• Biotechnology and Bioprocess Engineering:BBE
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• v.9 no.6
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• pp.440-446
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• 2004

Interest in in vitro study of entomopathogenic fungi, including Cordyceps species, has been increasing due to their valuable bioactive compounds and biocontrol effects. Among Cordyceps species, in vitro stromata of C militaris has been successfully produced and cultivated for industrial purposes. However, genetic study on in vitro stromata formation of C militaris has not been carried out yet. Here, relationship between mating system and perithecial stromata formation of C militaris is reported. Mating system was determined by observing perithecial stromata formation from mono-ascospore cultures and their pair-wise combinations. Certain combinations of mono-ascospore strains produced perithecial club-shaped stromata, whereas other combinations produced either no stromata or only abnormal non-perithecial stromata. Similarly, mono­ascospore cultures without combination produced either no stromata or only abnormal non­perithecial stromata. Despite obvious heterothallism, self-fertility was occasionally observed in few strains of C militaris. These observations indicated that C militaris behaves as a bipolar het­erothallic fungus and requires two mating compatible strains in order to produce regular club­shaped perithecial stromata, a fundamental requirement for its industrial cultivation.

• 한국균학회소식:학술대회논문집
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• 2009.10a
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• pp.76-95
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• 2009

In the fungal genus Cordyceps, the type species Cordyceps militaris produces bioactive ingredients and exhibits medicinal effects as a Traditional Chinese Medicine (TCM), The fruiting bodies of C.militaris have now been mass-produced artificially and used as functional food and medicine in China. The unstable variation in forming fruiting body is however a key restrictive factor in industrial production. The genetic study on in vitro stromata formation of C. militaris has rarely been carried out. Here, we report the effects of genetic variation including the mating system on perithecial stromata formation of C. militaris. Monoconidial isolates which have both MAT1-1-1 and MAT1-2-1(genotype MAT1-1/2) could produce stromata. While the isolates only have either MAT1-1-1 or MAT1-2-1 (genotype MAT1-1 or MAT1-2) failed to produce stromata. Despite obvious heterothallism, homothallism was occasionally observed in a few isolates of C. militaris. High genetic variation was observed amongst the different monoconidial isolates of C. militaris. The unstable variation or lose of fruiting body formation was found to be caused by the inner-species high genetic variation of C. militaris. These results also indicated that C. militaris sexually behaved as both heterothallic and homothallic and required two mating type compatible in the same culture in order to produce regular clubshaped perithecial stromata.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.152-158
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• 2003

Stromata of the white root rot fungus, Rosellinia necatrix, were produced on diseased roots although they were reported to develop rarely in nature. Forty-two (42) out of 47 samples produced synnemata while 23 developed stromata. Forty-seven (47) isolates obtained from diseased root samples were divided into 24 mycelium compatibility groups (MCGs). Sixteen (16) out of 24 MCGs produced stromata. Single ascospore isolates from 10 stroma samples produced dsRNA-containing isolates from diseased tissue beneath stromata. The frequency of synnema production on axenic culture varied among isolates with different origin. The dsRNA was not transmitted vertically to the ascospore offspring despite the infection of various dsRNA in the parental isolates. The dsRNA was absent in 35 ascospore isolates in two stroma samples that originated from the isolates, in which dsRNA was not eliminated by hyphal tip isolation. Consequently, sexual reproduction in the white root rot fungus was suggested to produce propagules as a new infection source and to have the function to eliminate infectious factors such as mycoviruses.

• Applied Microscopy
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• v.27 no.4
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• pp.453-460
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• 1997

The tissue types of stromata were observed intensively in four species of Hypoxylon under a scanning electron microscope (SEM). These stromata were sectioned with a freezing fracture method for observation. Several tissue types were recognized and stable in each species. This study presents the most intensive observation of tissue types of each layer of stromata. It will be useful for taxonomic criteria for the species level. However, the tissue types can not be major taxonomical criteria for the genus Hypoxylon.

• Mycobiology
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• v.38 no.2
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• pp.118-121
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• 2010

Single ascospore isolates of Cordyceps bassiana were observed for their colony pigmentation on Sabouraud Dextrose agar plus Yeast Extract (SDAY) plates and were inoculated in a brown rice medium for production of fruiting bodies. Colony pigmentation did not show any relationship with perithecial stromata formation. The isolates were also grown on opposite sides of SDAY agar plates and were observed for vegetative compatibility. Neither vegetative compatibility nor perithecial stromata could be found to be related to each other. It was concluded that fertile fruiting body production was independent of colony pigmentation and vegetative compatibility. Synnemata formation was found to be more common than perithecial stromata formation. This might be due to its highly conidiogenous anamorphic stage, i.e., Beauveria bassiana.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.266-274
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• 2001

The chemical properties and physiological activities of the freeze-dried stromata of Cordyceps militaris were examined. A proximate analysis exhibited that the stromata consisted mainly of crude carbohydrate (74.3%), crude protein (11.5%), and moisture content (8.7%), with a low content of crude ash (4.%) and fat (1.3%). The carbohydrate was mostly composed of glucose (88.6%). A large quantity of essential fatty acids, including linolenic acid (33.8%) was also observed. An analysis of the component amino acid showed a relatively high ratio of the essential amino acids, lysine (101.2 mg/g), methionine (62.7 mg/g), and acidic amino acids of glutamic aicd (57.5 mg/g) and aspartic acid (43.9 mg/g), whereas a low of tyrosine content (4.7 mg/g). An examination of the cordycepin content indicated tht the stromata and mycelium-embedded media (silkworm pupae) contained 0.2% and 0.5%, respectively. From the examination of the physiological activities, based on methanol extract (M), ethylacetate extract (EA), and hot-water extract (HW) fractions of the stromata, the hot-water extract (HW) fraction showed the most potent intestinal immune modulating activity, anticoagulant activity, and anticomplementary activity, whereas the ethylacetate extract (EA) fraction exhihited a radical scavenging activity. Therefore, the results from the present study indicate that the stromata of C. militaris contain various healthy chemical ingredients, and that especially boiled water extract of whole body would apprear to provide beneficial physiological activities.

• Mycobiology
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• v.38 no.1
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• pp.13-16
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• 2010

A specimen of Beauveria bassiana was collected from Yang-yang of Gangwon province, Korea in October 2006. Conidial isolates were prepared from the specimen by the dilution method and inoculated in brown rice medium for fruiting body production. After nearly two months incubation for perithecial stromata developed from single isolates as well as from their combinations. They were determined as Cordyceps bassiana by observing the stromatal characters and their conidial structures. This is the first report of the development of C. bassiana from B. bassiana cultures.

• The Korean Journal of Mycology
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• v.25 no.3 s.82
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• pp.161-166
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• 1997

Occurrence of Hypoxylon truncatum, known as a symbiont of white jelly mushroom, was first noted and described in Korea. Two stromatal forms reported in North American collections of H. truncatum sensu Miller were also observed in Korean collections. Based on evidences from other studies, polymorphic patterns seen in six enzyme digestions of nuclear Internal Transcribed Spacer (ITS) regions of Korean isolates indicated that the two stromatal forms were genetically distinct. Because there was a clear association of stromatal morphology with genetic differences, the different stromatal forms might be different species. In addition, clear species concept on the species H. truncatum would provide aids in selecting proper strain for cultivation of white jelly mushrooms.

• Mycobiology
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• v.38 no.4
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• pp.282-285
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• 2010

Cordyceps cardinalis successfully produced its fruiting bodies from multi-ascospore isolates. However, subcultures of multiascospore isolates could not produce fruiting bodies after few generations. Fruiting body production also differed from sector to sector of the same isolate. Single ascospore isolates were then co-inoculated in combinations of two to observe the fruiting characteristics. Combinations of certain isolates produced perithecial stromata formation, whereas other combinations did not produce any fruiting bodies. These results show that C. cardinalis is a heterothallic fungus, requiring two isolates of opposite mating types for fruiting body production. It was also shown that single ascospore isolates are hermaphrodites.

• Mycobiology
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• v.34 no.3
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• pp.131-137
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• 2006

In vitro fruiting bodies were produced from ten different isolates of Condyceps militaris EFCC C-5736, EFCC C-5941, EFCC C-5976, EFCC C-6040, EFCC C-6849, EFCC C-7268, EFCC C-7342, EFCC C-7992, EFCC C-8027 and EFCC C-8549. Single ascospores were isolated from in vitro grown fruiting bodies and used for fruiting body production in brown rice medium by both intra-strain crossing and out-crossing. Length and dry wt. of stromata grown in vitro were measured. Strains producing highest dry wt. of stromata were selected. Both intra-strain crossings and inter-strain crossings of single ascospore strains were found to produce profuse fruiting bodies of C. militaris.