• The Korean Journal of Mycology
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• v.24 no.3 s.78
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• pp.186-205
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• 1996

This study was carried out to obtain data concerning the genetic variability of Pleurotus ostreatus. Monospores of P. ostreatus were isolated and cultured to estimate differences in the rate of mycelial growth and genetic similarity among the isolates. Although the overall growth rates were slow compared to their parental dikaryon except 2-MI 4, significant differences in the rate of mycelial growth were observed among isolates. Random amplified polymorphic DNA (RAPD) analysis using twenty six random primers showed 345 polymorphic DNA bands from 35 monospore isolates and their parental dikaryon. DNA bands ranged from 0.1 to 4.0 Kb in size. Most various polymorphic DNA bands within monospore isolates were obtained when we used J (OPA-01) or W (OPB-04). The 36-MI 103 showed totally different band patterns from those of the others. RAPD analysis revealed that there is approximatly 75% genetic similarity between monospore isolates and their parental dikaryon except 36-MI 103, which showed only 49% genetic similarity. In addition, genetic similarity degrees were classified into four groups: I (parental dikaryon), II (fast growing type), III (moderate growing type), and IV (slow growing type). However, there is no correlation between mating type and mycelial growth rates.

• Fisheries and Aquatic Sciences
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• v.8 no.2
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• pp.51-55
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• 2005

We measured the anti-attachment activity of allelochemical and antifouling substances using monospores from Porphyra yezoensis Ueda as an assay. Methanol or aqueous extracts ($20/{\mu}g/mL$) from 32 seaweeds were added to monospore suspensions. Methanol extracts of Corallina pilulifera, Ishige sinicola, Sargassum horneri, and Sargassum sagamianum inhibited attachment $by\;>90\%$ compared to the reference. Phenolic compounds fractionated from S. sagamianum caused the most potent inhibition. P. yezoensis monospores also showed significant sensitivity to known allelochemical and algicidal compounds.

• Journal of Plant Biology
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• v.13 no.2
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• pp.1-10
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• 1970

This experiment surveys ecological and morphological phase on Prasiola sp. in the mountain torrent of Chodang-ri, Keunduck-myon, Samchuck-gun, Kangwon-do, Korea from November 1968 through January 1970 and the results obtained were summarized as follows. 1. The temperature of the surface water was 12.4$\pm$2.3$^{\circ}C$, and pH was 7.25$\pm$0.2. 2. The external forms of thallus are very variable, but its basic form likely lanceolated and ovated. 3. The length of thallus is 0.6cm-8.8cm (3.6$\pm$1.72cm), and the width, 0.2cm-5.5cm(1.7$\pm$0.92cm). (The inside of the parentheses the average for 500 individuals). 4. It is observed that thallus at the time of formation of a monospore is a monostratum cell whose thickness is 21$\pm$3.2$\mu$. 5. Thickness of thallus at the transveres section at the time of heteroplanogametes formation is 29.9$\pm$2.2$\mu$, and that of the female gametes cell is 6.3$\pm$1.7$\times$6.3$\pm$0.8$\mu$, and that of the male gametes cell is 2.8$\pm$0.6$\times$28.1$\pm$1.1$\mu$. 6. As for growth, it begins with apical growth, followed by marginal growth. It seems to grow, through cell division when microsopical papillae are produced in growth line cell of marginal rigion thus by fusioning microscopical papillae. 7. The two kinds of thallus, one produced from a monospore and other from a planozygotes, are both haplonts and observed as n-3. 8. It seems that a thallus sprouts in April and increases its number through a asexual reproduction by a monospore and begins a sexual reproduction in November by forming gametes. 9. Female gametes are produced 16 from one thallus cell, whose structure shows 8 cells in the surface view and 4 layers in transverse section. Male gametes are produced 128 from one thallus cell, 16 cells surface, 8 layers in transverse section.

• Journal of Life Science
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• v.26 no.4
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• pp.484-489
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• 2016

Living organisms can maintain or extend their territories by producing allelochemicals that influence the growth, survival, and reproduction of other organisms. To identify natural biostimulants of positive allelochemicals, we screened 18 common seaweed extracts for enhancement of rhizoid and blade production in a convenient Porphyra suborbiculata monospore assay. By addition of methanolic extract from the most potent green seaweed, Codium fragile, 100% and 50% enhancement doses reflecting the amount of C. fragile extract required to enhance rhizoid formation (in terms of number of spores with rhizoids per total spores tested) were approximately 100 and 50 μg/ml, respectively, in the P. suborbiculata monospore culture. The C. fragile extract quickly enhanced rhizoid formation, rhizoid numbers per rhizoid-holding spore, rhizoid length, blade formation (in number of spores with blade per total spores tested), and blade length from most monospores at early culture days. The extract enhanced rhizoid formation after 2 days of culture significantly, rhizoid numbers per rhizoid-holding spore after 3 days, rhizoid length after 3 days, blade formation after 2 days, and blade length after 1 day, respectively, from most monospores. The allelochemicals that enhanced favorite seaweed species may be efficacious for new seaweed management technologies, including the development of biostimulant agents based on natural products.

• 한국수산학회:학술대회논문집
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• 2005.05a
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• pp.176-177
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• 2005

• The Plant Pathology Journal
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• v.33 no.2
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• pp.109-117
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• 2017

Tan spot caused by the fungus Pyrenophora triticir-repentis is a serious disease of wheat, which is on increase in recent years in Mediterranean region. In the field this fungus produces a diamond-shaped necrotic lesions with a yellow halo on wheat foliage. The objective of this study was to characterize and compare several monospore isolates of P. tritici-repentis collected from different infected wheat fields in various locations of Algeria, and find the morphological differences between them, if any. The results revealed wide morphologically variation among the isolates based on colony colors and texture, mycelial radial growth and conidial size.

• Korean Journal of Veterinary Service
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• v.30 no.2
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• pp.283-286
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• 2007

Fungus generally doesn't produce toxic or harmful substances so it has low chances to cause food poisoning. However it leads to change appearance, odor and characteristics of the contaminated foods and result in sanitary risk problems. Therefore the contamination of fungi should be prevented since they are not proper for human consumption. Green fungi with white outline raised from the air cell of cooked eggs which were collected by Gyeongi Livestock Veterinary Service in August, 2006. The results came out after the cultivation using Sabouraud's Dextrose Agar(SDA). The conidium appeared white and monospore, the shape of colony was round and oval. Conidiophore was brown and granulated and wrinkles and formed. It was confirmed as Aspergillus nidulans based on the dying using Lactophenol cotton blue, the observation of septum and vesicle from the grown spores, and rDNA sequencing.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.1
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• pp.1-8
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• 2012

The objective of the present study was carried out to clarify the effects of deep sea water on the growth and maturation of $Porphyra$ (Rhodophyta, Bangiales). Foliose thalli for indoor culture were collected from Yeongok ($P.$ $okamurae$) in Gangwon Prefecture, Tongyeong ($P.$ $suborbiculata$ f. $latifolia$) and Namhae ($P.$ $yezoensis$ f. $narawaensis$) in Gyongnam Prefecture respectively. Monospores were cultured at five temperatures (5, 10, 15, 20 and $25^{\circ}C$) with a photon irradiance of $80{\mu}m^{-2}s^{-1}$ under photoperiods of 14L:10D and 10L:14D in surface, deep and mixed seawater in respectively. The fast growth of foliose thalli were observed in $P.$ $suborbiculata$ f. $latifolia$ cultured at deep seawater under $15^{\circ}C$ and 10L:14D. In three species, the optimum growth occurred at 10 and $15^{\circ}C$ under deep and mixed seawater and short day-length. In general, monospores from the cultured thalli were liberated within three weeks after incubation under $10-25^{\circ}C$ and both photoperiods. From the result of this study, deep seawater is considered that the natural species of the genus $Porphyra$ can be useful for the development as the new cultivars.

• Journal of Mushroom
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• v.4 no.2
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• pp.48-52
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• 2006

Oyster mushroom, Pleurotus ostreatus is bifactorial heterothallism. Single basidiospore isolates from fruiting bodies are homokaryotic and self-sterile. However, we found that homokaryons derived from some strains of P. ostreatus could develop fruiting bodies with two different types. One hundred and two isolates out of 155 monospore isolates formed fruiting bodies (65.8%). First group did not have only mature or sporulating fruiting bodies but also clamp connections, which initial isolate also did not present clamp connections (Abortive homokaryotic fruiting, AHF). Second group had developed fruiting bodies with clamp connections even though initial homokaryotic colony did not form clamp connections (Pseudo- homokaryotic fruiting, PHF). The mycelial colonies derived from PHF by tissue culture formed clamp connections, while mycelial colonies of AHF lacked them. We obtained 535 PHF and 79 AHF inter-strain hybrids among 8 strains of P. ostreatus by hyphal anastomosis. The fruiting body yield of PHF group is higher than that of AHF group in bottle cultivation. A preselection of single spore isolates for fertility would save labour in strain improvement of P. ostreatus.

• Journal of Mushroom
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• v.5 no.1
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• pp.34-38
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• 2007

The white-colored and the dark gray-colored mutants were frequently happened in cultivated areas of Pleurotus ostreatus (Wonhyeong-neutari). These caused conflicts between farmers and spawn companies. Our studies were conducted to elucidate the mechanism of mutagenesis. The results from the studies would provide valuable informations that could be used to prevent the color-related mutation, and also will be applied in breeding programs of P. ostreatus. Oyster mushroom variety, Wonhyeong-neutari, is somatic hybrid of Pleurotus and has genetic makers for arginine, ornithine, proline, riboflavine. Genetic markers analysis of monospore isolates derived from color mutants show identical tendency with that of Wonhyeong-neutari, these results indicate that color mutants were derived from Wonhyeongneutari. Twenty-one and four homokaryons were selected from the white-colored mutant MGL 2205 and gray-colored ASI 2029. All 34 F1 hybrids derived from the white-colored mutant MGL 2205 produce white-color fruiting bodies, indicating that the white color trait is heritable. In the first generation hybrids between the white-colored MGL 2205 and the gray-colored ASI 2029, all 16 hybrids produced pigmented fruiting bodies. Homokaryons isolated from the hybrid MGL 2205 X ASI 2029 were mated with homokaryon tester strains derived from MGL 2205. By these result, we could assumed that white color trait is a heritable character which is controlled by more than one recessive gene.