embryogenic calli were formed on hypocotyl segments cultured on MS medium containing 1.0㎎/L 2,4-D in cv. group 'Nakhab' and maintained by consecutive subculture on the same medium every 2-3 weeks without loss of embryogenic ability. Upon transfer to MS basal medium, high frequency somatic embryogenesis was achieved easily from embryogenic callus. Regenerated plantlets through organogenesis and somatic embryogenesis were transplanted to pots and gradually acclimatized to greenhouse condition where they subsequently produced fruits.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.201-206
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• 1998

To develop the fruits of cucumber (Cucumis sativus L.) producing high yields of superoxide dismutase (SOD), the MnSOD cDNA from pea (Pisum sativum) under the control of the cauliflower mosaic virus 35S promoter was introduced into cucumber using Agrobacterium tumefaciens (strain LBA 4404)-mediated transformation. The kanamycin-resistant shoots were selected on the selection medium containing MS basal salt, 1.0 mg/L zeatin, 0.1 mg/L IAA, 300 mg/L claforan, and 100 mg/L kanamycin. After 6 weeks of culture on the selection medium, the shoots were transferred to MS medium containing 0.2 mg/L NAA to induce roots. PCR analysis using the primers for neomycin phosphotransferase (NPTII) gene revealed that three plantlets were transformed. The fruits of one transgenic plant had approximately 3.2-fold higher SOD activity than those of non-transgenic plants. MnSOD isoenzyme band was strongly detected on native gel in fruits of transgenic plants.

• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.231-236
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• 1998

Carrot cotyledon explants cultured on MS medium with 1 mg/L 2,4-D were transferred to a hormone-free solid medium overlaid with filter paper in order to elucidate the effect of simple physical treatment on the development and germination of somatic embryos. Transfer of the explants cultured for one week on MS basal medium overlaid with 3 sheets of filter paper on to MS basal medium increased somatic embryo production 2-39 times over the one week culture on medium without filter paper overlay. Maturation and germination of somatic embryos was more prominent on medium overlaid with filter paper than on medium without filter paper. The explants cultured for one week on filter paper overlay added with liquid medium showed prominent decrease in somatic embryo formation compared to filter paper overlay only. It is suggested that the filter paper overlay affected the moisture environment of the somatic embryos developing on it.

• Korean Journal of Plant Tissue Culture
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• v.27 no.3
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• pp.191-195
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• 2000

Adventitious shoots were induced from cotyledon and hypocotyl explants of apple hybrid seedlings (P.16$\times$ Malus prunifolia) on MS medium supplement with 2,4-D and various cytokinine (Kn. BA, TDZ) The shoot regeneration from the cotyledon culture was the highest on MS medium supplemented with 1.0 mg/L NAA and 2.0 mg/L BA. Whereas in case of hypocotyl culture, it was the highest on MS medium supplemented with 0.5 mg/L NAA and 0.5 mg/L BA. However, in the MS medium without BA there was no shoot regeneration. Hypocotyl culture seemed to be more effective than cotyledon culture in shoot regeneration. Specially, the top position of the hypocotyl found to be the best explant for shoot induction among the other segments of hypocotyls. Regenerated shoots were rooted on half-stength MS medium with 1.0 mg/L NAA. Above results suggest that Apple hybrid (P.16 $\times$ Malus prunifolia) can be multiplied via cotyledon or hypocotyl culture systems.