• Weed & Turfgrass Science
• /
• v.4 no.2
• /
• pp.135-143
• /
• 2015

Typhula ishikariensis Imai is a causal agent of Typhula snow mold, one of the most important turfgrass diseases in northern regions of the United States. Within Wisconsin isolates, there are three district groups clustered with known isolates of T. ishikariensis var. ishikariensis, var. canadensis and var. idahoensis as identified by RAPD markers. To further investigate the genetic relationship among these groups (varieties), monokaryon-monokaryon and dikaryon-monokaryon mating experiments were conducted. Mating types from var. ishikariensis, var. canadensis and var. idahoensis isolates were paired in all possible combinations. Pairings between var. canadensis and var. idahoensis were highly compatible, while no compatibility was detected between var. ishikariensis and either var. canadensis or var. idahoensis. These results indicate that var. ishikariensis is genetically separated from var. canadensis and var. idahoensis, whereas var. canadensis and var. idahoensis appeared to be genetically related to each other as a taxonomic unit. In the genetic relationship with the known biological species, var. ishikariensis and var. canadensis were genetically related to biological species I and II, respectively. However, var. idahoensis was not compatible with any of the biological species, suggesting that the pathogen may be in the process of biological speciation from var. canadensis.

• The Korean Journal of Mycology
• /
• v.42 no.1
• /
• pp.86-90
• /
• 2014

Button mushroom (Agaricus bisporus) strains from diverse origins were compared in this study to obtain basic information on their growth and biochemical properties that are helpful for breeding. Among 31 dikaryotic strains tested, most strains showed better mycelial growth on oatmeal agar than on MEA and PDA. Mycelia of the mushroom strains revealed ${\beta}$-glucosidase activity the most clearly among the seven extracellular enzymes tested. All the strains showed protease activity, but ${\beta}$-glucosidase activity was found in 27 strains and xylanase activity was found in 30 strains. The activity of avicelase, CM-cellulase, amylase, and pectinase was detected in less than 20 strains. These results implied that enzymatic characteristics could be used as a criterion of strain selection for breeding study.

• Korean Journal of Microbiology
• /
• v.30 no.2
• /
• pp.78-82
• /
• 1992

The dikaryon of Trimorphonzycc,.~ papilioncicc.ous, one of basidiornycetous yeast needed thiamine as a growth factor and required relatively simple nutrient components. This organism grem best at 25$^{\circ}$C. anci showed broad pH range (pH 4.0-7.0). It was groM,n in liquid minimal media with various carbon sources and they could be classilied into 3 groups as follows. Glucose. fructose. mannose, sucrose and xylose (A gi.oup) supportecl good growth (>OD 0.8), and showed poor laccase activity (less than 1.5 u'mg protein). Galactose and gluconate (B group) showed moderate growth (01) 0.3-0.6). and hail moderatc crlzyrne activity (4-6u). Arabinosc. lactose. maltose ant1 pyruvate (C 5roup) showed poor growth (OD 0.1-0.2). and showed high enzyme activity (higher than 8 u). Kibosc, acetate. citrate. lactate and oxaloacetate showed no growth. When the yeast was grown in a medium which had two carbon sources (glucose and arabinose). laccase was regul;~tecl by the cutahoiitc repression.

• Journal of Mushroom
• /
• v.9 no.1
• /
• pp.3-16
• /
• 2011

In the bipolar basidiomycete Pholiota nameko, a pair of homeodomain protein genes located at the A mating-type locus regulates mating compatibility. In the present study, we used a DNA-mediated transformation system in P. nameko to investigate the homeodomain proteins that control the clamp formation. When a single homeodomain protein gene (A3-hox1 or A3-hox2) from the A3 monokaryon strain was introduced into the A4 monokaryon strain, the transformants produced many pseudo-clamps but very few clamps. When two homeodomain protein genes (A3-hox1 and A3-hox2) were transformed either separately or together into the A4 monokaryon, the ratio of clamps to the clamp-like cells in the transformants was significantly increased to approximately 50%. We, therefore, concluded that the gene dosage of homeodomain protein genes is important for clamp formation. When the sip promoter was connected to the coding region of A3-hox1 and A3-hox2 and the fused fragments were introduced into NGW19-6 (A4), the transformants achieved more than 85% clamp formation and exhibited two nuclei per cell, similar to the dikaryon (NGW12-163 ${\times}$ NGW19-6). The results of real-time RT-PCR confirmed that sip promoter activity is greater than that of the native promoter of homeodomain protein genes in P. nameko. So, we concluded that nearly 100% clamp formation requires high expression levels of homeodomain protein genes and that altered expression of the A mating-type genes alone is sufficient to drive true clamp formation.

• Korean Journal of Microbiology
• /
• v.43 no.2
• /
• pp.147-149
• /
• 2007

White-rot fungi which degrade lignin can also degrade diverse recalcitrant compounds such as polymeric dyes, explosives, pesticides, and endocrine disrupting chemicals. Lignin degrading enzymes are involved in the degradation reactions, and introduction of foreign genes into a white-rot fungus is required in order to increase the degrading capacity. Genetic transformation experiment has been carried out in Irpex lacteus and Phlebia tremellosa to an antibiotic resistance. The transformation yields were 50-70 transformants/${\mu}g$ DNA and 15-25 transformants/${\mu}g$ DNA in I. lacteus and P. tremellosa, respectively. The stable replication of the plasmid was confirmed by PCR using the plasmid-specific primers, and many mutants were generated during this integration in both fungi.

• Mycobiology
• /
• v.46 no.4
• /
• pp.407-415
• /
• 2018

Pheromone (PHB)-receptor (RCB) interaction in the mating pheromone response pathway of Lentinula edodes was investigated using synthetic PHBs. Functionality of the C-terminally carboxymethylated synthetic PHBs was demonstrated by concentration-dependent induction of a mating-related gene (znf2) expression and by pseudoclamp formation in a monokaryotic strain S1-11 of L. edodes. Treatment with synthetic PHBs activated the expression of homeodomain genes (HDs) residing in the A mating type locus, and of A-regulated genes, including znf2, clp1, and priA, as well as genes in the B mating type locus, including pheromone (phb) and receptor (rcb) genes. The synthetic PHBs failed to discriminate self from non-self RCBs. PHBs of the B4 mating type (B4 PHBs) were able to activate the mating pheromone response pathway in both monokaryotic S1-11 and S1-13 strains, whose B mating types were B4 (self) and B12 (non-self), respectively. The same was true for B12 PHBs in the B4 (non-self) and B12 (self) mating types. The synthetic PHBs also promoted the mating of two monokaryotic strains carrying B4-common incompatible mating types ($A5B4{\times}A1B4$). However, the dikaryon generated by this process exhibited abnormally high content of hyphal branching and frequent clamp connections and, more importantly, was found to be genetically unstable due to overexpression of mating-related genes such as clp1. Although synthetic PHBs were unable to discriminate self from non-self RCBs, they showed a higher affinity for non-self RCBs, through which the mating pheromone response pathway in non-self cells may be preferentially activated.

• Journal of Mushroom
• /
• v.13 no.3
• /
• pp.217-222
• /
• 2015

This study was conducted to obtain a growth correlation of basal information from the development of disease resistant Flammulina velutipes cultivars through back-crossing between the strains of wild-type brown monokaryon 4019-20 and the derivative of commercial quality white monokaryons 3. The two strains were selected to back-cross for further enhancing their latent attributes and growth characteristics. The parents of 4019-$20{\times}M3$ back-crossed to reproduce $F_1$, M3-Sn. Using $F_1$, M3-Sn procured and isolated into 94 monokaryon strains. Further examination of growth characteristics carried out by back-crossing between M3 and $BC_1F_1$ from M3-n dikaryon. Monokaryon exhibited an irregular growth pattern and demonstrated to be sluggish development in the sawdust medium. However $BC_1F_1$(M3-n) dikaryon strains confirmed mostly regular growth pattern and demonstrated ordinary growth in the sawdust medium. The fruitbody of $BC_1F_1$ confirmed as light-brown colour to be the dominant gene. The colour distributions of fruitbody, $BC_1F_1$, resulted as follows; 7% of dark brown, 25% of brown, 27% of light brown, 16% of ivory and 25% of white. The ratio of the other color to white showed 3 to 1 which suggested two major genes were related to fruitbody color.

• Journal of Life Science
• /
• v.24 no.11
• /
• pp.1174-1179
• /
• 2014

This research was carried out to evaluate whether gamma ray is a useful tool for breeding new strains of mushrooms. For this research, 5 mutant groups, 20 strains of Hypsizigus marmoreus, 2 strains of Lyophyllum decastes, and 1 strain of Lyophyllum shimeji were used. Monokaryon spores from one variety of H. marmoreus were irradiated with 50~2,000 Gy of gamma ray. The propriety dose was 50~200 Gy for mutagenesis. Mutant monokaryon mycelia crossed each order to become dikaryon mycelia. The internal transcribed spacer (ITS) regions of rDNA were amplified using PCR, and the products were sequenced. The sequences of the ITS regions (16 partial rDNA, complete ITS1, 5.8 rDNA and partial rDNA) were analyzed by PCR, and strains of H. marmoreus, L. decastes, and L. shimeji were auto-sequenced. The lengths of the sequenced ITSs were 1,052~1,143 nucleotides. Genetic matrices were calculated using Nei-Li's genetic distance coefficient based on ITS sequence. The dissimilarities were 0~3.35% in strains of H. Hypsizigus. In addition, a phylogenetic tree was constructed based on ITS sequences using the neighbor-joining (NJ) method. The phylogenetic tree revealed that 23 strains and 5 mutant groups were divided into 12 clusters; the mutant groups fell into different clusters. These results show that mushroom spores were mutated effectively by gamma ray; therefore, gamma ray could be a useful tool for breeding new strains of mushrooms.

• The Korean Journal of Mycology
• /
• v.27 no.5 s.92
• /
• pp.322-327
• /
• 1999

Five white fruitbodies of Ganoderma lucidum found from two different mushroom farms, and the characteristics of atypical fruiting structure formation of these strains were described. The white fruitbodies were spontaneously generated on Quercus-log during the cultivation. They did not differentiate to the normal fruitbodies with pileus, hymenium, stipe and coloration, and fruitbodies remained non-laccateed even after 3 months. Dikaryotic mycelia isolated from the five white fruitbodies differed from wild-type strains in the mycelial growth rate, colony color, and the capacity of atypical fruiting structure (AFS) formation on agar media. These white mutants readily induced brown colored AFSs on the colonies under ventilation and illumination conditions. Both isolates Gl-010 and Gl-011 that were obtained from a normal and white fruitbody, respectively, did not form AFSs in the dark and/or under black light blue (BLB) light illumination, but induced under the visible light. They required dim light for the AFS formation, and the AFS formation was inhibited up to $0.5{\mu}mol\;m^{-2}\;S^{-1}$ in light intensity. However, the other four isolates induced AFSs even in the dark and BLB illumination, although their parent strain, isolate Gl-030, did not form AFSs under any light conditions. The monokaryotic mycelia derived from basidiospores of the AFSs of the white mutants were compatible with the original culture (dikaryon) on a dual culture.

• Journal of Mushroom
• /
• v.5 no.1
• /
• pp.1-6
• /
• 2007

A new commercial strain "Hambak" of Grifola frondosa was developed by di-mono crossing between dikaryon of ASI 9031 and monokaryotic strain derived from ASI 9021. It can be cultivated in plastic bottle and bag filled with oak and poplar sawdust substrate which supplemented with 15% rice bran or 10% corn bran. Improvement of cultivation methods was required for shortage of mycelium incubation period and management of humidity in growing room. The optimum temperature of mycelial growth was $25^{\circ}C$ and that of fruiting body development was $15{\sim}18^{\circ}C$. The color of pileus surface was brown and fine pores, whitish to cream-colored, were underside. Primordia formation of Hambak was two days faster than that of Yipsae 1. The yield was $97g/850m{\ell}$ bottle, a bunch of fruiting body was bigger and the quality was better than Yipsae 1.