• Mycobiology
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• v.36 no.1
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• pp.74-76
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• 2008

To obtain basic information on the biochemical property of basidiospores of shiitake mushroom (Lentinula edodes), the ability of producing extracellular enzyme was assessed using a chromogenic plate-based assay. For the aim, amylase, avicelase, $\beta$-glucosidase, CM-cellulase, pectinase, proteinase, and xylanase were tested against monokaryotic strains generated from forty basidiospores of two different parental dikaryotic strains of shiitake mushroom, Sanjo-101Ho and Sanjo-108Ho. These two parental strains showed different degree of extracellular enzyme activity. No identical patterns of the degree of enzyme activity were observed between monokaryotic strains and parental strains of the two shiitake cultivars. The degree of extracellular enzyme activity also varied among monokaryotic strains of the two shiitake cultivars. Our results showed that dikaryotic parental strains of shiitake mushroom produce monokaryotic basidiospores having very diverse biochemical properties.

• Mycobiology
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• v.43 no.1
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• pp.24-30
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• 2015

The effects of monokaryotic strains on fruiting body formation of Lentinula edodes were examined through mating and cultivation of the mated dikaryotic mycelia in sawdust medium. To accomplish this, monokaryotic strains of L. edodes were isolated from basidiospores of the commercial dikaryotic strains, Chamaram (Cham) and Sanjo701 (SJ701). A total of 703 matings (538 self-matings and 165 outcrosses) were performed, which generated 133 self-mates and 84 outcross mates. The mating rate was 25% and 50% for self-mating and outcross, respectively. The bipolarity of the outcross indicated the multi-allelic nature of the mating type genes. The mating was only dependent on the A mating type locus, while the B locus showed no effect, implying that the B locus is multi-allelic. Next, 145 selected dikaryotic mates were cultivated in sawdust medium. The self-mated dikaryotic progenies showed 51.3% and 69.5% fruiting rates for Cham and SJ701, respectively, while the fruiting rate of the outcross mates was 63.2%. The dikaryotic mates generated by mating with one of the monokaryotic strains, including A20, B2, E1, and E3, showed good fruiting performance and tended to yield high fruiting body production, while many of the monokaryotic strains failed to form fruiting bodies. Overall, these findings suggest that certain monokaryotic strains have traits enabling better mating and fruiting.

• Mycobiology
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• v.43 no.1
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• pp.81-86
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• 2015

To promote the selection of promising monokaryotic strains of button mushroom (Agaricus bisporus) during breeding, 61 progeny strains derived from basidiospores of two different lines of dikaryotic parental strains, ASI1038 and ASI1346, were analyzed by nucleotide sequencing of the intergenic spacer I (IGS I) region in their rDNA and by extracellular enzyme assays. Nineteen different sizes of IGS I, which ranged from 1,301 to 1,348 bp, were present among twenty ASI1346-derived progeny strains, while 15 different sizes of IGS I, which ranged from 700 to 1,347 bp, were present among twenty ASI1038-derived progeny strains. Phylogenetic analysis of the IGS sequences revealed that different clades were present in both the ASI10388- and ASI1346-derived progeny strains. Plating assays of seven kinds of extracellular enzymes (${\beta}$-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease) also revealed apparent variation in the ability to produce extracellular enzymes among the 40 tested progeny strains from both parental A. bisporus strains. Overall, this study demonstrates that characterization of IGS I regions and extracellular enzymes is useful for the assessment of the substrate-degrading ability and heterogenicity of A. bisporus monokaryotic strains.

• Mycobiology
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• v.45 no.4
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• pp.379-384
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• 2017

In mating of Lentinula edodes, dikaryotic strains generated from certain monokaryotic strains such as the B2 used in this study tend to show better quality of fruiting bodies regardless of the mated monokaryotic strains. Unlike B2, dikaryotic strains generated from B16 generally show low yields, with deformed or underdeveloped fruiting bodies. This indicates that the two nuclei in the cytoplasm do not contribute equally to the physiology of dikaryotic L. edodes, suggesting an expression bias in the allelic genes of the two nuclei. To understand the role of each nucleus in dikaryotic strains, we investigated single nucleotide polymorphisms (SNPs) in laccase genes of monokaryotic strains to reveal nuclear origin of the expressed mRNAs in dikaryotic strain. We performed reverse transcription PCR (RT-PCR) analysis using total RNAs extracted from dikaryotic strains (A5B2, A18B2, and A2B16) as well as from compatible monokaryotic strains (A5, A18, and B2 for A5B2 and A18B2; A2 and B16 for A2B16). RT-PCR results revealed that Lcc1, Lcc2, Lcc4, Lcc7, and Lcc10 were the mainly expressed laccase genes in the L. edodes genome. To determine the nuclear origin of these laccase genes, the genomic DNA sequences in monokaryotic strains were analyzed, thereby revealing five SNPs in Lcc4 and two in Lcc7. Subsequent sequence analysis of laccase mRNAs expressed in dikaryotic strains revealed that these were almost exclusively expressed from B2-originated nuclei in A5B2 and A18B2 whereas B16 nucleus did not contribute to laccase expression in A2B16 strain. This suggests that B2 nucleus dominates the expression of allelic genes, thereby governing the physiology of dikaryons.

• 한국균학회소식:학술대회논문집
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• 2014.10a
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• pp.41-41
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• 2014

Agaricus bisporus, commonly known as the button mushroom, is the most widely cultivated species of edible fungi. Low frequency of recombination ratio and homokaryotic or monokaryotic spore on meiotic basidia form obstacles for breeding programs. Since the first hybrid varieties for white button mushrooms were released in Europe, new varieties released afterwards were either identical of very similar to these first hybrids on morphologies. Therefore, different DNA markers have been used to define unique varieties of A. bisporus strains. Aim of this study is to assess the genetic diversity of different A. bisporus strains in Korea. Twelve UFP (Universal fungal primer, JK BioTech. Ltd), 12 simple sequence repeat (ISSR) and 30 SSR primers were used to assess genetic diversity of monokaryotic and dikaryotic Agaricus bisporus strains including other 19 Agaricus spp. Of them, four UFP, four SSR primers, $(GA)_8T$, $(AG)_8YC$, $(GA)_8C$ and $(CTC)_6$ and seven SSR markers produced PCR polymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted for UPGMA cluster analysis. Forty five strains of A. bisporus are genetically clustered into 6 groups, showing coefficient similarity from 0.75 to 0.9 among them. In addition, genetic variations of monokaryotic and dikaryotic Agaricus bisporus strains were partially detected by PCR technologies of this study. The varieties, Saea, saedo, Saejeong and Saeyeon that have recently been developed in Korea were involved in the same group with closely genetic relationship of coefficient similarity over 0.96, whereas, other strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.83-90
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• 2017

In order to develop the culture material for breeding of Lentinula edodes, dikaryotic and monokaryotic mycelia were cultured in agar and sawdust medium. The cultivars were used Sanjo No. 701, Sanjo No. 705, Chamaram and Chuje No. 2 in this study. The mycelial growth of the cultivars were highest in PDA except for Sanjo No. 705, but Sanjo No. 705 showed the best mycelial growth in MCM. Regardless of the cultivars, the mycelial growth showed the most stable in MEA. There was no significant difference in mycelial growth among the cultivars in sawdust medium, but it was about 10% faster than that of Sanjo No. 701 and 705. Monokaryotic strains of Sanjo No. 701 and Chamaram showed less mycelial growth than dikaryotic mycelium. Dikaryotic mycelium of Chamaram showed better mycelial growth than that of Sanjo No. 701, but monokaryotic mycelium of Chamaram showed lower mycelial growth than Sanjo No. 701. The selected monokaryotic mycelium has a wide varience of mycelial growth, and the morphologies of the colonies are very diverse, so those are presumed that wide variences of monokaryotic are selected in genetically, and these monokaryotic mycelium are expected to be a good breeding materials.

• The Korean Journal of Mycology
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• v.39 no.2
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• pp.99-104
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• 2011

Shiitake breeding requires the procedures of mating of two different parental strains and selection of hybrid strains that have good traits for the mushroom production. In this study, we tested the possibility of the use of chromogenic plate-based assay for extracellular enzyme production in order to assess and find good biochemical properties-possessed hybrid strains that were generated from genetic cross of the monokaryotic strains derived from two different parental strains of Lentinula edodes Sanjo-101ho and Sanjo-108ho. We observed that there was difference in the ability of producing ${\beta}$-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease among the monokaryotic strains. We could also comparatively assess that the ability of the seven extracellular enzymes production in the hybrid strains depended on the mating combination of the monokaryotic strains. Our results demonstrate that the assessment method for extracellular enzyme production using chromogenic plate assay could be usefully applied to the assessment of the hybrid strains derived from the breeding procedure of L. edodes.

• Journal of Mushroom
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• v.10 no.3
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• pp.101-108
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• 2012

Pleurotus ostreatus 'Miso' is a mutant strain showing white color in pileus from the known parent strain 'Wonhyeong 1'. Shape and several other characters also vary with culture conditions. Mating experiments were performed to understand interstrain mating relationship using monokaryons of the parent and the mutant strains. All monokaryons were grown from single spores isolated from freshly collected fruit bodies. Pairings were performed in 90 mm petri dishes on PDA. They were allowed to grow at 25 until two fronts of the advancing mycelia met and developed a conspicuous contact zone. The contact zone and the outer edges of paired colonies on each plate were examined for clamp connections. The parent and the mutant resulted in tetrapolar incompatibility in intrastrain crosses. In interstrain crosses, each monokaryotic tester strain of the parent strain was out-crossed to monokaryotic tester strains of the mutant. As a result of these crosses it was found that both strains share the same A and B incompatibility factors yielding 25% compatibility.

• The Korean Journal of Mycology
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• v.50 no.4
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• pp.263-274
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• 2022

Lentinula edodes is an important commercial mushroom and there have been several reports of viral infections in L. edodes. Two mycoviruses (LeV-HKB and LeNSRV1) were detected in Sanbaekhyang (NIFoS 2778) and Taehyanggo (NIFoS 4317), the sawdust-cultivated commercial strains. The vertical transmission rates of the viruses were investigated by detecting the viruses in 80 monokaryotic strains derived from basidiospores isolated from the fruiting bodies of each strain. Most of the monokaryotic strains were infected with the virus and the two viruses showed different levels of meiotic stability, with LeV-HKB showing higher meiotic stability than LeNSRV1. Therefore, it seems that the vertical transmission mechanism of mycoviruses is different depending on the virus species. We also examined the mycelial growth rate of the monokaryotic strains and compared the growth rate according to virus infection status. Although there was no statistically significant correlation between viral infection and mycelial growth rate, we found that the average growth rate was reduced by additional virus infection. We expect our data to contribute to a greater understanding of the mechanism of the vertical transmission of mycoviruses, and promoting breeding using virus-free monokaryotic strains.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.460-464
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• 2013

dsRNA was found in malformed cultures of Lentinula edodes strain FMRI0339, one of the three most popular sawdust cultivated commercial strains of shiitake, and was also found in healthy-looking fruiting bodies and actively growing mycelia. Cloning of the partial genome of the dsRNA revealed the presence of the RdRp sequence of a novel L. edodes mycovirus (LeV), and sequence comparison of the cloned amplicon showed identical sequences sequence to known RNA-dependent RNA polymerase genes of LeV found in strain HKA. The meiotic stability of dsRNA was examined by measuring the ratio of the presence of dsRNA among sexual monokaryotic progeny. More than 40% of the monokaryotic progeny still contained the dsRNA, indicating the persistence of dsRNA during sexual reproduction. Comparing the mycelia growth of monokaryotic progeny suggested that there appeared to be a tendency toward a lower frequency of virus incidence in actively growing progeny.