• International Journal of Industrial Entomology and Biomaterials
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• v.17 no.2
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• pp.211-215
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• 2008

To select entomopathogenic fungi controlling aphids effectively, several isolates were screened against second instars of Myzus persicae nymphs in the glasshouse using conidia suspension at $1.0{\times}10^5$ conidia/ml. Among these isolates, SFB-205 conidia showed the highest insecticidal activity about 32.7% efficacy to M. persicae at 4 days after application in the glasshouse. The attachment of SFB-205 conidia on the surface of M. persicae nymphs, and germination and penetration were observed using scanning electron microscopy. SFB-205 was identified as Beauveria bassiana species through the comparison of 5.8 s rRNA genes. There were 24 polymorphisms between SFB-205 and the previously reported isolate, B. bassiana ATCC74040 using six kinds of primer combinations in amplified fragment length polymorphism (AFLP) analysis. The B. bassiana SFB-205 might be used as a practical biological control agent for the green peach aphid, M. persicae in the field.

• Biomedical Science Letters
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• v.19 no.3
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• pp.213-223
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• 2013

The objectives of this study are to develop a molecular diagnosis to differentiate serotypes and mating-types of C. neoformans/C. gattii complex isolates from pigeon droppings in Korea and to elucidate molecular epidemiology of the isolates. Phenotypes and genotypes of C. neoformans/C. gattii complex isolates were identified by biochemical properties and PCR using specific CNLAC1 gene, respectively. To classify serotypes and mating-types of C. neoformans/C. gattii complex isolates, the five reference strains and thirty-three isolates in Korea were investigated by restriction fragment length polymorphism (RFLP) analysis using CNLAC1 gene for varieties, by random amplified polymorphic DNA (RAPD) for serotyping, and by PCR using specific primer sets for mating typing. All isolates in Korea were belonged to C. neoformans var. grubii (serotype A) by RFLP and RAPD patterns which showed high sensitivity and specificity. Therefore, RFLP and RFLP were available to differentiate varieties and serotypes of C. neoformans. Amplification patterns of the five reference strains by specific PCR for mating typing were differentiable, and all isolates were classified into $MAT{\alpha}$. All C. neoformans environmental isolates in Korea were Cr. neoformans serotype A and $MAT{\alpha}$ which is a more virulent pathogen. This study suggests that RFLP and RAPD are rapid and correct molecular diagnosis tools for epidemiology of C. neoformans/C. gattii complex isolates.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.184-188
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• 2009

Identification of differently expressed genes under specific tissues and/or environments provides insights into the nature and underlying mechanisms of cellular processes. Although cDNA-AFLP (Amplified Fragment Length Polymorphism) is a powerful method for analyzing differentially expressed genes, its use has been limited to the requirement of radioactive isotope use and the difficulty of isolating the bands of interest from a gel. Here, we describe a modified method for cDNA-AFLP that uses a fluorescence dye for detection and isolation of bands directly from a small size polyacrylamide gel. This method involves three steps: (i) preparation of cDNA templates, (ii) PCR amplification and differential display, and (iii) identification of differentially expressed genes. To demonstrate its utility and efficiency, differentially expressed genes during vegetative growth and appressorial development of Magnaporthe oryzae were analyzed. This method could be applied to compare gene expression profiles in a diverse array of organisms.

• Research in Plant Disease
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• v.22 no.4
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• pp.236-242
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• 2016

Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating diseases in major Solanaceae crops. The pathogen is easily disseminated and survives for many years in plant farming system. Although chemicals are applied to control the disease, they are of limited efficacy and cause several problems. Therefore, the use of phage therapy has been suggested to control the disease as a biological agent. In this study, we discovered bacteriophages lysing diverse Ralstonia isolates from plant and soil samples obtained from the potato cultivated field in Jeju. Three times repeated pickings of plaques resulted in obtaining 173 single phages showing diverse spectrum of host-specificity. With the results, 12 core phages were selected and dendrogram was generated. Genetic diversity of the selected phages was also confirmed by AFLP (Amplified Fragment of Length Polymorphism) fingerprinting. The stability of the phages was investigated in various temperatures and various conditions of pH in vitro. The phages were stable at $16^{\circ}C-44^{\circ}C$ and pH 6-10. Morphological characterization of the phages revealed they were all classified into the Podoviridae, but had diverse head sizes. The results of this research will contribute to control the disease and further researches regarding genetic and molecular aspects will facilitate understanding phage and bacteria interaction.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1822-1830
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• 2002

The microsatellites are the short tandem repeats of 1 to 6 bp long monomer sequences that are repeated several times. These short tandem repeats are considered to be generated by the slipped strand mispairing. Based on the unique capability of alternating purine-pyrimidine residues to form Z-DNA, the possible role of the microsatellites in gene regulation has been proposed. The microsatellites are highly polymorphic, follow Mendelian inheritance and are evenly distributed throughout the genomes of eukaryotes. They are easy to isolate and the polymerase chain reaction based typing of the alleles can be readily automated. These properties make them the preferred markers for comparison of the genetic structure of the closely related breeds/populations; very high-resolution genetic mapping and parentage testing etc. The microsatellites have rapidly replaced the restriction fragment length polymorphism (RFLP) and the random amplified polymorphic DNA (RAPD) in most applications in the population genetics studies in most species, including the various farm animals viz. cattle, buffalo, goat, sheep and pigs etc. More and more reports are now available describing the use of microsatellites in pigs ranging from measurement of genetic variation between breeds/populations, developing high resolution genetic maps to identifying and mapping genes of biological and economic importance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.2
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• pp.142-146
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• 2005

Thirty-two germplasms of Korean adlay landraces were examined to analyse the genetic relationship through the amplified fragment length polymorphism (AFLP) approach. Total number of AFLP products generated by 12 selective primer combinations was 882. The number of polymorphic fragments by each primer combination greatly varied from 4 to 51 with a mean of 20.3, bands visible on the polyacrylamide gel. A genetic similarity coefficient was used for cluster analysis following UPGMA (unweighted pair grouping method of averages) method. The resulting clusters were represented in the form of a dendrogram. The clustering was not tight in the dendrogram. There was generally no clear grouping of the adlay according to the geographic regions in which germplasms were collected. The present AFLP analysis imply that although Korean adlay displayed a larger amount of AFLP variation within germplasms, the variation was shown independently without reflecting a clinal variation. This study demonstrated that AFLP method can be used to examine the genetic relationships among different germplasms of adlay.

• Mycobiology
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• v.31 no.4
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• pp.229-234
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• 2003

A total of 24 isolates of Phytophthora infestans were tested and analyzed for their resistance to metalaxyl fungicides. Sensitivity to metalaxyl was determined by growing isolates on 20% V8 medium amended with 0, 5, and 100 ${\mu}g/ml$ metalaxyl. Four isolates among the 24 tested were resistant to metalaxyl. Eleven isolates were intermediate and nine isolates were sensitive. Amplified fragment length polymorphism(AFLP) assay was used to identify the amplification products of resistant isolates. As a result, selected fragments were cloned, sequences and primer pairs were developed which linked to metalaxyl insensitivity in P. infestans using competitive PCR.

• Journal of Microbiology
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• v.41 no.4
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• pp.312-319
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• 2003

In an attempt to develop a method for rapid and accurate identification of six Vibrio species that are clinically important and most frequently detected in Korea, 16S rDNA restriction fragment length polymorphism (RFLP) of Vibrio type strains, as well as environmental isolates obtained from the Korean coastal area, was analyzed using ten restriction endonucleases. Digestion of the 16S rDNA fragments amplified by polymerase chain reaction (PCR) with the enzymes gave rise to 2~6 restriction patterns for each digestion for 47 Vibrio strains and isolates. An additional 2~3 restriction patterns were observed for five reference species, including Escherichia coli, Aeromonas hydrophila, A. salmonicida, Photobacterium phosphoreum, and Plesiomonas shigelloides. A genetic distance tree based on RFLP of the bacterial species correlated well with that based on 16S rDNA sequences. The very small 16S rDNA sequence difference (0.1%) between V. alginolyticus and V. parahaemolyticus was resolved clearly by RFLP with a genetic distance of more than 2%. RFLP variation within a species was also detected in the cases of V. parahaemolyticus, V. proteolyticus, and V. vulnificus. According to the RFLP analysis, six Vibrio and five reference species were assigned to 12 genotypes. Using three restriction endonucleases to analyze RFLP proved sufficient to identify the six pathogenic Vibrio species.

• Mycobiology
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• v.32 no.3
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• pp.123-127
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• 2004

Sweet persimmons have been increasingly cultivated in the southern part of Korea. However, anthracnose disease caused by Colletotrichum species is one of the major hindrances in cultivation and productions. In this study, we used polymerase chain reaction(PCR) to detect Colletotrichum species with the AFLP(amplified fragment length polymorphism) method. In AFLP, we used E3(5'-GACTGCGTACCAATTCTA-3') and M1(5'-GATGAGTCCTGAGTAACAG-3') primer combination and, as a result, 262 bp segment was observed in Colletotrichum species only. Specific PCR primers were designed from the sequence data and used to detect the presence of the fungus in genomic DNA isolated from symptomless sweet persimmon plants. Based on sequence data for specific segments, Co.B1(5'-GAGAGAGTAGAATTGCGCTG-3') and Co.B2(5'-CTACCATTCTTCTA GGTGGG-3') were designed to detect Colletotrichum species. The 220 bp segment was observed in Colletotrichum species only, but not in other fungal and bacterial isolates.

• Korean Journal of Medicinal Crop Science
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• v.17 no.3
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• pp.198-203
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• 2009

Isatis tinctoria var. yezoensis (Ohwi) Ohwi (Cruciferae) is one of major natural dyeing crops in the world and also have used as a medicinal plant in Korea. We evaluated seed purity in $F_1$-hybrid accessions using amplified fragment length polymorphism (AFLP) markers. One hundred sixty seeds from the male and female harvests were subsequently screened for seed purity with ten primers. The 13 accession-specific bands and many variable AFLP bands scored for accessions. Especially, E-AAC/M-CAA and E-AAG/M-CAT were presented clear hybrid bands for $F_1$ hybrids. $F_1$ hybrids maintained higher average level of genetic diversity compared with their correspondent parents. Self-inbred seeds from the female and male harvests were revealed 8.0% and 5.0%, respectively. The AFLP may lead to a better insight in to the hybrid seed purity test in I. tinctoria var. yezoensis.