• International Journal of Industrial Entomology and Biomaterials
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• v.33 no.2
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• pp.41-49
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• 2016

We bred a mulberry cultivar named Shimgang, through local adaptability test, which is under registration as a new cultivar for fruit production. Local adaptability test had been carried out at four local places(Suwon, Chuncheon, Buan and Jinju) for five years from 2011. This variety 'Shimgang' belongs to Morus Microphylla Buckl. selected from seedlings imported from USA. Shimgang was resistant to popcorn disease and high yielding variety in fruit productivity by 111% compared to control cultivar 'Shimheung(Morus alba L.)' for three years. Although fruits of 'Shimgang' was smaller in size and lower in sugar content of mulberry fruits, it showed stronger resistance than that of 'Shimheung'. It is adaptable to every where except the places where cold and late frost damage happen frequently.

• Journal of Life Science
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• v.20 no.12
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• pp.1792-1800
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• 2010

In this study, we isolated five macrolactin compounds from a fermentation broth of Bacillus polyfermenticus KJS-2. The macrolactin compounds were structurally identified as macrolactin A (MA), 7-O-malonyl macrolactin A (MMA), 7-O-succinyl macrolactin A (SMA), macrolactin E (ME) and macrolactin F (MF) via a variety of NMR techniques, COZY, DEPT, HMQC and HMBC, and mass and specific rotation assays. The three macrolactin compounds, MA, MMA and SMA, profoundly inhibited the growth of both vancomycin-resistant Enterococci (VREs) and methicillin-resistant Staphylococcus aureus (MRSA), the inhibition of which were estimated via a disc agar diffusion bioassay. MA, MMA, and SMA exhibited antibacterial activities superior to those of vancomycin and teicoplanin.

• Journal of Microbiology and Biotechnology
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• v.18 no.9
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• pp.1584-1589
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• 2008

Although resistance of Helicobacter pylori to clarithromycin is a major cause of failure of eradication therapies, little information is available regarding gene mutations of clarithromycin-resistant primary and secondary H. pylori isolates in Korea. In the present study, we examined gene mutations of H. pylori 238 rRNA responsible for resistance to clarithromycin. DNA sequences of the 238 rRNA gene in 21 primary clarithromycin-resistant and 64 secondary clarithromycin-resistant strains were determined by PCR amplification and nucleotide sequence analyses. Two mutations of the 238 rRNA gene, A2143G and T2182C, were observed in primary clarithromycin-resistant isolates. In secondary isolates, dual mutation of A2143G+T2182C was frequently observed. In addition, A2143G+T2182C+ T2190C, A2143G+T2182C+C2195T, and A2143G+T2182C+A2223G were observed in secondary isolates. Furthermore, macrolide binding was tested on purified ribosomes isolated from T2182C or A2143C mutant strains with $[^{14}C]$erythromycin. Erythromycin binding increased in a dose-dependent manner for the susceptible strain but not for the mutant strains. These results indicate that secondary isolates show a greater variety of 238 rRNA gene mutation types than primary isolates, and triple mutations of secondary isolates are associated with A2143G+T2182C in H. pylori isolated from Korean patients.

• Korean Journal of Veterinary Service
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• v.29 no.3
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• pp.277-285
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• 2006

Plasmids are covalently closed circular molecules of DNA that are stably inherited and replicate somewhat independently of the bacterial chromosome. Genes carried on plasmids can mediate a wide variety of important functions, including antibiotics (R plasmids) and heavy metals resistance, toxins production, cell penetration, iron chelation, complement resistance, and metabolic characteristics such as sucrose and lactose fermentation. Fifty strains of lactobacilli were isolated from 26 staters and 29 fermented milk products. They were classified 27 strains as Lactobacillus paracasei subsp paracasei, 11 stains as Lactococcus lactis subsp cremoris, 6 strains as L delbrueckii subsp lactis, 4 strains as L acidophius, and 2 strains as L delbrueckii subsp bulgaricus. All of these strains were examined for drug resistance and transferability of R plasmids. All of the isolates were sensitive to Am, C, CF, E, NB, P, T, and Te. But resistant to SXT 94% (47 strains), K 66% (33 strains), S 56% (28 strains), ENR 50% (25 strains), NOR 38% (19 strains) CIP 38% (19 strains), GM 16% (8 strains), and N 14% (7 strains), in order. And 32 different resistant patterns were found. The most frequently encountered patterns were CIP-ENR-K-NOR-S-SXT (5 strains). In vitro R plasmids transfer experiment, 57 antibiotic resistant strains which were not transfer to the recipient 2 Escherichia coli strains by conjugation, These results indicate that Lactobacillus in internal trade market' stater recognize R factor but transmissible R plasmid is not existed.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.7
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• pp.970-977
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• 2006

Forage oat (Avena sativa L.) is grown extensively in a double-cropping system on dairy farms. Four oat varieties ('Swan', 'Targa', 'Foothill', and 'Nugene') were evaluated for forage production and forage quality during two growing seasons (spring and autumn) at two locations (central and southern region) in South Korea. The heading stage of four oat varieties was observed during spring, but the autumn season did not produce heading until harvest time except for the 'Swan' variety (early-maturing variety). The heading stage of 'Swan' in both locations was earlier compared to other varieties. The four varieties were resistant to both foliar disease and insects. Lodging resistance was higher during autumn except in 2002 at the central region, and late-maturing varieties ('Foothill' and 'Nugene') have lower lodging resistance. Dry matter (DM) content was significantly different between varieties (p<0.001). Comparing different varieties, 'Swan', an early-maturing variety, was highest in DM content. In DM, total digestible nutrients (TDN) and crude protein (CP) yield, the yield of oat varieties in the southern region was higher than in the central region, and forage yield of the oat varieties in the spring season was higher than during the autumn season. The DM and TDN yield showed significant differences between oat varieties. The CP content of oats grown in the central region (Cheonan) was lower than oats grown in the southern region (Daegu), and the spring season produced oats with lower CP compared to the autumn season. Among the four oat varieties, the CP content of late-maturing varieties was higher than the Swan variety (early-maturing variety). The acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents were higher for the varieties grown in Cheonan and during the spring season. The ADF and NDF contents of late-maturing varieties were lower than the early-maturing variety. TDN and relative feed value (RFV) were higher for the varieties grown in Daegu and during the autumn season. Late-maturing variety had higher TDN and RFV than early-maturing variety. Our study showed differences in forage production and forage quality of oats grown in different locations, seasons and varieties. Forage quality as well as forage production was better in the southern region than in the central region. Forage quality was better during autumn, but forage production was better during spring. Late-maturing variety had better forage quality than the early-maturing variety. Therefore, late-maturing varieties are more suitable for use in the southern region.

• Journal of environmental and Sanitary engineering
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• v.23 no.2
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• pp.71-79
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• 2008

We examined 165 unchlorinated natural drinking water samples for the presence of E. coli group resistant to antimicrobial agent and chlorine in nothern Gyeongbuk area in 2007. Among 165 water samples, 21 samples(12.7%) were positive to total coliforms and Six genus, 16 strains of E. coli groups isolated from 16 samples showed resistance against more than one antimicrobial agent such as Ampicillin, Tetracycline and Chloroamphenicol. Among 16 strains, 14 strains resistant to Ampicillin, 9 strains resistant to Tetracycline and one strain resistant to Chloroampenicol. but all 16 strains did not contain any integron gene cassettes, which contribute to the spread of antimicrobial resistance alleles by lateral gene transfer of gene cassettes in a variety of enteric bacteria. The minimal inhibitory concentration(MIC) of 14 strains which showed resistant to Ampicillin was between $12{\mu}g/m{\ell}$ and $32{\mu}g/m{\ell}$, Nine strains resistant to Tetracycline showed between $32{\mu}g/m{\ell}$ and $128{\mu}g/m{\ell}$ and one strain resistant to Chloroampenicol showed $128{\mu}g/m{\ell}$. The chlorine sensitivity of 16 strains isolated from unchlorinated natural water sample did not show any difference among strains by the concentration of initial free chlorine and elapsed time after chlorine treatment. All 16 strains were killed after 1hr. exposure at $0.2mg/m{\ell}$ of free chlorine per liter or 30minutes exposure at $0.4mg/m{\ell}$ of free chlorine per liter.

• Journal of Plant Biotechnology
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• v.5 no.3
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• pp.173-179
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• 2003

The combination of a radiation technique with an in vitro culture system was appiled to develop submergence tolerant rice. The 3,000 $M_3$ lines with an average 80 percent of fertile grain were utilized for the selection of submergence tolerance. Salt tolerant lines were selected based on high plant height, root length and root number after submergence in plastic pots. Of the lines tested, the tolerant line (403-6) showed a dramatic difference in morphological traits under submergence compared to its original variety (Dongjinbyeo). It was suggested that genetic variations between the original variety and $M_3$-403-6 did exist. The levels of $\alpha$-amylase and alcohol dehydrogenase activities were significantly increased in the mutant line compared to its original variety. The mutant with greater tolerance showed less electrolyte leakage indicating a greater membrane integrity and better survival. Also, this line was much more resistant to a salt stress of $1.25\%$ than the original variety. The proline level of the line was significantly (p<0.01> higher than that of the original variety. The relationships between the inhibition of growth caused by stress and the physiological changes in the plant cell were discussed.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.392-396
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• 2003

This study was carried out to determine plant growth and bolting characteristics of Angelica gigas. Three varieties and/or lines Manchu bolting resistant variety, AGJ90-1 medium type line, and bolting Jinbu local were used for field trial in Suwon. FIve different transplanting times were applied on March 25, April 5, April 15, April 25, and May 5th. Survival rate was decreased by the delayed transplantation and it affected after April 25th respectively. Plant growth by the early transplantation showed the best growth during the beginning stage and recognized signifiquence but not by the late transplantation. Bolting rate revealed severe different by the variety and line, it ranged from $10{\sim}8.1%$ of Manchu, $5.9{\sim}20.3%$ of AGJ90-1, and $58.5{\sim}74.6%$ of Jinbu local clearly. By the treatment of transplantation time bolting rate was different, early plantation showed high bolting rate compare to the late plantation from the all of tested variety and lines. Bolting response according to the transplanting time, bolting resistant variety showed insensibility and boling line showed sensitive response. In Manchu root yield was best when planted on April 5th as 389 kg /10a, in case of AGJ90-1 was determined 377 kg/10a when planted on April 15th, and Jinbu local root yield was showed 133 kg/10a planted on April 25.

• Korean Journal of Breeding Science
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• v.40 no.1
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• pp.58-62
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• 2008

A new vegetable peanut cultivar "Charmwon" (Arachis hypogaea ssp. fastigiata.L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang 2006. It was developed from the cross between the disease resistant cultivar "HYQ(CG)S-10" and the high-yielding cultivar "Sinkwang". "Charmwon" which has been classified as Shinpung plant type is less branch number with early flowering and ellipse-shaped large kernel. Each pod which showed very shallow constriction had two grains with red testa and 100 seed weight was 90g in the regional yield trials (RYT). This variety also showed higher free sugar and protein contents in seed quality, and had more resistant to early and late leaf spot diseases compared with check one. In the regional yield trials "Charmwon" was out-yielded than check variety by 18% with 8.93 ton/ha for fresh pod and by 4% with 3.95 ton/ha for grain.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.529-533
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• 2018

Hyowon6, a mid-late maturing, good eating quality rice variety with multi-resistance, was developed by the rice breeding team of Pusan National University in 2013. This variety was derived from a cross between Hwayeong (as a multi-resistant parent) and Koshihikari (as a good eating quality parent). Selection by the pedigree breeding method was carried out until the $F_8$ generation. A promising line, JS14-12-36-8-5-3-1-1-1, was developed and designated as HY103 in 2013. This variety headed on August 22, which was 11 days later than that of Hwayeong. The culm length and panicle length of Hyowon6 was 85.7 cm and 21.1 cm, respectively. The number of panicles per hill was 14.5 and the number of grains per panicle was 101.7. The ratio of ripened grain was approximately 92% and the 1,000-grain weight was approximately 21.36 g for brown rice, which were similar to those of Hwayeong. Hyowon6 was moderately resistant to lodging and also to neck blast, leaf blight, and stripe virus. The glossiness value of Hyowon6 was 83, which was considerably higher than that of Hwayeong.