• Mycobiology
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• v.33 no.2
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• pp.69-76
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• 2005

Conidial development of Cordyceps militaris was observed from germinating ascospores and vegetative hyphae through light and scanning electron microscopy (SEM). Ascospores were discharged from fresh specimens of C. militaris in sterile water as well as Sabouraud Dextrose agar plus Yeast Extract (SDAY) plates. We observed ascospore germination and conidial formation periodically. Under submerged condition in sterile water, most part-spores germinated unidirectionally and conidia were developed directly from the tips of germinating hyphae of part-spores within 36 h after ascospore discharge, showing microcyclic conidiation. First-formed conidia were cylindrical or clavate followed by globose and ellipsoidal ones. Germination of ascospores and conidial development were observed on SDAY agar by SEM. Slimy heads of conidia on variously arranged phialides, from solitary to whorl, developed 5 days after ascospore discharge. Besides, two distinct types of conidia, elongated pyriform or cylindrical and globose, were observed in the same slimy heads by SEM. Conidia were shown to be uninucleate with 4,6-diamidino-2-phenylindole staining. Conidiogenous cells were more slender than vegetative hyphae, having attenuated tips. Microcyclic conidiation, undifferentiated conidiogenous hyphae (phialides), polymorphic conidia and solitary, opposite to whorled type of phialidic arrangement are reported here as the characteristic features of asexual stage of C. militaris, which can be distinguished from other Cordyceps species.

• Journal of the Korean Wood Science and Technology
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• v.28 no.4
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• pp.10-16
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• 2000

Two wood decay ascomycetes fungi identified as Hypoxylon mammatum and H. truncatum were isolated from backyard of Korea Research Institute of Chemical Technology (KRICT) in Korea. Hypoxylon truncatum is newly recorded as a wood degrader in Korea. Unusual germination mechanisms of ascospores in H. mammatum and H. truncatum are described and illustrated. The differences between two species were noticed on the process of germ tube formation. In the process of germ tube formation, the fast movement to pigmented ascospores activated from their perispores was termed as spore eclosion that was only found in H. mammatum. This sophisticated recognition mechanism indicated the existence of specific eclosion and germ tube formation due to the composition of cell wall layers and their preferable host derive, based on examined two species under a genus. The observation on present study postulates different composition of wall layers of ascospore and different nutrient composition for germination.

• Mycobiology
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• v.44 no.4
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• pp.202-216
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• 2016

Arthonia coreana, Arthonia superpallens, and Arthonia zelkovae are new species from South Korea. All new species are in the Euarthonia tribe, based on the key characteristics of colorless hypothecium and multi-cellular spores. A. coreana has a dull brownish hypophloedal thallus without bleaching and rounded or curved big apothecia in comparison with those of Arthonia punctiformis. A. coreana consistently exhibits 4-septate ascospores, which is a distinctive characteristic that distinguishes it from other Arthonia species. A. superpallens has a white-greenish thallus, pale yellowish apothecia, and a trentepohlioid alga. However, A. superpallens has no distinct prothallus, adnate, and convex apothecia, no pycnidia, and is UV-, in contrast with related species in the Arthonia antillarum group. A. zelkovae has a white, epiphloedal thallus, brownish-black epruinose apothecia covered with a whitish bark layer, and smaller ascospores in comparison with those of A. punctiformis. A. zelkovae consists of a chlorococcoid alga, which differs from related Arthonia species such as A. punctiformis, Arthonia pinastri, and Arthonia glaucella. Although A. zelkovae is similar to Arthonia dispersa in its white-colored thallus, blackish apothecia, and the presence of a chlorococcoid photobiont, A. zelkovae differs from the latter in having larger-sized 3-septate ascospores. Arthonia cinnabarina f. marginata, A. glaucella, Arthonia ilicinella, Arthonia lapidicola, Arthonia leioplacella, Arthonia pertabescens, A. pinastri, Arthonia spadicea, and Arthonia stellaris are newly described in Korea. The diagnostic characteristics of these species are discussed and presented. An artificial key is provided to facilitate identification of Arthonia species from Northeast Asia.

• Research in Plant Disease
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• v.10 no.4
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• pp.209-216
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• 2004

The circular leaf spot of persimmon is occurred almost every place where persimmon is cultivated, especially the disease outbreak severely in southern part of Korea. The disease reveals unusually long incubation period after pathogen invade into leaf tissue and no practical control measure is available once the symptom has appeared. Most of the farmers just follow the suggested spray schedules calculated on the basis of weather condition of ordinary years. Therefore the damages due to circular leaf spot greatly differ year after year. In this article, we tried to describe and summarized the investigation on the circular leaf spot pathogen, Mycosphaerella nawae, related to disease outbreak such as overwintering of pathogen, inoculum formation and spread, incubation period after infection, and secondary inoculum. With the summary of these results, we suggest the disease cycle of circular leaf spot of persimmon. The pathogen overwinters in diseased leaves as mycelial form or pseudoperithecial premodium. The pseudoperitheria become matured in spring as the temperature raise and forms asci and ascospores. The maturation of pseudoperithecia are closely related to the temperatures during March and early April. The ascospores completely mature in early May and the ascospores released when the pseudoperithecia absorbed enough moisture after rainfall. The release of ascospores are diverse greatly with the variation of maturity of pseudoperithecia. Generally the spore start to release from middle of May to early of July. Duration of ascospore release is depend on the weather condition of particular year, especially amount and number of precipitation. The ascospores produced from pseudoperithecia is known to the only inoculum for circular leaf spot disease. But according to the results obtained from our investigations, the conidia formed on the lesions which incited by natural infection. This conidia are infectious to persimmon leaves and formed identical symptom as natural infection. The time of producing secondary inoculum of circular leaf spot of persimmon is considered too late to develop new disease. Generally the importance of secondary inoculum is low but the conidia produced in early September are competent to develop new disease and new infection also significantly affect to harvest of persimmon. The importance of circular leaf spot disease is recognized well to farmers. The approaches to control of the disease should be initiated on the basis of the knowledges of inoculum dynamics and ecology of disease development. The forecasting system for circular leaf spot is need to be developed.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.87-93
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• 2016

From 182 non-pathogenic wild yeast isolates from flowers, Pichia silvicola UL6-1 and Sporobolomyces carnicolor 402-JB-1 were selected for potent ${\gamma}$-aminobutyric acid production and microbiological characteristics were investigated. Pichia silvicola UL6-1 formed ascospores and pseudomycelia. The strain was also halotolerant, growing well in 5% NaCl-containing yeast extract-peptone-dextrose (YPD) medium. Sporobolomyces carnicolor 402-JB-1 did not form ascospores or pseudomycelia and grew well on 10% glucose-yeast extract-peptone medium.

• The Korean Journal of Mycology
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• v.30 no.2
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• pp.170-172
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• 2002

An unrecorded Hypoxylon sp. was observed on the bed-log of oak-mushroom (Lentinula edodes) in Korea. The stroma of the fungus was formed on the bed-log (Quercus spp.) damaged by Korean squirrel (Sciurus vulgaris coreae). Perithecia were $200{\sim}400{\mu}m$, and asci containing 8 ascospores were $7{\sim}8{\times}150{\sim}230{\mu}m$ in size. Paraphysis was cylindrical shape, Ascospores were $5{\sim}9{\times}12{\sim}17.5{\mu}m$ in size, pale brown to dark brown, elliptical, and smooth. They have germination cleft and $1{\sim}2$ oil droplets.

• The Korean Journal of Mycology
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• v.27 no.5 s.92
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• pp.341-344
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• 1999

The genus Hypocrea, a member of the Hypocreales, has yellow to pale yellow-ochre, perithecial stromata and angular to cuboid ascospores. The isolate of Hypocrea microrufa collected on decayed tropical wood at Malaysia is compared with H. rufa and H. microsplendens. This isolation of H. microrufa will be the first record from tropical region and the first description with scanning electron microscopy. The ornamentation of ascospores used one of main taxonomic keys for identification.

• Applied Microscopy
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• v.34 no.4
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• pp.271-276
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• 2004

The genus of Biscogniauxia, well known wood degrading fungi, is a member of the Xylariales, which has woody to carbonaceous, brown to dark brown stromata. Daldinia concentrica and Biscogniauxia sp. isolated from heavily decayed hardwood, are precisely described under light microscopic and scanning electron microscopic level. Daldinia concentrica will be the first ultrastructural description in Korea. The unidentified species collected, having small size of ascospores $11.4\;15.6{\times}9.6\;12.0{\mu}m$ with full germ slit, are taxono-mically compared with similar species found in Korea.

• Applied Microscopy
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• v.37 no.4
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• pp.281-287
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• 2007

The genus Hypoxylon is a member of the Xylariaceae that has brown to dark brown and phaseoliform single cell ascospores with a conspicuous full germ slit. Hypoxylon truncatum differs from H. annulatum, it has conspicuous perithecial mounds, dark brown stromatal surface, and absence of enriched ostiola disc. The isolate of Hypoxylon, collected from Mt. Deuk-yu in Korea, is compared with similar taxa and described. The isolation of H. truncatum is compared with similar taxa, H. annulatum, with a precise description in the SEM level in Korea.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.294-296
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• 2000

Anthracnose symptoms were frequently found on stems of Indian fig cactus in Cheju island of Korea in 1998 and 1999. Typical symptoms were gray to black dry rot of stems with concentric arrays of dot-like spots. A Glomerella sp. or a Colletotrichum sp. was frequently isolated from the symptoms, both of which were identified as Glomerella cingulata and its anamorph, Colletotrichum gloeosporioides based on their morphological and cultural characteristics. Out of 31 isolates obtained from the symptoms, 12 isolates were the anamorph producing only conidia, four isolates the telemorph producing only ascospores, and 15 isolates the holomorph producing both spores on potato dextrose agar. Stem rots similar to the original anthracnose symptoms were induced by wound inoculation of conidia and ascospores but not by non-wound inoculation. The anamorphic isolates caused more extensive stem rot than the telemorphic and holomorphic ones.