• The Plant Pathology Journal
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• v.17 no.6
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• pp.342-346
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• 2001

The physiological changes in sorghum (Sorghum vulgare Pers.) leaves infected with Drechslera sorghicola were investigated through five recognizable stages of disease development. Water-soaked yellowish brown spots developed two days after inoculation, turned brown with yellow halo, enlarged and coalesced at later stages of disease development. Healthy and infected leaves were analyzed for different biochemical constituents. The chlorophyll contents were decreased significantly with the progress of infection. The levels of reducing and total sugars increased while non-reducing sugars decreased to a significant extent with the progress of disease. The concentration of total phenolics, orthodihydroxy phenols, free and glycosidic phenols showed significant changes due to infection, whereas basic and acid phenols showed little or no change with disease development. Levels of phenolic compounds increased four days after inoculation and decrease thereafter, but the concentration was higher at every stage of disease development relative to healthy tissues. Polyphenol oxidase and peroxidase enzyme activities increased to varying degrees at different stages of infection. Analysis of protein fractions showed a significant increase with the progress of disease.

• The Plant Pathology Journal
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• v.17 no.6
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• pp.350-353
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• 2001

In 2001, a black scab disease was observed in tea plant (Thea sinensis) cultivated in the hillsides of Hwngaemyon and Hadong-gun, Gyeongnam province, Korea. The disease symptoms initially appeared on leaves, green twigs and stems, showing small dark brown spots on the infected areas, which gradually expanded. A fungus was isolated from diseased leaves and green twigs. It grew readily on potato dextrose agar, forming dark green to dark gray colonies. The optimum temperature for mycelial growth was about 20$^{\circ}C$. The diameter of growing hyphae was 3.5-5.8 $\mu\textrm{m}$. Conidia were ellipsoidal, ovoid or subspherical, and mostly one-celled but occasionally septate. The size of one-celled and septate conidia were 3.7-12.4${\times}$3.4-5.2 $\mu\textrm{m}$ and 9.3-18.7${\times}$3.8-7.2 $\mu\textrm{m}$, respectively. Conidia were formed in long branched chains on the erected conidiophores, which were dark brown in color and 28.9-218.3${\times}$3.0-6.1 $\mu\textrm{m}$ in length. The fungus was identified as Cladosporium herbarum on the basis of its morphological characteristics. The black scab disease occurring in tea caused by Cladosporium herbarum has not been previously reported in Korea.

• Research in Plant Disease
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• v.16 no.3
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• pp.323-325
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• 2010

The stem rot of sunflower (Helianthus annuus) occurred sporadically in the experimental field of Gyeongsangnam-do Agricultural Research and Extension Services, on September, 2009. The infected plants were wilted and water-soaked brown spots were formed on the stem, than infected stems were mostly died. White mycelial mats were spread over lesions, and then sclerotia were formed on stem and near soil line. The sclerotia were globoid in shape, 1~3 mm in size and white to brown in color. The optimum temperature for mycelial growth and sclerotia formation on PDA was $30^{\circ}C$ and the hyphal width was $4{\sim}8\;{\mu}m$. The typical clamp connections were observed in the hyphae of the pathogenic fungus. On the basis of mycological characteristics and pathogenicity to host plants, this fungus was identified as Sclerotium rolfsii. This is the first report on the stem rot of sunflower by S. rolfsii in Korea.

• Korean Journal of Ichthyology
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• v.1 no.1_2
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• pp.19-23
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• 1989

A puffer fish Fugu flavidus Li, Wang et Wang of Family Tetraodontidae was studied for the first time in Korea. Specimens were obtained from fish markets in Kunsan and Mokpo in February 1985 and June 1989. The Fugu flavidus is similar to F. obscurus and F. niphobles in morphometric characters, but differs from them in dorsal part of the body : yellowish-brown or greenish-brown, and covered with many round white spots which are clear in young and become indistinct as the fish grow. A new Korean name "Hwangjombok" is proposed for the F. flavidus.

• Korean Journal of Metals and Materials
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• v.50 no.1
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• pp.23-27
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• 2012

The color of a natural diamond that contains nitrogen impurities can be enhanced by a high pressure high temperature (HPHT) treatment. Type IaAB diamond samples containing nitrogen impurities were executed by HPHT process of 5.6 Gpa, 10 min by varying the annealing temperature at 1600, 1650, and $1700^{\circ}C$. Property characterization was carried out using an optical microscope, FT-IR spectrometer, low-temperature PL spectrometer, and micro Raman spectrometer. By observing optical micrographs, it can be seen that diamond sample began to alter its color to vivid yellow at $1700^{\circ}C$. In the FT-IR spectrum, there were no Type changes of the diamond samples. However, amber centers leading to brown colors lessened after $1700^{\circ}C$ annealing. In the PL spectrum, all the H4 centers became extinct, while there were no changes of yellow color center H3 before or after treatment. In the Raman spectrum, no graphite spots were detected. Consequently, diamond color enhancement can be done by higher than $1700^{\circ}C$ HPHT annealing at 5.6 GPa-10 min.

• Mycobiology
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• v.48 no.6
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• pp.495-500
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• 2020

Leaf spot on lemon balm is frequently observed in Korea, causing considerable damage to crops. In 2014 and 2015, the occurrence of leaf spot was observed in several production greenhouses at Suwon, Gongju, and Namwon in Korea. Symptoms on lower leaves initially developed as small, distinct, discolored lesions, which enlarged progressively turning into dark brown, angular spots surrounded by purplish-brown margins. Based on the morphological characteristics and sequence analysis of actin (ACT), translation elongation factor 1-alpha (EF-1α), internal transcribed spacer (ITS), 28S nrDNA (LSU), and RNA polymerase II second largest subunit (RPB2), the fungus associated with the lemon balm leaf spot was determined as Septoria melissae. To the best of our knowledge, this is the first report of lemon balm leaf spot caused by S. melissae in Asia as well as in Korea.

• Research in Plant Disease
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• v.30 no.1
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• pp.82-87
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• 2024

Leatherleaf fern (Rumohra adiantiformis) is an important ornamental plant in Indonesia and global. Green fern leaves with bold dark green color with long shelf-life, attract florists as decoration. Indonesia is one important leatherleaf fern exporters, however currently an outbreak of leaf blight decreased production significantly. Initial symptom was reddish brown spots from edge of leaf, which was gradually followed by dark-brown necrotic lesions causing leaf blight and dried. This is a study to do Koch-Postulate approach and molecular identification, to identify the pathogen of the "new emerging disease" reported. Based on multigene analysis using primers from ITS, β-tub and tef1-α gene markers, the pathogen was identified as Neopestalotiopsis sp. All sequences have been deposited in GenBank with accession number of OR905551 (ITS), OR899817 (ßtubulin) and OR899816 (TEF). This Neopestalotiopsis leaf blight causes an emerging concern in leatherleaf fern in Indonesia and global biosecurity because it infected an export commodity.

• Research in Plant Disease
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• v.9 no.3
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• pp.128-130
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• 2003

Rust diseases were found on safflower (Carthamus thinctorius) fields located in Euisong-gun Gyengbuk province in Korea. The infection rate of the disease in surveyed area was about 15% in 2001. The typical symptoms of the disease appeared first as small white spots on the leaf and turn brownish, dark brown spores revealed on them. Uredospores were light brown in color, ellipsoid or spherical in shape and 21~23 ${\times}$ 21~25${\mu}m$ in size. Teliospores were chestnut-brown in color, ellipsoid or ovoid in shape and 35~40 ${\times}$ 27~33${\mu}m$ in size. Pedicels were non-color of limpidness in color and 15~30${\mu}m$ in size. The causal fungus was identified as Puccinia carthami, based on morphological charateristics. This is first report on the rust of safflower caused by Puccinia carthami in Korea.

• The Korean Journal of Mycology
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• v.32 no.1
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• pp.54-56
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• 2004

Rust disease was occurred on blackberry lily (Belamcanda chinensis) in several farmer's fields located in Heohwa-myon, Goseong-gun, Gyeongnam province in Korea. The typical symptoms of the disease appeared as small, yellowish spot on leaves at first. The spots then turned brown, their edges rised slightly, and powdery mass of yellow or yellowish green spores appeared on the lesions. Severely infected leaves were blighted and eventually died. Urediniospores were yellow or yellowish brown in color, globoid to ovoid in shape and $21{\sim}46{\times}18{\sim}38\;{\mu}m$ in size. Teliospores were brown in color, oblong or clavate in shape and $32{\sim}64{\times}12{\sim}26\;{\mu}m$ in size. The causal fungus was identified as Puccinia belamcandae based on morphological characteristics and host specificity. This is the first report on the rust of B. chinensis caused by P. belamcandae in Korea.

• Korean journal of applied entomology
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• v.42 no.4
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• pp.361-365
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• 2003

Several species of planthoppers such as brown planthopper, N. lugens (Stal) (BPH), smaller brown planthopper, Laodelphax striatellus (Fall n) (SBPH), and white-backed planthopper, Sogatella furcifera (Horv th) (WBPH) are distributed in Korean rice paddies but not easy to discriminate them in situ. Accurate discrimination of them is an indispensable process in the forecasting for their outbreak and control. Especially, innovative discrimination method for BPH was required because BPH was one of the most important insect pest of rice. Nymphs and adults of BPHs, SBPHS, and WBPHS, thus, were examined their morphological characteristics in the paddies and laboratory. The nymphs of BPH had different characters from those of SBPH and WBPH. The nymphs of BPH had white fluorescent spot between bottom of compound eye and antenna, while there was no that spot the other two species. The white spot was the brightest at the nymphs just after hatching and getting weaker as the nymph developed. At last the white spot was totally disappeared at the adult stage. This white spot was innovative criterium to discriminate nymphs of BPH, SBPH, and WBPH in rice paddies.