• The Korean Journal of Mycology
• /
• v.51 no.2
• /
• pp.147-153
• /
• 2023

Dark brown leaf molds growing in a vein-limited pattern have been continuously observed on the lower leaf surface of Fatoua villosa in Korea. Fifteen samples deposited in the Korea University herbarium were examined for fungal morphological characterization. Two monoconidial isolates were obtained in 2022, and molecular analysis was performed based on a combined multigene dataset of the internal transcribed spacer (ITS) region and partial actin (actA), translation elongation factor 1-alpha (tef1), and DNA-directed RNA polymerase II second-largest subunit (rpb2). Based on morphological features and molecular phylogenetic analysis, the fungus Pseudocercospora fatouae was identified. To the best of our knowledge, it is the first study reporting the presence of P. fatouae on F. villosa in Korea.

• Research in Plant Disease
• /
• v.25 no.4
• /
• pp.213-219
• /
• 2019

A total of 1,159 Fusarium strains were isolated from sorghum grown in Danyang and Youngwol in 2017 and 2018. The isolates were analyzed to reveal genetic, toxigenic and pathogenic characteristics. Phylogenetic analysis using TEF-1α and RPB2 genes showed that the samples were contaminated with at least 17 Fusarium species. Among them, F. graminearum, F. proliferatum, F. thapsinum, F. incarnatum, and F. asiaticum were dominant species. In F. graminearum and F. asiaticum, F. graminearum-15-acetyl deoxynivalenol chemotype and F. asiaticum-nivalenol chemotype were frequent. Six Fusarium species tested produced one or more mycotoxins, except F. thapsinum and FTSC 11. F. proliferatum and F. fujikuroi had FUM1 gene (76.0% and 81.6%, respectively) and some isolates produced high level of fumonisin (over 1,000 ㎍). F. proliferatum and F. thapsinum were more virulent than other species on sorghum. These results indicate that Fusarium species in sorghum might produce multiple mycotoxins.

• Research in Plant Disease
• /
• v.20 no.4
• /
• pp.245-252
• /
• 2014

The study was performed to establish an efficient screening method for resistant cucumber to Fusarium oxysporum f. sp. cucumerinum. The isolate KR5 was identified as F. oxysporum f. sp. cucumerinum based on molecular analyses of ITS and TEF genes and host-specificity test on cucurbits including melon, oriental melon, cucumber, and watermelon. Then four cucumber and two rootstock cultivars showing different resistance degrees to the Fusarium wilt pathogen KR5 were selected. And development of Fusarium wilt of the six cultivars according to several conditions, including incubation temperature after inoculation, inoculum concentration, root wounding, and growth stages of seedlings, was investigated. Disease severity of Fusarium wilt on the resistant cultivars was changed with incubation temperatures after inoculation. The resistant cultivars showed the higher resistance when inoculated plants were kept at 25 or $30^{\circ}C$ than at $20^{\circ}C$. Among four different growth stages of the seedlings, seven-day-old seedling represented the most difference of resistance and susceptibility to Fusarium wilt. From above results, we suggest that an efficient screening method for resistant cucumber to F. oxysporum f. sp. cucumerinum is to dip the non-cut roots of seven-day-old seedlings in spore suspension of $1.0{\times}10^6-1.0{\times}10^7$ conidia/ml and to transplant the seedling into a non-infected soil, and then to incubate the inoculated plants in a growth room at $25^{\circ}C$ for 3 weeks to develop Fusarium wilt.

• The Korean Journal of Food And Nutrition
• /
• v.30 no.3
• /
• pp.501-509
• /
• 2017

This study investigated the quality characteristics and antioxidant activities of gluten-free cookies containing teff flour. By substituting 0% (control), 25% (TF25), 50% (TF50), 75% (TF75), and 100% (TF100) of wheat flour with teff flour, five samples were produced. Baking loss rate was the highest in TF25 at 13.76% and the lowest in TF75 at 4.03%. Spread factor was significantly higher in cookies made with teff flour (83.00~85.00) than in the control (81.33) (p<0.05). There was no significant difference in density among the samples at 1.17~1.25 g/mL (p<0.05); however, pH significantly decreased at 6.42~6.04 (p<0.05). While the L-value and b-value significantly decreased with the amount of teff flour, the a-value significantly increased (p<0.05). The ${\Delta}E$ value was the highest in the control at 31.31 and the lowest in TF100 at 58.69. Hardness was the highest in the control at 42.04 N than in cookies containing teff flour. The content of polyphenols was the highest in TF100 at $3.37{\mu}g\;GAE/mg$ and the lowest in the control at $1.32{\mu}g\;GAE/mg$. The content of flavonoids was the highest in TF100 at $3.66{\mu}g\;QE/mg$ and the lowest in controls at $0.45{\mu}g\;QE/mg$. The value of DPPH $IC_{50}$ was the highest in the control at $3,723.00{\mu}g/mL$ and the lowest in TF 100 at $405.27{\mu}g/mL$. The value of ABTS $IC_{50}$ was the highest in the control at $1,822.32{\mu}g/mL$ and the lowest in TF100 at $529.30{\mu}g/mL$. In sensory evaluation, while control, TF75, and TF100 had a higher score in appearance at 5.52~5.60, all samples had no significant differences in flavor, sweetness, savory taste, chewiness, and overall acceptability (p<0.05). These results showed that the gluten-free cookies containing teff flour can improve the quality characteristics and antioxidant activities of a cookie. We concluded that gluten-free cookies containing 100% teff flour are desirable.

• Journal of Chest Surgery
• /
• v.25 no.6
• /
• pp.581-587
• /
• 1992

Tracheoesophageal fistula[TEF] is a rare but life-threatening lesion that may occur from ventilation with a cuffed tube. It occurs most frequently when an inlying esophageal tube is also being used-usually for feeding purposes. The mechanism of injury appears to be pressure experted on the tracheal wall by the cuff, which then compresses the "party wall" of the trachea and esophagus against the foreign body that lies in the esophagus. The patient was 32 years old female who had been receiving a treatment of respiratory failure induced by postoperative sepsis with assist ventilator and nasogastric tubal feeding. Sudden attack of abdominal gas distention and massive drainage of gas through N-G tube were developed during assist ventilation in that patient, so we diagnosed as tracheal stenosis with a tracheoesophageal fistula induced by prolonged endotracheal intubation We performed tracheal reconstruction and primary closure of perforated esophagus after weaning ventilator. The postoperative course was uneventiful.eventiful.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.57 no.7
• /
• pp.1123-1128
• /
• 2008

The necessity of online dynamic security assessment is getting apparent under Electricity Market environments, as operation of power system is exposed to more various operating conditions. For on-line dynamic security assessment, fast transient stability analysis tool is required for contingency selection. The TEF(Transient Energy Function) method is a good candidate for this purpose. The clustering of critical generators is crucial for the precise and fast calculation of energy margin. In this paper, we propose a new method for fast decision of mode of instability by using stability indices and energy margin. The method is a new version of our previous paper.[1] Case studies are showing very promising results.

• Mycobiology
• /
• v.48 no.4
• /
• pp.245-251
• /
• 2020

During a survey of putative fungal pathogens infecting oak trees in the Gangwon Province of the Republic of Korea, a fungus resembling a Ceratocystis sp. was repeatedly isolated from natural wounds on Quercus variabilis. Morphological comparisons and DNA sequence comparisons based on partial β-tubulin and TEF-1α gene regions showed that the fungus resided in a distinct lineage. This novel Ceratocystis species is described here as C. quercicola sp. nov. This is the first novel species of Ceratocystis to be reported from Korea. A pathogenicity test showed that it can cause lesions on inoculated trees but that it had a very low level of aggressiveness. The discovery of this fungus suggests that additional taxa residing in Ceratocystis are likely to be discovered in Korea in the future.

• Proceedings of the Korean Society of Toxicology Conference
• /
• 2003.10b
• /
• pp.196-196
• /
• 2003

Food is a significant source of polycyclic aromatic hydrocarbons (PAHs) to which humans are exposed. In this study, we are analysed 14 PAHs in baked and smoked meats known as major source of PAHs, and defined a correlation between benzo(a)pyrene and pyrene to compare estimating risk from human exposure to PAHs with urinary1-hydroxypyrene.(omitted)

• Mycobiology
• /
• v.49 no.3
• /
• pp.267-274
• /
• 2021

Two Diaporthe species isolated from fruit of Citrus sinensis in China were characterized based on morphology and multilocus phylogeny of ITS, tef1, and tub2 gene sequences. The phylogeny indicated that the two species match Diaporthe taoicola and D. siamensis. A critical examination of phenotypic characteristics confirmed the phylogenetic results. Diaporthe taoicola was morphologically characterized by producing Alpha conidia with tapering toward both ends. Meanwhile, D. siamensis produced cylindrical or ellipsoidal Alpha conidia with two oil drops. Pathogenicity tests revealed that both species were pathogenic to fruit of C. sinensis. To our knowledge, the two species were firstly reported on Citrus sinensis in China.

• Mycobiology
• /
• v.49 no.6
• /
• pp.527-533
• /
• 2021

The truffle and ectomycorrhizal roots formed by Tuber sp. were collected from the rhizosphere of Quercus aliena in Korea. The morphological characteristics of the ascoma, and molecular phylogenetic analysis using sequences from the internal transcribed spacer (ITS) and large subunit (LSU) of ribosomal DNA, translation elongation factor 1-alpha (TEF), and RNA polymerase second largest subunit (RPB2) regions confirmed the distinct morphology of the truffle. This truffle belongs to a monophyletic clade among the other Tuber species in the phylogeny. This study describes the truffle, Tuber koreanum, as a new species reported from Korea.