• The Plant Pathology Journal
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• v.21 no.4
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• pp.317-321
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• 2005

Since 2000 severe rots on aerial and underground parts of paprika (Capsicum annum L.) has occurred in most surveyed glasshouses throughout the country. A total of 56 isolates of a fungus were consistently isolated from various plant parts such as fruit, stem, branch, and root collected from 16 farms in five provinces. Anamorph stage of the fungus was identified as Fusarium solani based on its morphological characteristics. However, the fungus readily produced a sexual structure of perithecia on infected plant tissues and on agar media. Since the fungus formed abundant perithecium by a single isolate, it was considered as a homothallic strain of Nectria haematococca, the teleomorph of F. solani. Irregularly globose perithecia with orange to red color formed sparsely to gregariously on dead tissues of fruits and basal stems at the late infection stage, which is a diagnostic sign for the disease. Perithecia ranged from 125 to 220 ${\mu}m$ in diameter varied among isolates. Asci enveloping eight ascospores were cylindrical and measured 60-80x8-12 ${\mu}m$. Ellipsoid to obovate ascospores are two-celled and measured 11-18x4-7 ${\mu}m$. Ascospores were hyaline, slightly constricted at the central septum, and revealed longitudinal striations that is characteristic of the species. This fungus that has never been reported in Korea has previously become a threat to paprika cultivation because of its strong pathogenicity and nationwide distribution.

• Research in Plant Disease
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• v.9 no.3
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• pp.153-158
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• 2003

Mycological characteristics of Phomopsis citri isolates obtained from blighted twigs of citrus cultivation areas in Jeju island were all identified as Phomopsis citri known as the anamorph stage of Diaporthe citri. Pycnidia the isolates sized from 112.2 to 614.4${\mu}m$ (av. 328.8${\mu}m$) and shaped conical to lenticulata in black. Two types of phialospores, ${\alpha}$-and ${\beta}$-spores were observed from pycnidia. The ${\alpha}$-spores were hyaline, unicellula, fusiform to ellipsoidal and sized 4.7~8.7 1.9 ${\times}$ 3.5${\mu}m$ (av. 6.7 ${\times}$ 2.3 ${\mu}m$). The ${\beta}$-spores were hyaline, unicellula, filiform, curved and often strongly hooked and sized 13.2~27.1 ${\times}$ 0.8~1.6 ${\mu}m$ (av. 22.1 ${\times}$ 1.0 ${\mu}m$). All isolates grew well and produced abundant pycnidia and spore horns on PDA. In addition, all isolates showed strong pathogenicity to citrus fruit inducing melanose symptoms when artificially inoculated with the pycnidial spores.

• The Plant Pathology Journal
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• v.25 no.1
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• pp.86-90
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• 2009

In November 2008, typical powdery mildew symptoms were observed on leaves of Arabidopsis thaliana ecotype Col-0 plants in a growth room under controlled laboratory conditions at Korea University, Seoul. The disease was characterized by the appearance of white powder-like fungal growth on the surface of infected leaves. As the disease progressed, infected leaves exhibited chlorotic or necrotic brown lesions, and leaf distortion and senescence. Conidiophores of the causal fungus were hyaline, unbranched, 3-4 celled, cylindrical, and $80-115{\times}6-9{\mu}m$ in size. Singly produced conidia (pseudoidium type) were hyaline, oblong to cylindrical or oval in shape, and $26-55{\times}15-20{\mu}m$ in size with a length/width ratio of average 3, angular/rectangular wrinkling of outer wall and no distinct fibrosin bodies. Appressoria on the hyphae were multi-lobed. These structures are typical of the powdery mildew Oidium subgenus Pseudoidium, anamorph of the genus Erysiphe. The measurements of the fungal structures coincided with those of Erysiphe cruciferarum. The phylogenetic analysis using ITS rDNA sequences revealed that the causal fungus Erysiphe sp. KUS-F23994 is identical to E. cruciferarum. The isolated fungus incited powdery mildew symptoms on the inoculated Arabidopsis leaves, which proved Koch's postulates. Taken all data together, we first report the occurrence of powdery mildew disease of A. thaliana caused by Erysiphe cruciferarum in Korea.

• The Korean Journal of Mycology
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• v.24 no.4 s.79
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• pp.246-254
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• 1996

Since the mid of 1980's, cultivation area and production of Ganoderma lucidum have been increased annually in Korea. However, the presence of a fungal disease has become a major limiting factor in the cultivation of Ganoderma lucidum, causing a serious economic loss. The present study was carried out to isolate and identify the pathogenic fungus to Ganoderma lucidum. Several fungi isolated from the wood logs showing typical symptoms were tested whether they are pathogenic to Ganoderma lucidum or not by cross-pairing culture method, flask inoculation method, and wood log inoculation method. The pathogenic fungus produced ascomata. Mature ascomata was spherical, dark, thick-walled, $45{\sim}95\;{\mu}m$ diameter. Asci were thin-walled, evanescent when mature, disintegrate early. Ascospores were spherical, hyaline, glaborous, thick-walled, refractive, $3.6{\sim}4.3\;{\mu}m$ in size. Conidiophores soon became abundantly septate and broke up into arthrospores, which are cylindrical, $3{\sim}6\;{\mu}m$ long and $3{\sim}4\;{\mu}m$ wide. Based on the observations under dissecting microscope, light microscope and scanning electron microscope, teleomorph and anamorph of the pathogenic fungus were identified as Xylogone sphaerospora Von Arx & Nilsson and Sporendonema purpurascens (Bonordon) Mason & Hughes, respectively. X. sphaerospora is first reported as a pathogenic fungus of Ganoderma lucidum.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.243-248
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• 1999

To compare the morphological and cultural characteristics of Cordyceps militaris, forming conditions of artificial fruiting body production were investigated in this experiment. The stroma shapes of artificial fruiting body were confirmed to club and/or stick. However, both shapes were same color as a orange. Perithecia of stroma was semi-egg shape and was ranged from $30{\sim}90{\times}90{\sim}130\;{\mu}m$ and it's asci was narrowly cylindric. Ascospore of perithecia was belong to filiform and multiseptate. The conidia of C. militaris was centurally grown and shaped with globose, long clavate type, floccose, centrally raised during anamorph stage. When it was cultured between glass and PP bottle, production of artificial fruiting body, pinheading ratio and total yield were higher in PP bottle. The optimum illumination was 1,000 lx for the those production. The culture medium of barley, wheat and hulled rice showed higher artificial fruiting body compared to that of silkworm. Pinheading and yield of it's isolates was decreased at more than three subsequent transculture.

• The Korean Journal of Mycology
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• v.45 no.2
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• pp.91-101
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• 2017

Three species of powdery mildew (Erysiphales) on eggplant (Solanum melongena L.) have been listed in Korea, namely Erysiphe cichoracearum (now genus Golovinomyces), Leveillula taurica, and Sphaerotheca fusca (now genus Podosphaera; syn. Podosphaera xanthii). Since E. cichoracearum was recorded on eggplant for the first time in Korea in 1969, it has been regarded as a major powdery mildew agent on that plant. In 1998, the causal agent of powdery mildew on eggplant was recorded as L. taurica, then as S. fusca in 2002. During our extensive field surveys in Korea, we collected 22 samples of eggplant powdery mildews. Our microscopic observations and molecular sequence analyses showed that all of our samples belonged to the genus Podosphaera, in the absence of either E. cichoracearum or L. taurica, suggesting that P. xanthii is the dominant agent of powdery mildew disease on eggplants in Korea. As there have been no additional findings on L. taurica after the first report on the species, it seems to be a minor species that is rarely found in greenhouses. The presence of E. cichoracearum (syn. Golovinomyces cichoracearum s. lat.) on eggplants is questionable, as the morphological characteristics of E. cichoracearum in the original description of the Korean collection deviate from the morphological variations of this species. In addition, no herbarium material of E. cichoracearum remains. Consequently, it seems that P. xanthii is the main species of powdery mildew on eggplants, whereas L. taurica occurs rarely on eggplants, in Korea. This review provides the historical and recent taxonomy of eggplant powdery mildews in detail.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.79-88
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• 2004

Cordyceps pruinosa grows upon dead pupae of Lepidoptera and produces one or $3{\sim}4$ club-shaped stromata per host. The stromata have distinct club-shaped head and long stalk. The length of stromata varies from $1{\sim}3\;cm$. Apical head consists of densely crowded semi-immersed perithecia, which are $360{\sim}400\;{\times}\;180{\sim}200\;{\mu}m$ in size. Asci are $150\;{\mu}m$ in length and $2.8{\sim}3\;{\mu}m$ in diameter. Ascospores, which are $124{\sim}141\;{\mu}m$ in length, have thin thread-like structures in the middle with part-spores attached on both sides. Each ascospore does not separate into part-spores after dispersal, but each part-spore germinates and together develops a colony. The imperfect form produces phialides of $15{\sim}24\;{\times}\;2{\sim}3\;{\mu}m$ size, with spherical or spindle shaped conidia of $4{\sim}6\;{\times}\;1.8{\sim}2.4\;{\mu}m$ size, The anamorph was identified as Mariannaea elegans Samson. YMA and SDAY agar media with pH 7 was produced abundant mycelial growth with high density. Best mycelial growth was observed when dextrin was used as a carbon source. Lactose, saccharose and sucrose also produced high mycelial growth. Peptone, yeast extract and tryptone produced abundant mycelial growth, when used as nitrogen sources. Highest mycelial growth and density was observed when C/N ratio was 1 : 1 at the concentration of 12.5 g/l each. $KH_2PO_4$ was the best mineral source for mycelial growth. Highest mycelial dry wt. was produced in YM and SDAY broths. Optimum inoculum for 100 ml of liquid broth was 6 mycelial discs. Similarly, optimum liquid culture period was 7 days.

• The Korean Journal of Mycology
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• v.30 no.2
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• pp.86-94
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• 2002

Recently a serious outbreak of weed mould caused by a species of Hypocrea occurred in oyster mushroom (Pleurotus ostreatus) substrates in Korea. The disease was characterized by a rapid infestation of the oyster mushroom substrates by Hypocrea sp. and subsequent inhibition of fructification of the mushroom. In spite of it's serious losses to the oyster mushroom industry in Korea, etiology and ecology of the disease have not been studied. Morphological characteristics of the fungus were examined and molecular characteristics of the fungus were compared with those of the green moulds (Trichoderma spp.) isolated from oyster mushroom bed. Stromata formed superficially on suface of the substrates were pulvinate to effuse or irreguler, initially white but becoming yellowish brown, measuring $6.0{\sim}13.0{\times}3.0{\sim}11.0mm$. Perithecia were globose to subglobose, immersed in stroma, $223{\sim}263\;(Ave.239.9){\times}167.3{\sim}231\;(Ave.204.1){\mu}m$ in size. Asci were unitunicate, cylindrical, nonamyloid, $82.7{\sim}124.8\;(Ave.103.3){\times}4.1{\sim}5.1\;(Ave.4.9){\mu}m$ in size, 16 part-spored. Ascospores were bullet-shaped or somewhat oblong, hyaline, bicellular, roughened or warted, $5.4{\sim}7.4\;(Ave.6.5){\times}3.6{\sim}5.5\;(Ave.4.7){\mu}m$ in size. This fungus readily form the stroma on PDA. Mycelia on PDA nearly invisible and without cottony aerial mycelium. Optimum temperature for mycelial growth of this fungus was $25^{\circ}C$ on PDA and its growth rate was 15 mm per day. This species did not grow at below 10 and above $35^{\circ}C$. Phialides in culture enlarged in the middle and aggregated to penicillate type. They were very variable, shorted ampulliform and occasionally curved when matured, but cylinderical when young, measuring $11.9{\sim}24.3\;(Ave.\;14.7){\times}2.9{\sim}3.9\;(Ave.\;3.4){\mu}m$ when matured and $7.2{\sim}14.0\;(Ave.\;10.8){\times}2.8{\sim}4.9\;(Ave.\;3.5){\mu}m$ when young. Phialosopres were ovoid to ellipsoid, smooth, measuring $3.5{\sim}7.2\;(Ave.\;4.5){\times}2.6{\sim}3.3\;(Ave.\;2.9){\mu}m$. Nineteen isolates of Hypocrea sp. were analyzed on the basis of molecular characteristics and classified into phenotypic groups. On the basis of RAPD, URP-PCR, the fungus was confirm to monoclonal, and was classified as a different taxon from reported species of Hypocrea and Trichoderma and supposed to be a new species not previously reported in literature.

• The Korean Journal of Mycology
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• v.27 no.4 s.91
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• pp.256-273
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• 1999

Seventy two isolates of Cordyceps militaris collected from 11 sites in Korea, including two isolates from ATCC, were used to assess genetic variation within Cordyceps militaris. The anamorph stage and cultural characteristics of C. militaris were observed through microscope and investigated on PDA respectively. The anamorphs of C. militaris were identified to be Verticillium. Isolates of C. militaris showed different growth rates, morphology and color. Fifty six isolates of single ascospore and seventy two isolates of mass ascospore from C. militaris were analysed using by Random Amplified Polymorphic DNA (RAPD) for genetic relationship analysis. Fifty six single ascospore isolates fell into two groups by phenogram constructed from distance values using the UPGMA method in NTSYS-pc software: group A from artificial fruit body of C18 except for isolate 51; group B from artificial fruit body of C738. The average genetic distance value within group A is 0.150 and group B is 0.163. The average genetic distance value between the two groups is 0.221. The average genetic distance value within 56 single ascospores is 0.207 and 72 mass ascospores is 0.330. Genetic relationships were not found among 72 mass ascospore isolates obtained from eleven geographically distant populations.