• The Plant Pathology Journal
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• 제30권3호
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• pp.229-235
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• 2014

Pear skin stains on 'Niitaka' pears, which occur from the growing stage to the cold storage stage, reportedly negatively influence the marketing of pears. These stains on fruit skin are likely due to a pathogenic fungus that resides on the skin and is characterized by dark stains; however, the mycelium of this fungus does not penetrate into the sarcocarp and is only present on the cuticle layer of fruit skin. A pathogenic fungus was isolated from the skin lesions of infected fruits, and its pathogenicity was subsequently tested. According to the pathogenicity test, Mycosphaerella sp. was strongly pathogenic, while Penicillium spp. and Alternaria spp. showed modest pathogenicity. In this present study, we isolated the pathogenic fungus responsible for the symptoms of pears (i.e., dark brown-colored specks) and identified it as Mycosphaerella graminicola based on its morphological characteristics and the nucleotide sequence of the beta-tubulin gene. M. graminicola was pathogenic to the skin of 'Niitaka' pears, which are one of the most widely growing varieties of pears in South Korea.

• 한국균학회지
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• 제8권1호
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• pp.53-57
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• 1980

An undescribed black root rot of soybean, caused by Cylindrocladium crotalariae, was observed in Suweon area. The diseased plants showed yellowing at the top and dry rot at the root. Lesions of roots and stems in the soil were red to brown and main roots were cracked. Although not observed the disease in the field, leaves of inoculated test plants in the greenhouse exhibited circular, brown lesion surrounded by chloratic halos. The fungus was recovered in culture from the infected stem and root, and the perithecia of Calonectria crotalariae were demonstrated to be present as well as the cylindrocladium state. The fungus was pathogenic to the root, stem, petioles and leaves of soybean. The probable source of primary inoculum was microsclerotia formed in infected soybean root and stem from the previous season's soybean debris. Black root rot by this fungus was considered to be one of detrimental factors to the maximum yield of soybean. From the morphological and physiological characteristics and pathogenic behaviors, this fungus was identified as Cylindrocladium(Calonectria) crotalariae.

• The Plant Pathology Journal
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• 제19권2호
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• pp.75-78
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• 2003

A lichen-forming fungus was successfully isolated by discharged spore method from Korean lichen (Hetero-dermia sp.) and cultivated in pure culture. The isolate JR0012 inhibited mycelial growth of several plant-pathogenic fungi. Mycelial growth of the four Pythium spp. tested was completely inhibited. Potato dextrose broth was found to be the medium favorable for large-scale production of antibiotics from the isolate. Anti-fungal substances produced in axenic culture were partially purified. This is the first report in Korea of lichen-forming fungus successfully isolated and which exhibited strong antifungal activity against plant-pathogenic fungi, especially the four Pythium spp..

• 한국균학회지
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• 제24권4호통권79호
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• pp.246-254
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• 1996

1980년대 중반이후로 우리나라에서 영지의 재배면적과 생산량은 매년 증가해 오고 있지만 1980년대 말기부터 강화, 철원, 신탄지 등지에서 발생하기 시작한 새로운 병원성 진균의 출현에 의해서 영지재배는 막대한 경제적 손실을 입고 있으며 영지재배의 제한적 요인이 되고 있는 실정이다. 이 연구는 영지재배시에 발생하는 새로운 진균성 병해의 효과적인 방제수단을 찾기 위한 노력의 일환으로 병원성 진균을 분리하고 동정하기 위하여 실시되었다. 병원균에 의해 감염된 영지재배 원목에서 분리한 균주가 인공 접종시 전형적인 병징을 나타낼 수 있는지 병원성 검정을 실시하였고, 병원성 진균에 의해서 생성되는 병징, 균사, 분절포자, 자낭과, 자낭포자 등을 육안, 해부현미경, 광학현미경, 주사전자현미경 등을 사용하여 관찰하였다. 이 병원균에 의하여 형성되는 자낭과는 성숙시 검은색의 두꺼운 막으로 된 구형으로 직경은 $45{\sim}95\;{\mu}m$로 크기가 다양하였다. 자낭은 막이 얇고 형성되는 즉시 없어지기 때문에 매우 관찰하기 어려우며 자낭포자는 구형으로 무색이며 비교적 두꺼운 막으로 싸여 반들반들하게 보이고 크기는 $3.6{\sim}4.3\;{\mu}m$ 정도로 균일하였다. 분생자병은 즉시 막이 두꺼워지고 격막으로 나누어지면서 분절포자가 형성되었고 분절포자는 원통형으로 길이가 $3{\sim}6\;{\mu}m$족이 $3{\sim}4\;{\mu}m$정도였다. 따라서 이상의 형태학적인 특성에 기초하여 이 병원균의 완전세대는 Xylogone sphaerospora Van Arx & Nilsson로, 불완전세대는 Sporendonema purpurascens (Bonordon) Mason & Hughes로 동정되었으며, 이 균은 영지의 병원균으로는 처음 보고되는 것이다.

• The Plant Pathology Journal
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• 제34권5호
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• pp.367-380
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• 2018

Stems and pods of hyacinth bean cultivated in a farmer's field in Gazipur District, Bangladesh, were found rotted in nearly 5% hyacinth bean plants. A fungus having fluffy mycelium and large sclerotia was isolated from affected tissues. Combined results of morphological, molecular and pathological analyses identified the fungus as Sclerotinia sclerotiorum (Lib) de Bary. Inoculating the fungus on healthy hyacinth bean plants and pods reproduced the symptoms previously observed in the field. The three isolates obtained from naturally infected plants were cross inoculated in hyacinth bean, okra and African-American marigold and they were pathogenic to these hosts. The optimum temperature and pH for its growth were $20^{\circ}C$ and pH 5.0, respectively. Sclerotial development was favored at pH 5.0. Sucrose and mannitol were the best carbon sources to support hyphal growth, while glucose was the most favourable for sclerotial development. The hyacinth bean genotypes, HB-82 (Rupban Sheem) and HB-102 were found highly resistant, while HB-94 (Ashina) was moderate resistant to the fungus. Finally, S. sclerotiorum was sensitive to Bavistin, Dithane M-45 and Rovral fungicides and Ca in the form of $CaCl_2$. This observation could possibly aid in eliminating field loss in hyacinth bean caused by an emerging pathogenic fungus S. sclerotiorum.

• 한국어업기술학회:학술대회논문집
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• 한국어업기술학회 2002년도 추계 수산관련학회 공동학술대회발표요지집
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• pp.175-176
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• 2002

Rice blast, caused by Pyricularia oryzae (P. oryzae), is generally considered to be the most serious fungal disease of rice by its widespread distribution and destructiveness (Manandhar et al., 1998). The pathogenic fungus directly penetrates into the rice plant from a cellular structure called an appressorium that is formed at the tip of the germ tube. And the fungus can attack any aerial part of the rice plant, including seeds, in which the fungus may overwinter for several years. (omitted)

• KSBB Journal
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• 제31권4호
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• pp.312-314
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• 2016

This study was carried out to determine the antifungal activity of $SeO_2$ against pathogenic fungus, Candida albicans. Concentration-dependent Inhibitory activity of $SeO_2$ against C. albicans was shown. When $400{\mu}g/disc$ of $SeO_2$ was tested, the inhibition size ranged from 20.7 to 26.8 mm (avg. 23.4 mm). MIC values of $SeO_2$ against cell growth of C. albicans ranged from 50 to $100{\mu}g/mL$ (avg. $70{\mu}g/mL$). These results could be applied to antibiotics-resistant C. albicans and other pathogenic fungi.

• The Plant Pathology Journal
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• 제15권1호
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• pp.72-75
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• 1999

A scab disease occurred on watermelon seedlings by the infection of Cladosporium cucumberinum. This is the first report demonstrating the scab disease on watermelon in Korea. The casual agent attacked all plant parts of the seedlings on the ground. Infection sites were initiated with sunken and dark green spots, and then suddenly developed to large lesions softened with gummy substances. When hypocotyl and leaf stalk of seedlings were infected and softened, upper parts of seedlings were brokin down, dried and eventually died. Conidiophores of the fungus were characterized by pale olivaceous brown color, and variable length of about 3-5 mm in width. Conidia were formed I long branched chains, and conidium was ellipsoidal, fusiform or subspherical single cell mostly without septum. Morphological characteristics of the fungus were almost identical to Cladosporium cucumerinum Ellis & Authur. The fungus was also pathogenic to cucumber, squash and oriental melon, suggesting that it is a common pathogen to cucurbits. However, the fungus was not pathogenic to bottle gourd.

• Mycobiology
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• 제37권1호
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• pp.48-52
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• 2009

Essential oils are mixtures of volatile, lipophilic compounds originating from plants. Some essential oils have useful biological activities including antimicrobial, spasmolytic, antiplasmodial, and insect-repelling activities. In this study, we tested the antimicrobial activity of essential oil prepared from the aromatic plant, Cymbopogon citrates, against three important plant pathogenic and medical microorganisms, Pectobacterium carotovorum, Colletotrichum gloeosporioides, and Aspergillus niger. It effectively inhibited the growth of the bacterium, Pectobacterium carotovorum, in a dose-dependent fashion, and 0.5% of the oil inhibited the growth of bacteria completely. Similarly, the essential oil inhibited the growth of plant pathogenic fungus, Colletotrichum gloeosporioides, and the addition of 1% of essential oil completely inhibited the growth of fungus even after 5 days of culture. Finally, it effectively inhibited the growth of the medically and industrially important fungal species, Aspergillus spp. These results suggest that the essential oil from Cymbopogon citrates may be an environmentally safe alternative to inhibit antimicrobial agents for various uses.

• 한국미생물생명공학회:학술대회논문집
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• 한국미생물생명공학회 2003년도 2003 Annual Meeting, BioExhibition and International Symposium
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• pp.154-154
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• 2003