• Research in Plant Disease
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• v.24 no.1
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• pp.75-80
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• 2018

From 2014 to 2016, Fusarium wilt disease was found on fassionfruit in Iksan and Jeju, Korea. Symptoms included wilting of foliage, drying and withering of leaves, and stunting of the plants. The infected plants eventually died during growth. Colonies on potato dextrose agar were pinkish white, and felted with cottony and aerial mycelia with 35 mm after one week. Macroconidia were falcate to almost straight, thin-walled and usually 2-3 septate. Microconidia were usually formed on monophialides of the hyphae and were hyaline, smooth, oval to ellipsoidal, aseptate or medianly 1-septate, very occasionally 2-septate, slightly constricted at the septa, $3-12{\times}2.5-6{\mu}m$. On the basis of the morphological characteristics and phylogenetic analyses of two molecular markers, internal transcribed spacer rDNA and translation elongation factor $1{\alpha}$, the fungus was identified as Fusarium oxysporum. Pathogenicity of a representative isolate was proved by artificial inoculation, fulfilling Koch's postulates. To our knowledge, this is the first report on the occurrence of F. oxysporum on fassionfruit in Korea.

• Korean Journal of Clinical Laboratory Science
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• v.52 no.3
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• pp.229-236
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• 2020

Sixty-five molds isolated from clinical specimens were included in this study. All the isolates were molds that could be identified morphologically, strains that are difficult to identify because of morphological similarities, and strains that require species-level identification. PCR and direct sequencing were performed to target the internal transcribed spacer (ITS) region, the D1/D2 region, and the β-tubulin gene. Comparative sequence analysis using the GenBank database was performed using the basic local alignment search tool (BLAST) algorithm. The fungi identified morphologically to the genus level were 67%. Sequencing analysis was performed on 62 genera and species level of the 65 strains. Discrepancies were 14 (21.5%) of the 65 strains between the results of phenotypic and molecular identification. B. dermatitidis, T. marneffei, and G. argillacea were identified for the first time in Korea using the DNA sequencing method. Morphological identification is a very useful method in terms of the reporting time and costs in cases of frequently isolated and rapid growth, such as Aspergillus. When molecular methods are employed, the cost and clinical significance should be considered. On the other hand, the molecular identification of molds can provide fast and accurate results.

• The Korean Journal of Mycology
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• v.26 no.4 s.87
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• pp.466-477
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• 1998

Twenty-two Phellinus strains were characterized using colony morphologies and polymerase chain reaction (PCR) to divide into Phellinus linteus. There were some differences in mycelial growth and colony shapes among the strains when they were grown on various media such as PDA, MCM, MEA and YM. Phellinus linteus was slowly growing, formed golden-yellow colony, and produced blue pigment on PDA media. When the regions of internal transcribed spacer (ITS) were amplified from ribosomal RNA (rRNA) coding genes of P. igniarius and P. linteus strains by means of PCR, two types of band (700 bp and 800 bp) were appeared, respectively. For the amplified intergenic region I (IGRI), P. igniarius strains showed a different band among 500, 600, 700 and 800 bp according to the strains, whereas P. linteus strains did one specific band of 700 bp. By polymorphism analysis after digesting the amplified products with 6 different restriction enzymes, a band specific to P. linteus was generated when the products for ITS region were digested with HaeIII, suggesting that the enzyme digestion could provide effective method to distinguish between P. igniarius and P. linteus. And also, the analysis of genetic relationship showed that the genetic similarities were 89% and 95% in P. igniarius and P. linteus strains, respectively. Random amplification polymorphic DNA (RAPD) analysis using multiple primer sets and arbitrarily primed PCR (AP-PCR) with ITS3 primer could also result in a reproducible way to identify P. linteus strains.

• The Korean Journal of Mycology
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• v.48 no.1
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• pp.15-27
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• 2020

In screening for antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) KCCM 40510 and Bacillus cereus KCTC 3624, NNIBRFG5039 was isolated from the air in Sangju-si, Gyeongsangbuk-do. Based on a high sequence similarity of the internal transcribed spacer (ITS) region, NNIBRFG5039 was determined to be closely related to Penicillium rubefaciens CBS 139145. The optimal media, initial pH, and temperature for mycelial growth and antimicrobial activity of P. rubefaciens NNIBRFG5039 were determined as follows: potato dextrose broth (PDB), pH 6.5, and 30℃, respectively. Under the optimal culture conditions, maximum mycelial growth (12.4 g L^-1) and antibacterial activity (7.5 mm zone of inhibition against MRSA KCCM 40510, and 5.0 mm zone of inhibition against B. cereus KCTC 3624) were observed in a 5 L stirred-tank fermenter. We also isolated the antimicrobial compound from an ethyl acetate fraction, and its chemical structure was identified as (S)-6-hydroxymellein (1) by ESI-MS, ¹H-NMR, and ¹³C-NMR. Consequently, the extract from P. rubefaciens NNIBRFG5039 may be used in functional materials for antimicrobial-related applications.

• Research in Plant Disease
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• v.19 no.3
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• pp.229-232
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• 2013

Sclerotium rot of cucumber (Cucumis sativus L.) occurred at the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services in July 2012. The typical symptoms included wilt, rot, and water-soaking on stems and fruits and severely infected plants eventually died. White mycelial mats spread over lesions, and then sclerotia were formed on fruit and near soil line. The sclerotia were globoid in shape, white to brown in color and 1-3 mm in size and the hyphal width was 4-8 ${\mu}m$. The optimum temperature for mycelial growth and sclerotia formation on PDA was $30^{\circ}C$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. For further identification, the complete internal transcribed spacer (ITS) rDNA region was amplified and sequenced. On the basis of mycological characteristics, ITS rDNA region comparison, and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii Saccardo. This is the first report of sclerotium rot on cucumber caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.19 no.3
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• pp.226-228
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• 2013

In 2012, a pink mold rot was observed on unishiu orange (Citrus unshiu Mac.) fruits at the Wholesale Market for Agricultural Products, Jinju, Korea. The symptom on unishiu orange was a water-soaked lesion on the surface of fruit, which later on enlarged to form softened brown rot lesions. The diseased fruits were covered with pink-colored mold, consisting of conidia and conidiophores of the pathogen. Optimum temperature for mycelial growth was $25^{\circ}C$. Conidia were hyaline, smooth, 2-celled, and thick-walled conidia with truncate bases, ellipsoidal to pyriform, characteristically held together zig-zag chains and $12-26{\times}8-12{\mu}m$ in size. Conidiophore was erect, colorless, unbranched, and 4-5 ${\mu}m$ wide. On the basis of mycological characteristics, pathogenicity test, and molecular analysis with complete ITS rDNA region, the causal fungus was identified as Trichothecium roseum (Pers.) Link ex Gray. This is the first report of pink mold rot caused by T. roseum on unishiu orange in Korea.

• Research in Plant Disease
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• v.23 no.1
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• pp.56-59
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• 2017

During growing season of 2011 to 2013, Sclerotinia rot symptoms consistently have been observed on basil in Yesan-gun, Chungcheongnam-do in Korea. The typical symptom formed initially brownish spot on leaf and stem, and then advancing margins, wilting the whole plant and blighting, eventually died. On the surface of diseased lesions was observed cottony, white, dense mat of mycelial growth, and sclerotia ($30-100{\mu}m$ diameter) formed on stem and leaf. Morphological and cultural characteristic on potato dextrose agar, color of colony was white and colorless chocolate, sclerotium of irregular shape of the oval was black and $5-50{\mu}m$ diameter in size. In pathogenicity test, necrosis and wilt of the inoculated stem were observed in all plants and the pathogen was reisolated from stems. On the basis of mycological characteristics, pathogenicity, and internal transcribed spacer rDNA sequence analysis, this fungus was identified as Sclerotinia sclerotiorum. This is the first report of Sclerotinia rot on basil caused by S. sclerotiorum in Korea.

• Parasites, Hosts and Diseases
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• v.53 no.4
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• pp.395-402
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• 2015

Non-human primates (NHPs) are confirmed as reservoirs of Cryptosporidium spp., Giardia intestinalis, and Enterocytozoon bieneusi. In this study, 197 fresh fecal samples from 8 NHP species in Qinling Mountains, northwestern China, were collected and examined using multilocus sequence typing (MLST) method. The results showed that 35 (17.8%) samples were positive for tested parasites, including Cryptosporidium spp. (3.0%), G. intestinalis (2.0%), and E. bieneusi (12.7%). Cryptosporidium spp. were detected in 6 fecal samples of Macaca mulatta, and were identified as C. parvum (n=1) and C. andersoni (n=5). Subtyping analysis showed Cryptosporidium spp. belonged to the C. andersoni MLST subtype (A4, A4, A4, and A1) and C. parvum 60 kDa glycoprotein (gp60) subtype IId A15G2R1. G. intestinalis assemblage E was detected in 3 M. mulatta and 1 Saimiri sciureus. Intra-variations were observed at the triose phosphate isomerase (tpi), beta giardin (bg), and glutamate dehydrogenase (gdh) loci, with 3, 1, and 2 new subtypes found in respective locus. E. bieneusi was found in Cercopithecus neglectus (25.0%), Papio hamadrayas (16.7%), M. mulatta (16.3%), S. sciureus (10%), and Rhinopithecus roxellana (9.5%), with 5 ribosomal internal transcribed spacer (ITS) genotypes: 2 known genotypes (D and BEB6) and 3 novel genotypes (MH, XH, and BSH). These findings indicated the presence of zoonotic potential of Cryptosporidium spp. and E. bieneusi in NHPs in Qinling Mountains. This is the first report of C. andersoni in NHPs. The present study provided basic information for control of cryptosporidiosis, giardiasis, and microsporidiosis in human and animals in this area.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.151-156
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• 2017

Summer patch is the most serious disease at turfgrass field or golf course established with Kentucky bluegrass during high temperature season in Korea. Nevertheless, chemicals for the summer patch control are not yet registered in Korea. We isolated the pathogens from the turfgrass showing typical summer patch symptoms and identified as Magnaporthiopsis poae by using the internal transcribed spacer ITS1 and ITS4 sequences of rDNA. The inhibition rates of the pathogen were investigated for 10 fungicides. As results, the pathogen growth was suppressed when chemicals concentration increased and negatively correlated with incubation period with the chemicals. In triazole group, all chemicals (metconazole, myclobutanil, propiconazole and tebuconazole) treated showed the inhibition rates by 100%. Thiophanate-methyl showed the next highest inhibition effect against a summer patch pathogen. In strobilurin group, pyraclostrobin was the highest suppression effect compared with azoxystrobin and trifloxystrobin. Inhibition effect of fludioxonil and fluxapyroxad on pathogen was similar to the trifloxystrobin. Based on the results, triazole and carboxamide groups are strongly recommended due to the highest inhibition effect on the summer patch pathogen, Magnaporthiopsis poae.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.740-747
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• 2013

Leaf mold symptoms were found on commercial tomato cultivars carrying the Cf-9, a resistance gene to leaf mold pathogen Fulvia fulva in 2012 at Buyeo, Chungnam in Korea. Fifteen-fungal isolates were obtained from four Cf-9 cultivars of tomato including 'Cutie', 'otaerangdia', 'Unicorn' and 'Rapito'. Due to their same morphological appearances and colony color, nine isolates were selected and identified as F. fulva based on molecular analysis of the internal transcribed spacer rDNA sequence. Pathogenicity of the 15 isolates on five commercial cultivars carrying Cf-4, Cf-5, and Cf-9 were tested. All the isolates showed strong pathogenicity on Cf-9 cultivars, 'Cutie' and 'Dotaerangdia', and Cf-5 cultivar, 'Yoyocaptain'. In contrast, on Cf-4 cultivar, 'Superdotaerang', five isolates were virulent and the other isolates were not. In addition, two fungal isolates, infecting Cf-9 cultivar and non-infecting Cf-4 cultivar, were selected and their pathogenicity was tested on 17 commercial cultivars reported as tomato having Cf-9 resistance gene. Among them, 15 cultivars were susceptible and 2 cultivars were resistant. It is likely that the two cultivars include other resistance gene. To our knowledge, this is the first report on the occurrence of Cf-9 infecting F. fulfva strains in Korea.