• Korean Journal of Agricultural Science
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• v.43 no.2
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• pp.221-231
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• 2016

Microsatellites, which are sequences of repetitive short nucleotides, are abundant in the genome and have relatively many alleles at a locus. Hence, microsatellite markers are used in various research areas such as medicine, agriculture, and biology. Thanks to recent advanced techniques and databases associated with microsatellite marker development, foreign research relying on microsatellite markers is increasing in various study areas. In this study, by analyzing microsatellites-related articles published during 2000-2014 from eight Korean national journals representing zoology, botany, genetics, ecology and environmental science, breeding science, and forest science ('Animal Cells and Systems', 'Journal of Plant Biology', 'Genes and Genomics', 'Korean Society of Environment and Ecology', 'Korean Journal of Breeding Science', 'Journal of Agricultural Science, Chungnam National University', 'Journal of Korean Forest Society' and 'Forest Science and Technology'), we found that the number of articles and diversity of study subjects and objects have increased considerably. However, there are fewer applications of microsatellites in the national forest science area. During 2000-2014 in 'Journal of Korean Forest Society', the percentage of articles dealing with microsatellite markers was found to be the lowest with 4.2% among articles focusing on PCR-based markers including RAPD, AFLP, and ISSR. However, in 'Canadian Journal of Forest Research' and 'Forest Ecology and Management', microsatellite marker articles were represented at their highest with 69.2% and 76.2%, respectively. Given the advantages of microsatellite markers, the publication of research papers using microsatellites should be increased in Korean forest science journals to the level of studies published in prominent international journals.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.262-269
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• 2005

An antiviral producing bacterial strain was isolated from a ginseng rhizosphere in Kangwon province of Republic of Korea. In order to identify the bacterial strain, microbiological, physiological and biochemical tests were performed, along with RAPD, 16S rRNA, 16S-23S rRNA ITS (intergenic spacer region) and DNA-DNA hybridization analyses. The bacterium was found to be a strain of Pseudomonas fluorescens, which was designated as Gpf01. The strain was grown in Muller-Hinton (MH) broth, and the culture supernatant obtained was filtered through a $0.45{\mu}l$ filter. It was further boiled at $100^{\circ}C$ and tested in two experiments for its ability to control a yellow strain of Cucumber mosaic virus (CMV-Y). In the first experiment, boiled culture filtrate (RCF) was treated on one half of the leaves of Chenopodium amaranticolor followed by CMV- Y inoculation on both halves. In the second experiment, BCF was treated on the lower leaves of Nicotiana tobacum var. Xanthi-nc, with the CMV-Y mechanically inoculated onto the upper untreated leaves. In the first experiment, BCF treatment was able to considerably reduce the number of viral lesion, and in the second experiment, plants treated with BCF showed no visible viral symptoms compared to the Muller-Hinton (MH) media treated controls 15 days post inoculation (dpi), and remained symptomless throughout the study period. Thus, Gpf01, identified as P. fluorescence, was able to produce an antiviral component in the culture filtrate, which was found to be heat stable, non-phytotoxic and effective in local as well as systemic hosts of CMV.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.269-278
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• 2008

Ripe rot was frequently observed on fruits, leaves and stems of grape growing in eight locations in Korea from 2004 to 2006. All 30 isolates of Colletotrichum sp. were obtained from lesions of the ripe rot on grape plants. Out of the isolates, 19 isolates were identified as Colletotrichum acutatum and the others as Colletotrichum gloeosporioides based on morphological and cultural characteristics. Inter and intra specific variations of the Colletotrichum spp. isolates were investigated using RAPD and sequences of rDNA ITS and $\beta$-tubulin-2. Isolates of C. acutatum and C. gloeosporioides were distinctly differentiated by molecular analyses. Phylogenetic trees of ITS and$\beta$-tubulin-2 showed that Korean isolates of C. acutatum were clustered into groups A2 and A3 among the eight global groups. A2 included non-chromogenic isolates and A3 chromogenic ones. Both C. acutatum and C. gloeosporioides isolates were tested for pathogenicity to grape leaves. All isolates tested induced lesions on the leaves of grape by artificial inoculation. There was no difference in pathogenicity between C. acutatum and C. gloeosporioides isolates. This is the first report that C. acutatum except C. gloeosporioides causes grape ripe rot in Korea.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.106-111
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• 2005

For breeding of a new rootstock for eggplant production, somatic hybrids between two species, Solanum integrifolium and S. sanitwongsei were obtained through protoplast fusion. The former species has been commonly used for rootstock for eggplant production in Japan. Eggplants on these rootstocks are more productive than ungrafted plants, but are susceptible to bacterial wilt caused Ralstonia solanacearum. While the latter species is resistant, the growth of eggplants on this rootstock is rather slow and low yield. Protoplast of both species were isolated from cotyledons, and inactivated with iodoacetamide or UV-irradiation, then fused electrically. The fused products were then cultured. Regenerated plantlets were then transplanted on soil then maintained in a green house. The plants were classified into four groups. Those in the first group showed morphological characters intermediate of the parentalspecies. The plants bore fruit with viable seeds. The plants showed a chromosome number of 2n=48, the sum of those of the parental species, and are suggested to be symmetric fusion products. While plants in the other groupswas less vigorous and showed chromosome number 2n= 68 to 72 suggesting asymmetric fusion products by genomic in situ hybridization(GISH). Isozyme pattern of shikimate dehydrogenase (SKDH; EC 1.1.1.25), isocitrate dehydrogenase (IDH; EC 1.1.1.41) and phosphoglucomutase (PGM; EC 2.7.5.1) showed that 24 regenerated plants in three groups were somatic hybrids. Analysis of random amplified polymorphic DNA (RAPD) showed that 43 S. integrifolium-specific and 57 S. sanitwongsei-specific bands were all found in 24 plants. Both somatic hybrids and its S1 plants were found to be resistant to bacterial wilt, and eggplant grafted these plants using for rootstocks were more productive than grafted mother plants. Now, S1 progenies are used for commercial eggplant production in Osaka Prefecture.

• Journal of Aquaculture
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• v.19 no.2
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• pp.67-76
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• 2006

Genomic DNA isolated from two Porphyra species, P. tenera and P. dentate from Wando located on the southern coast of Korean peninsula was amplified by PCR reaction. The amplified products were separated by agarose gel electrophoresis (AGE) with decamer primer and stained with ethidium bromide. The eight arbitrarily selected primers OPA-04, OPA-06, OPB-01, OPB-08, OPB-10, OPB-11, OPB-14 and OPC-10 generated the shared loci, polymorphic, and specific loci. The size of DNA bands varies from 100 bp to 2,200 bp. The complexity of the banding patterns varies dramatically between the primers and two Porphyra species. A total of 528 loci observed were identified in P. tenera and 443 in P. dentata: 22 polymorphic loci (4.2%) in P. tenera and 30 (6.8%) in P. dentata. 154 shared loci observed, the average 19.3 per primer, were identified in P. tenera and 143 loci, the aver-age 17.9 per primer, in P. dentata species. The number of specific loci in P. tenera and P. dentata was 73 and 77, respectively. The average bandsharing value was $0.623{\pm}0.008$ with P. tenera and $0.560{\pm}0.009$ within P. dentata. The average bandsharing value between two Porphyra species was $0.408{\pm}0.004$, ranged from 0.305 to 0.564. The dendrogram obtained by the eight primers indicates four genetic clusters. The genetic distance between two Porphyra species ranged from 0.076 to 0.627. The individual no. 02 of P. tenera was genetically closely related to no. 01 of P. tenera(genetic distance=0.082). Especially, two entities between the individual DENTATA no.21 and DENTATA no. 19 of P. dentata showed the longest genetic distance (0.627) in comparison with other individuals used. In this study, RAPD-PCR analysis has revealed the significant genetic distance between two Porphyra species pairs (P<0.001).

• Journal of Microbiology and Biotechnology
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• v.9 no.6
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• pp.778-783
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• 1999

Campylobacter is a pathogen for both humans and animals that can be transferred from animals to humans. Four isolates, which grew under 5-10% $CO_2$ and had small and translucent colonies, were obtained from swine gastric mucosa and characterized using various methods. These bacteria were gram negative, spirally shaped with round ends. One or two non-sheathed polar flagella were observed under electron microscopy. A PCR with species-specific protein (SSP) primers for 16S rRNA gene in Campylobacter produced a typical 462 bp fragment. The isolates had various biochemical and molecular characteristics which differentiated them from other Campylobacters. The isolates were catalase and oxidase positive, urease (rapid) negative, nitrate reduction positive, indoxyl acetate hydrolysis positive, y-glutamyl transpeptidase negative, and alkaline phosphatase negative. All four isolates showed growth at $37^{\circ}C{\;}and{\;}42^{\circ}C{\;}but{\;}not{\;}at{\;}25^{\circ}C$, were resistant to cephalotin and cefoperazone, and susceptible to carbenicillin. The isolates showed various results in the reduction of chloride to triphenyl tetrazolium (TTC) and a susceptibility to nalidixic acid. Western blot analysis of these isolates with antiserum raised against one isolate showed different patterns from those of reference strains. A dendrogram drawn with the RAPD results showed that these isolates belonged to a new Campylobacter spp. group different from those of C. jejuni, C. doylei, C. lari, and C. coli.

• Journal of Microbiology and Biotechnology
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• v.22 no.4
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• pp.437-447
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• 2012

Natural and beneficial associations between plants and bacteria have demonstrated potential commercial application for several agricultural crops. The sunflower has acquired increasing importance in Brazilian agribusiness owing to its agronomic characteristics such as the tolerance to edaphoclimatic variations, resistance to pests and diseases, and adaptation to the implements commonly used for maize and soybean, as well as the versatility of the products and by-products obtained from its cultivation. A study of the cultivable bacteria associated with two sunflower cultivars, using classical microbiological methods, successfully obtained isolates from different plant tissues (roots, stems, florets, and rhizosphere). Out of 57 plant-growth-promoting isolates obtained, 45 were identified at the genus level and phylogenetically positioned based on 16S rRNA gene sequencing: 42 Bacillus (B. subtilis, B. cereus, B. thuringiensis, B. pumilus, B. megaterium, and Bacillus sp.) and 3 Methylobacterium komagatae. Random amplified polymorphic DNA (RAPD) analysis showed a broad diversity among the Bacillus isolates, which clustered into 2 groups with 75% similarity and 13 subgroups with 85% similarity, suggesting that the genetic distance correlated with the source of isolation. The isolates were also analyzed for certain growth-promoting activities. Auxin synthesis was widely distributed among the isolates, with values ranging from 93.34 to 1653.37 ${\mu}M$ auxin per ${\mu}g$ of protein. The phosphate solubilization index ranged from 1.25 to 3.89, and siderophore index varied from 1.15 to 5.25. From a total of 57 isolates, 3 showed an ability to biologically fix atmospheric nitrogen, and 7 showed antagonism against the pathogen Sclerotinia sclerotiorum. The results of biochemical characterization allowed identification of potential candidates for the development of biofertilizers targeted to the sunflower crop.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.328-333
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• 1999

Susceptibility of 61 strains of Helicobacter pylori to metronidazole was examined by both the disk diffusion method using a cut-off of 15㎜ for resistance and the E test with a cut-off of 8㎎/l. The MIC/sub 50/ and MIC/sub 90/ by the E test were 2 ㎎/l and 256㎎/l, respectively. Metronidazole resistance was found in 22 (36％) out of the 61 H. pylori strains by the E test and in three additional strains by the disk diffusion method. Amongst the latter three isolates, the MICs by the E test were 4 ㎎/l, 6㎎/l, and 6㎎/l, respectively. These figures are one log₂ or half log₂ dilution lower than the cut-off of 8㎎/l recommended as resistance for the E test. All 22 metronidazole resistant H. pylori isolates by the E test that were subjected to random amplified polymorphic DNA (RAPD) fingerprinting showed different DNA fingerprints. Interestingly, >90％ of resistant isolates possess two common DNA bands of 0.4 and 0.9 kb. This study demonstrates that the results of the disk diffusion method for testing H. pylori susceptibility to metronidazole correlates well with that of the E test. The criteria for interpretation need to be internationally standardized so that the results from different centers can be compared.

• Journal of Mushroom
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• v.8 no.1
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• pp.27-32
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• 2010

This study was carried out to analyze the genetic relationships among 22 strains of Sparassis crispa, which were collected from various regions of worldwide. The cleaved amplified polymorphic sequence were obtained from the ribosomal DNA ITS regions of each strain. Based on the sequence analysis, the presence of five different groups were observed. Most strains shared the high nucleotide sequence similarity (about 90%) to each other, except only one strain, KACC50866. Nucleotide sequence similarity of KACC50866 was below 10% to other strains, indicating the genetic relatedness of strain KACC50866 was low compared to other strains. More works such as mitochondria genome analysis should help to determine the precise genetic diversity of S. crispa strains.

• Applied Biological Chemistry
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• v.40 no.5
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• pp.369-374
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• 1997

An endochitosanase-producing bacterium was isolated from soil and identified as a strain of Bacillus sp. The isolate was gram positive, rod shape $(0.4-0.6{\times}1.6-2.2{\mu}m)$, endospore-forming, catalase positive, and mobility positive, and grown at pH 4.5-11.0 and upto $42^{\circ}C$ in the medium containing 2% NaCl. RAPD analysis of the DNA purified from the strain was also performed, and the chitosanase-producing strain was named as Bacillus sp. P16. The culture supernatant of the strain showed strong liquefaction activity and rapidly decreased viscosity of chitosan solution. By TLC and HPLC, chitooligosaccharides of DP 2-7 were separated and identified from the enzyme hydrolyzates of chitosan. The chitosanase from Bacillus sp. P16 was thus regarded as an endo-splitting type.