• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.493-503
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• 2021

Tricholoma matsutake (Pinus mushroom, PM) is one of the most valued ectomycorrhizal fungi in Asia because it is an expensive forest product with a unique flavor and taste. Therefore, many studies have tried to successfully cultivate Tricholoma matsutake artificially in Korea and other countries. However, its physiological and ecological characteristics are still unknown. Thus, we need to understand the diversity and clusters of microorganisms related to Tricholoma matsutake and to identify their core microorganisms related to their growth and production. In this study, we obtained an average of 11,661 fragments from three pine mushrooms with metagenome (an assemblage of genes of all microorganisms in the natural world) analysis from a pine forest located in Pohang, Gyeongsang-Bukdo. Of these, the valid reads were on average 5,073 per sample available for analysis, and the average length of a read was 456 bp. There were an average of 33.3 phyla in the metagenome analysis. Firmicutes phylum made up on an average 46% of the phyla and was dominant among the phyla. The next dominant phylum was Proteobacteria at 27% followed by Bacteroidetes at 17%, Actinobacteria at 5% and Verrucomicrobia at 2%. The Proteobacteria phylum consisted of the γ-proteobacteria class at 54% followed by β-proteobacteria at 37%, α-proteobacteria at 6%, δ-proteobacteria at 2% and ζ-proteobacteria at 0%. The metagenome consisted of the Ruminococcaceae family at 17% followed by Pseudomonadaceae at 13%, Burkholderiaceae at 7%, Bacteroidaceae at 7%, Lachnospiraceae at 7% and Clostridiaceae at 6%.

• The Korean Journal of Mycology
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• v.49 no.4
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• pp.507-514
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• 2021

Lentinula edodes have been cultivated extensively not only in South Korea but also in other Asian countries. In terms of taste and nutrition, it is a valuable mushroom that is comparable to other mushrooms. L. edodes contains various physiologically active compounds that promote human health. One compound, ergothioneine, exerts a powerful antioxidant function that inhibits cellular senescence. As it is not biosynthesized by plants or animals, L. edodes is very important for ergothioneine supply. The L. edodes cultivars Bambithyang (NIFoS 3404) and Sansanhyang (NIFoS 3420) of the National Institute of Forest Science (NIFoS) had higher ergothioneine content than the other cultivars, and 11 strains were obtained using mono-mono hybridization between them. The strains were inoculated into sawdust media to obtain fruiting bodies, and the ergothioneine content of each hybrid strain was confirmed using high-performance liquid chromatography (HPLC) analysis. Among the 11 strains, NIFoS 5108 had a higher ergothioneine content than the parental strains, Bambithyang (NIFoS 3404) and Sansanhyang (NIFoS 3420). This study revealed that it is possible to develop cultivars with improved specific functions using mono-mono hybridization.

• The Korean Journal of Mycology
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• v.48 no.4
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• pp.389-396
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• 2020

Lentinula edodes is one of the most widely consumed edible mushrooms in Korea. Mating in L. edodes is regulated by a tetrapolar system, and two unlinked genetic loci, A and B, are known to be major determinants of the mating types, as reported in other heterothallic basidiomycetes. The A locus of L. edodes encodes a pair of homeodomain (HD) transcription factors. The highly variable N-termini of these HD transcription factors contribute to the diversity among the A mating types. In this study, we developed a cleaved amplified polymorphic sequence (CAPS) marker to discriminate 11 different A mating type alleles predominant among both cultivated and wild strains. Amplification of the variable region of the A locus followed by digestion with HaeIII and EcoRI restriction enzymes enabled successful discrimination among the 11 A mating type alleles. We also evaluated the applicability of this method in the identification of two A mating types of a dikaryotic strain.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.296-299
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• 2016

Lentinula edodes is an edible mushroom that contains a ${\beta}$-glucan called lentinan, which has antitumor and immune-enhancing properties. In the present study, the ${\beta}$-glucan contents of L. edodes mushrooms cultivated on sawdust with different nutritional supplements and fruiting temperatures were measured using a commercial ${\beta}$-glucan assay kit purchased from Megazyme (Bray, Ireland). The weight loss of sawdust media and the yield of fruiting bodies showed similar trends, but the yield was more closely associated with the nutritional supplements used than the weight loss of sawdust media was. The ${\beta}$-glucan contents of L. edodes were 39.5-42.1%, except in the bean curd refuse + $CaCl_2$ supplementation group (50.4%). Furthermore, the ${\beta}$-glucan content decreased with increasing temperatures and was 42.4% at a low fruiting temperature.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.289-295
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• 2016

Lentinula edodes is an edible wild mushroom that can be found in mountainous regions of the Korean peninsula. Wild oak mushrooms were collected from Quercus mongolica at an elevation of more than 1,000 m on Mt. Jungwang and Mt. Gariwang in Gangwon province. We examined 10 oak mushroom strains to evaluate the genetic similarity among strains. Genetic similarity was determined based on the analysis of microsatellite markers (Led A2, Led A8, Led B2, Led B6, and Led D6) registered in the National Center for Biotechnology Information. We also performed dual culture tests on potato dextrose agar for 2 months at $25^{\circ}C$. The observed heterozygosity across all microsatellites ranged from 0.00 and 0.60 among 5 microsatellite markers, and the polymorphism information content values of Led A2, Led A8, Led B2, Led B6, and Led D6 were 0.0000, 0.8144, 0.6194, 0.4892, and 0.5702, respectively (mean value = 0.4987). Confrontation lines between strains were formed for almost all combinations. In conclusion, the oak mushroom populations of Mt. Jungwang and Mt. Gariwang have mixed gene pools. However, further studies are needed to identify genetic similarities and variations among these populations.

• The Plant Pathology Journal
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• v.38 no.5
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• pp.472-481
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• 2022

Brown blotch disease, caused by Pseudomonas tolaasii, is one of the most serious diseases in mushroom cultivation, and its control remains an important issue. This study isolated and evaluated pathogen-specific bacteriophages for the biological control of the disease. In previous studies, 23 varieties of P. tolaasii were isolated from infected mushrooms with disease symptoms and classified into three subtypes, Ptα, Ptβ, and Ptγ, based on their 16S rRNA gene sequences analysis and pathogenic characters. In this study, 42 virulent bacteriophages were isolated against these pathogens and tested for their host range. Some phages could lyse more than two pathogens only within the corresponding subtype, and no phage exhibited a wide host range across different pathogen subtypes. To eliminate all pathogens of the Ptα, Ptβ, and Ptγ subtype, corresponding phages of one, six, and one strains were required, respectively. These phages were able to suppress the disease completely, as confirmed by the field-scale on-farm cultivation experiments. These results suggested that a cocktail of these eight phages is sufficient to control the disease induced by all 23 P. tolaasii pathogens. Additionally, the antibacterial effect of this phage cocktail persisted in the second cycle of mushroom growth on the cultivation bed.

• Journal of Mushroom
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• v.18 no.3
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• pp.179-188
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• 2020

The oak mushroom (Lentinula edodes) is a popular edible mushroom that has long been cultivated and eaten throughout Northeast Asia (including Korea). Its taste and flavor are unique. Oak mushrooms are cultivated on logs and in sawdust. The cultivation period on logs is 4-5 years, while the cultivation period in sawdust is 6 months, which is rapidly driving a shift from log to sawdust based cultivation. In particular, the Sanjo 701ho cultivar of L. edodes is a mid-range to high-temperature variety that is widely known for its suitability for summer cultivation on sawdust in Korea. This study summarizes new developments and achievements in the oak mushroom industry in Korea, and details the cultivation history of Sanjo 701ho, its culturing characteristics, various demonstration tests, and the expansion of domestic varieties.

• The Korean Journal of Mycology
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• v.47 no.4
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• pp.385-392
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• 2019

Currently, plastic bags are being used for sawdust cultivation of shiitake mushroom. However, due to serious environmental problems caused by the use of plastic bags, we studied the efficacy of bottle cultivation method to replace the sawdust bag method. Small detachable plastic bottles (400 g capacity) filled with Quercus spp. sawdust and wheat bran (4:1 w/w) media were incubated for 80 and 120 days. The weight loss (%) of the media was higher for the NIFoS 2464 strain at an approximate light intensity of 300 Lux than light intensity of 500 Lux; the light intensity was associated with the loss of sawdust medium-weight during the cultivation period. The highest yield was observed when the strain was cultivated for 80 days under dark conditions, 40 days under 500 Lux light, and air circulation fan speed of 30 rpm. When incubated for 120 days, mushroom yield in the bottle media was higher at 40 days of light exposure than 20 days of light exposure. In the bottle media incubated for 80 days under dark conditions, the mushrooms fruited due to repetitive water spraying on the top of the media and light stimulation during the fruiting period. The media could be separated from the bottles because the media shrank after the first harvest. These separated plastic bottles could be re-used for mushroom cultivation, thereby reducing the amount of plastic waste.

• Journal of Mushroom
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• v.18 no.2
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• pp.145-150
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• 2020

A new cultivar, 'Bambithyang', was bred from monokaryotic strains of Sanbaekhyang and SANJO 707ho using the mono-mono hybridization method. Its incubation period was determined to be 100 days and its optimum temperature for fruit body flushing, 11-20℃. The mushrooms had a convex cap (diameter, 69.6 mm; thickness, 15.2 mm) and stipes in their center. The color of their upper sides was chestnut brown; their gills were arranged in a ripple style and had medium density. Their scales were cream-colored and fully distributed; the stipes were cream-colored and cylindrical (thick upper part). They also had cream colored fluffs and sporadic fruiting bodies. Zone lines were present when they were cultivated with mother and father varieties. Their stipe lengths and caps were 9% shorter and 16.9% thicker, respectively, than those of Sanbaekhyang.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.188-195
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• 2017

Despite the high commercial value of the pine mushroom (Tricholoma matsutake) around the world, its production still depends upon natural harvesting. In recent years, mushroom researchers in Korea and Japan have been successful in artificially cultivating T. matsutake by producing single mushroom through matsutake-infected pine seedlings. In this study, we determined the minimum seedling height required for the survival of matsutake mycelia in the infected pine seedlings in the field. The survival rate of matsutake mycelia in the matsutake-infected pine seedlings was 50% (14) in two years and 71% (10) in one year after their transplantation. The average height at time of transplantation of the matsutake-infected pine seedlings that bore surviving mycelia after transplantation was 25 cm (minimum 12 cm to maximum 40 cm). In conclusion, the matsutake mycelium of matsutake-infected pine seedlings was able to survive in field conditions if the height of the seedling at the time of T. matsutake infection was at least 12 cm. These results suggest that the height of the host plants used in conventional matsutake-infected pine seedling production should be greatly reduced to improve the matsutake cultivation. Therefore, standardization of the seedling height for artificial cultivation of pine mushrooms by the matsutake-infected pine seedling method is suggested.