• Research in Plant Disease
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• v.12 no.1
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• pp.55-57
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• 2006

Stem rot of Houttuynia cordata occurred in the experiment field of Research Institute of Natural Product, Uiseong, Gyeongbuk, Korea in July 2003. The typical symptoms of the disease were water-soaking, stem rot, necrotic tuber. White mycelial mats were spread over lesions and sclerotia were formed on died plant and near soil line. The sclerotia were spherical and irregular, 1-2.5 mm on potato dextrose agar (PDA), white to brown in color, The optimal temperature for hyphal growth was $28{\sim}30^{\circ}C$ and the hyphal diameter was $3{\sim}9{\mu}m$. Clamp connections were observed on PDA. Pathogenicity of the casual organism was provided on H. cordata according to Koch's postulate. The fungus was identified as Sclerotium rolfsii Saccardo on the basis of mycological characteristics and pathogenicity test to host plants. This is the first report on the stem rot of H. cordata caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.13 no.2
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• pp.119-121
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• 2007

Anthracnose of Salvia plebeia caused by Colletotrichum acutatum was observed in the exhibition field of Hamyang-gun, Gyeongsangnam-do Agricultural Research and Extension Services, in Korea. The disease mainly occurred on the leaves, petioles and stems of whole plant. The typical symptoms were water-soaked lesions on stems and petioles, rotted stems and withering then eventually died. The color of colonies of the pathogenic fungus grown on potato dextrose agar was pinkish gray. Conidia were fusiform in shape and was $8{\sim}17{\times}3{\sim}4\;{\mu}m$ in size. Appressoria were pale to dark brown in color, clavate in shape and the sizes were $8{\sim}11{\times}4{\sim}6\;{\mu}m$. Optimum temperature for mycelial growth was $25^{\circ}C$. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Colletotrichum acutatum J. H. Simmonds. This is the first report on the anthracnose of S. plebeia caused by C. acutatum in Korea.

• Research in Plant Disease
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• v.13 no.2
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• pp.126-129
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• 2007

Sooty leaf blight disease of Cymbium spp. was observed on orchid fields located at Gyeonggi-do in 2005-2006. Symptoms of the disease appeared on leaves and leaf spots were circular to nearly-circular, these circular blemished were yellow, with greater amounts of brown to black flecks forming as the spots enlarge. Severely infected leaves were dry and defoliated. These symptoms were realized wrongly as symptoms by virus. But Pseudocercospora cymbidiicola were isolated from the diseased plants. Conidiophores were produced on the lesion surface of the leaf with the blemished areas andconidia formed dark brown, cylindrical and straight to slightly curved, 5-9 septate, $23.7-85.0\;{\times}\;2.0-3.4\;{\mu}m$. Mycelial growth was mostly slow on potato dextrose agar and the optimum temperature for growth was $25^{\circ}C$. We were identified as Pseudocercoepora cymbidiicola based on the morphological characteristics.

• The Korean Journal of Mycology
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• v.33 no.1
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• pp.35-37
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• 2005

Anthracnose symptoms on Spiraea prunifolia were observed around the residential area of Dongbumyon, Geoje City, Gyeongnam Province, Korea in 2002 and 2003. Typical symptoms of the disease were dark red spot on the leaves and black spot on the stem. The pathogen formed gray to dark gray colony on potato dextrose agar. Conidia were single celled, color, ovoid or oblong in shape and $6{\sim}12\;{\times}\;3{\sim}5\;{\mu}m$ in size. Seta were dark brown in color, cone-shaped in shape and $23{\sim}42\;{\times}\;2{\sim}4\;{\mu}m$ in size. The optimum temperature for growth of the isolate was about $25{\sim}30^{\circ}C$. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Colletotrichum gloeosporioides. This is the first report on the anthracnose of S. prunifolia caused by C. gloeosporioides in Korea.

• Research in Plant Disease
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• v.18 no.2
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• pp.139-141
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• 2012

Stem rot symptoms of common bean occurred sporadically in Jinju, Korea. The typical symptom included water-soaking on the main stem, rotting, wilting, and blighting, which eventually leads to death of the plant. The sclerotia, white to brown, spherical with size of 1-3 mm, formed over lesions and surface soil line. The optimum temperature for mycelial growth and sclerotia formation was $30^{\circ}C$ on potato dextrose agar (PDA). The typical clamp connections were observed in the hyphae of the fungus grown on PDA. Mycological characteristics and pathogenicity to host plants indicated that the fungus was Sclerotium rolfsii Saccardo. This is the first report of stem rot on common bean caused by S. rolfsii in Korea.

• Research in Plant Disease
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• v.14 no.1
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• pp.61-63
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• 2008

Anthracnose of blueberry (Vaccinium spp.) caused by Colletotrichum gloeosporioides was observed in the exhibition orchard of Gyeongsangnam-do Agricultural Research and Extension Services in Korea, 2007. The typical symptoms were initially water-soaked lesions and then rotten on fruits, the infected fruits were dropped but some of them were hunged and mummified. The pathogenic fungus grown on potato dextrose agar showed greyish to dark gray color. Conidia were straight, cylindrical apex obtuse in shape and $10{\sim}20{\times}3{\sim}5\;{\mu}m$ in size. Appressoria were brown in color, clavate or ovate in shape and $6{\sim}18{\times}4{\sim}12\;{\mu}m$ in size. Optimum temperature for mycelial growth was $25{\sim}30^{\circ}C$. On the basis of mycological characteristics and pathogenicity test on host plants, the fungus was identified as Colletotrichum gloeosporioides (Penz.) Penz. & Sacc.. This is the first report on the anthracnose of blueberry (Vaccinium spp.) caused by C. gloeosporioides in Korea.

• The Plant Pathology Journal
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• v.15 no.2
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• pp.112-118
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• 1999

Eleven species of Pythium were isolated from leaf blight symptoms on creeping bentgrass (Agrostis palustirs Huds.), Kentucky bluegrass (Poa pratenisis L.) and zoysiagrasses (Zoysia japonica Steud., and Z. matrella (L.) Merr.) planted on golf courses in Korea. Mycelial growth on potato carrot agar medium under various temperature conditions indicated that Pythium species obtained in this study could be divided into four groups based on their responses to temperature conditions. P. vanterpoolii was found to favor low temperature conditions with the optimum temperature of $25^{\circ}$, whereas P. aphanidermatum and P. myriotylum favored relatively high temperature conditions with the optimum temperature of $35^{\circ}$. Other species including P. arrhenomanes, P. catenulatum, P. graminicola, P. oligandrum, P. rostratum, P. torulosum, and P. ultimum were the intermediate group with the optimum temperature of 25~$35^{\circ}$. P. periplocum was similar to the intermediate group but the minimum temperature for its mycelial growth was $15^{\circ}$, which was approximately $5^{\circ}$ above that for the intermediate Pythium spp.group. In the pathogenicity tests conducted in the lab using potted plants, P. aphanidermatum, P.a arrhenomanes, P. catenulatum, P. graminicola, P. myriotylum, P. periplocum, P. rostratum, P. torulosum, P. ultimum, and P. vanterpoolii were found to be pathogenic to creeping bentgrass and Kentucky bluegrass. P. aphanidermatum, P. catenulatum, and P. graminicola were frequently isolated from leaf blight symptoms of creeping bentgrass and Kentucky bluegrass in golf courses during the warm and humid periods in July-August. On the other hand, P. vanterpoolii and P. torulosum were frequently isolated during the cool and humid periods in March-May, suggesting both species might be the major causes of leaf blight occurring in the spring time. Zoysiagrass was susceptible to P. arrhenomanes and the heterothallic Pythium sp. (Ht-F), showing stem and crown rot of turf-grasses at poorly drained areas under coool and humid or rainy conditions. P. oligandrum and the heterothallic Pythium sp. (Ht-L) isolated from creeping bentgrass were avirulent to all species of turfgrasses tested in this study.

• Research in Plant Disease
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• v.27 no.3
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• pp.115-119
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• 2021

Sclerotinia rot was occurred on the leaf and stem of Peucedanum japonicum Thunb. in greenhouse field of Pohang city of Gyeongbuk province in Korea. The typical symptom of the disease was light brown spot and tipburn on infected leaves. The colony of the isolated fungus was white to light gray in color. Asci were cylindrical shape and 75-240×5.9-17.3 ㎛ in size. Apothecia were cup-shaped with numerous asci and 0.5-0.9 cm in size. Ascospores were aseptate and ellipsoid in shape, and 8.4-10.7×4.8-5.8 ㎛ in size. Sclerotia formed on the plants and potato dextrose agar medium were globose to irregular in shape and black in color. Partial sequencing of rDNA of this isolate showed that it was 100% consistent with that of Sclerotinia sclerotiorum. It was confirmed that the same lesion was formed by reinoculating this pathogen on a healthy P. japonicum Thunb. and the same strain was isolated. This is the first report on the Sclerotinia rot of P. japonicum Thunb. caused by S. sclerotiorum in Korea.

• The Korean Journal of Mycology
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• v.51 no.1
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• pp.51-56
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• 2023

Dendropanax trifidus belonging to the family Araliaceae, is a warm-temperate evergreen tree distributed in Jeju Island, Bogil Island, Geomun Island, Geoje Island, Wando, and Haenam in Korea. In June 2021, a root rot disease in which branches of Dendropanax trifidus seedlings turned brown and shrunk was discovered at the seedling cultivation facility in Naju-si, Republic of Korea. To identify the root rot fungus, three strains were isolated from the diseased tissues of seedlings and their mycological characteristics were investigated on potato dextrose agar. In addition, a molecular phylogenetic analysis was performed using sequences of the internal transcribed spacer (ITS) region and translation elongation factor 1-α (EF1-α) gene. The fungus was identified as Fusarium oxysporum. For pathogenicity test, the roots of seedlings were immersed in the conidia suspension of the strains and planted. After 20 days inoculation, root rot and browning symptoms were confirmed in the inoculated plants. This is the first report of F. oxysporum on D. trifidus in Korea.

• Journal of Species Research
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• v.12 no.spc2
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• pp.7-14
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• 2023

Several genera belonging to the family Acetobacteraceae were generally considered to be acetic acid bacteria (AAB) which produce acetic acid from alcohols using an oxidation pathway. Some species of the family Acetobacteraceae have been of interest to the industry due to their capability to produce vinegar. In 2018-2020, several bacterial strains were isolated from plants, fruits and vinegar in various regions of the Republic of Korea. Based on the 16S rRNA gene sequences, seven species classified into the family Acetobacteraceae were found to be ones unrecorded in the Republic of Korea, including two Asaia species, one Gluconacetobacter species, three Gluconobacter species and one Komagataeibacter species. As a result, we report Asaia lannensis AF11C3 (=KACC 22050) isolated from plant Chrysanthemum zawadskii, Asaia platycodi AF15C2 (=KACC 22051) isolated from plant Isodon inflexus, Gluconacetobacter liquefaciens C23-3 (=KACC 22064) isolated from fruit of Pyrus pyrifolia, Gluconobacter cerinus BGF2-R2 (=KACC 22053) isolated from fruit of Prunus armeniaca, Gluconobacter kondonii FR39A4 (=KACC 22388) isolated from persimmon fruit, Gluconobacter thailandicus FR36C4 (=KACC 22057) isolated from fruit of Pseudocydonia sinensis and Komagataeibacter melaceti SPV-2 (=KACC 22058) isolated from potato vinegar.