• Korean Journal of Plant Resources
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• v.30 no.6
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• pp.654-661
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• 2017

Dual-color fluorescence in situ hybridization karyotype analysis was created using repetitive sequences including two types of rDNA repeats (45S and 5S rDNAs) and Arabidopsis-type telomere sequence repeats. The somatic metaphase cells of Carthamus tinctorius were observed as diploids (2n=2x=24). A symmetrical or slightly asymmetrical karyotype with seven pairs of metacentric and five pairs of submetacentric chromosomes was observed. The lengths of the somatic metaphase chromosomes ranged from 4.18 to $6.53{\mu}m$, with a total length of $60.71{\mu}m$. One locus of 45S rDNA was located on the pericentromeric regions of three pairs of chromosomes and the other pair was situated on the terminal regions of the short arms of a single pair of chromosomes. One locus of 5S rDNA was detected on the interstitial regions of the short arms of two pairs of chromosomes. Arabidopsis-type telomeric repeats were detected on the terminal regions of all pairs of chromosomes. Co-localization of loci between telomeric repeats and 45S rDNA was observed in a single pair of chromosomes. The results provide additional information for the existing physical mapping project of C. tinctorius and will also serve as a benchmark to a more intricate cytogenetic investigation of C. tinctorius and its related species.

• Korean Journal of Plant Resources
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• v.27 no.3
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• pp.249-255
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• 2014

The rice belonging to Oryza sativa is not only has significant economic importance, for it is the major source of nutrition for about 3 billion all around the world. But also plays a vital role as a model organism, because it has a number of advantages to be a model plant, such as efficient transformation system and small genome size. Many methods and techniques have been conducted to attempt to distinguish different Oryza sativa species, such as amplified fragment length polymorphism (AFLP), random amplified polymorphic DNA (RAPD), simple sequence repeat (SSR) and so on. However, studies using sequence analysis of internal transcribed spacer (ITS), a region of ribosomal RNA has not been reported until now. This study was undertaken with an aim to understand the phylogenetic relationships among sixteen isolates of Oryza sativa collected from abroad and fifteen isolates collected from Korea, using ribosomal RNA (rRNA) internal transcribed spacer (ITS) sequences to compare the phylogeny relationships among different Oryza sativa species. The size variation obtained among sequenced nuclear ribosomal DNA (nrDNA) ITS region ranged from 515bp to 1000bp. The highest interspecific genetic distance (GD) was found between Sfejare 45 (FR12) and Anapuruna (FR15). Taebong isolate showed the least dissimilarity of the ITS region sequence with other thirty isolates. This consequence will help us further understanding molecular diversification in intra-species population and their phylogenetic analysis.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.345-354
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• 2017

The leaves of two woody plant species, Pinus densiflora and Aronia melanocarpa, were collected in Korea, and endophytic fungi were isolated from these surface-sterilized leaves. The fungal isolates were identified based on their morphological characteristics and the results of the phylogenetic analysis involving nucleotide sequences of the internal transcribed spacer region (ITS), including 5.8S rDNA, D1/D2 regions of 28S rDNA, and ${\beta}-tubulin$ genes. Pestalotia lawsoniae and Zasmidium fructicola were isolated from Pinus densiflora, and three species, Pestalotiopsis chamaeropis, Pestalotiopsis jesteri, and Stagonosporopsis cucurbitacearum were isolated from Aronia melanocarpa. To the best of our knowledge, these species have not been previously reported in Korea.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.83-92
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• 2015

xBrassicoraphanus line BB#5, a new synthetic intergeneric hybrid between Brassica rapa L. ssp. pekinensis and Raphanus sativus L. var. rafiphera induced by N-methyl-N-nitroso-urethane mutagenesis in microspore culture, shows high seed fertility and morphological uniformity. Dual-color fluorescence in situ hybridization (FISH) using 5S and 45S rDNA probes and genomic in situ hybridization (GISH) using B. rapa genomic DNA probe were carried out to analyze the chromosome composition and the meiosis pairing pattern compared to its parental lines. The somatic chromosome complement is 2n = 38, which consists of 17 metacentric and two submetacentric chromosomes with lengths of 2.18 to $5.01{\mu}m$. FISH karyotype analysis showed five and eight pairs of 5S and 45S rDNA loci. GISH meiosis pairing analysis showed that 19 complete bivalents were most frequent and accounted for 42% of the 100 pollen mother cells examined. Based on chromosome number, size, morphology, rDNA distribution, and meiosis pairing pattern, both parental genomes of B. rapa and R. sativus appear to exist in xBrassicoraphanus line BB#5, demonstrating its genome integrity. Such stable chromosome constitutions and meiotic pairing patterns in somatic and meiotic cells are very rare in natural and synthetic intergeneric hybrids. Chromosomal studies and genetic and phenotypic changes in allopolyploids a re discussed. The results p resented h erein will b e usef ul f or f urther g enomic s tudy o f xBrassicoraphanus lines and their improvement as promising new breeding varieties.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.101-108
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• 2006

YNB54 strain which shows inhibitory activities specific to the plant pathogenic Phytophthora sp. on potato dextrose agar medium was screened among lots of strains isolated from Korean soils. To identify taxonomy of the Phytophthora specific antagonistic bacteria YNB54, 165 rDNA sequence, MIDI fatty acid composition, DNA-DNA hybridization, GC content, and commercial multitest systems such as API 20E and Biolog GN were performed. Results of commercial kits including lots of biochemical and physiological reactions showed that this strain was closely related to taxa including Enterobacter cloacae and Enterobacter cancerogenus species than other genera(Citerobacter Klebsiella, Leclercia). Also, analysis of its MIDI, G+C contents, and DNA-DNA hybridization suggests that this strain was more similiar to the Genus Enterobacter than other genera (Citerobacter Klebsiella, Leclercia). This strain was potentially identified as Enterobacter sp. by these results. But our 16S ribosomal DNA sequences (rDNA) analysis confirmed that it was more closely related to the cluster of Citerobacter freundii ATCC 29935 than any other Enterobacter species. In the absence of defined phylogenetic critia for delineating genera, the results observed with Citrobacter and Enterobacter species suggest that further studies are needed to clarify their relationships. This investigation demonstrates that YNB54 strain is genetically diverse and potentially more taxonomically complex than hitherto realized. Further study is necessary to confirm their taxonomic positions.

• Mycobiology
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• v.30 no.4
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• pp.197-201
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• 2002

Specific primer sets based on ribosomal DNA(rDNA) internal transcribed specer(ITS) sequences were designed for rapid detection of Phellinus linteus and P. baumii. Polymerase chain reaction(PCR) with these primers produced unique bands for each Phellinus species. The annealing temperature range is from $40^{\circ}C\;to\;55^{\circ}C$. The length of PCR products(P. linteus and P. baumii) using designed combinative primer sets of PL1F, PL2R, PB1F, PB2R, ITS5F and ITS4R, were from 520 by to 730 bp. Fifteen strains of Phellinus species including P. linteus, P. baumii, P. weirianus, P. johnsonianus, P. rhabarberinus, P. pini, P. gilvus, P. igniarius, P. nigricans and P. laevigatus were examined in this study. Five strains, including two isolated strains of P. linteus(MPNU 7001 and MPNU 7002), and two isolated strains of P. baumii(MPNU 7004 and MPNU 7005) were shown to have about 520 bp (PL1F-PL2R), 700 bp (TTS5F-PL2R) and 600 bp (PB1F-ITS4R) -sized PCR single bands respectively. This molecular genetic technique provided a useful method for rapid detection and identification of P. linteus and P. baumii.

• Research in Plant Disease
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• v.18 no.2
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• pp.73-79
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• 2012

Phytophthora katsurae is a fungal pathogen responsible for chestnut ink disease. We designed two duplex primer sets (SOPC 1F/1R+KatI 3F/5R, SOPC 1-1F/1-1R+KatI 3F/5R) to detect P. katsurae. SOPC 1F/1R and SOPC 1-1F/1-1R primer pairs were designed for sequence characteristic amplification regions (SCAR) marker, and KatI 3F/5R primer pair was used for P. katsurae-specific primer designed from internal transcribed spacer (ITS) region. To assess the sensitivity of duplex PCR, genomic DNA was serially diluted 10-fold to make the final concentrations from 1 mg/ml to 1 ng/ml. The sensitivity for two primer sets were 1 ${\mu}g/ml$ and 100 ng/ml, respectively. To find detection limits for zoospores of P. katsurae, each zoospore suspension was serially diluted 10-fold to make the final concentrations from $1{\times}10^6$ to $1{\times}10^2$ cells/ml, and then DNA was extracted. The limits of detection for all of two primer sets were $1{\times}10^5$ cells/ml. All of two primer sets were specific to P. katsurae in PCR detection and did not produce any P. katsurae-specific PCR amplicons from other 16 Phytophthora species used as the control. This study shows that duplex PCR using two primer sets might be a useful tool for rapid and efficient detection of P. katsurae.

• Journal of Sericultural and Entomological Science
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• v.41 no.3
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• pp.174-179
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• 1999

The genetic relationships among six Cordyceps spp. were investigated based on internal transcribed spacer sequences of ribosomal DNA .A portion of the these genes was amplified by PCR. Approximately 590 base pairs were successfully amplified, cloned, sequenced, compared. The nucleotide sequence of the six amplified fragments were aligned by the clustal W program. As a result, Cordyceps militaris shared 87, 96, 98, 90 and 97% sequences homology with Paecilomyces japonica, Paecilomyces sp. J300, Paeciomyces farinosa. Paecilomyces sp. J500 and Cordyceps sinensis, respectively. Paecilomyces japonica also shared 87, 88, 92 and 87% sequence similarity with Paecilomyces sp. J300, Paecilomyces farinosa, Paecilomyces sp. J500 and Cordyceps sinensis, repectively.

• Korean Journal of Veterinary Research
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• v.43 no.1
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• pp.139-144
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• 2003

A chitinase cDNA named CHT1 was cloned from the hard tick, Haemaphysalis longicornis, and the enzymatic properties of its recombinant proteins were characterized. The CHT1 cDNA encodes 930 amino-acid (aa) residues including a 22 aa putative signal peptide, with the calculated molecular mass of the putative mature protein 104 kDa. The E coli-expressed rCHT1 exhibited weak chitinolytic activity against $4MU-(GlcNAc)_3$. The rCHT1 protein with higher activity was obtained using recombinant Autographa californica multiple nuclear polyhedrosis virus (AcMNPV), which expresses rCHT1 under polyhedrin promoter. These findings suggest that the rCHT1 expressed in baculovirus-mediated Sf 9 cells has a high activity than E coli-expressed rCHT1.

• Research in Plant Disease
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• v.10 no.1
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• pp.63-68
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• 2004

Twenty-three strains of Serratia sp., isolated from surface-sterilized rice roots collected in Chonbuk and Chungnam province, were identified and characterized. They were Gram-negative, rod shaped and red pigmented typically and their endophytism was confirmed by inoculation and reisolation of the strains in planta. Their antifungal activity against 4 rice pathogenic fungi was compared and ranged from 62.4 to 85.2％ against Rhizoctonia solani and 68.0 to 88.5％ against Pyricularia grisea. Among the 23 strains tested, strain Rsm220 showed the strongest inhibition activity against 4 pathogenic fungi. The strain was, therefore, selected as a biocontrol candidate for both the pathogens and its bacteriological characteristics and 165 rDNA sequences were analyzed. Phenotypic and biochemical characteristics of the selected Rsm220 were highly related to the type strain of S. marcescens and 165 rDNA sequencing of Rsm220 showed a homology of 98.2％ to the type strain of S. marcescens. The strain Rsm220 was identified as S. marcescens and the inhibition result of this endophytic strain indicates that it is a potential biocontrol agent for R. solani and R grisea.