• Journal of Life Science
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• v.13 no.2
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• pp.191-196
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• 2003

The ars gene of the Neurospora crassa encodes arylsulfatase and is expressed under sulfur limitation. An ars-1 promoter(Pars) translationally-fused to a lacZ gene was transformed into the N. crassa RLM 35-35, a his-3 inl strain and integrated into the his-S locus by a single crossover homologous recombination. $\beta$-galactosidase specific activity was measured from mycelia grown in sulfur-limited Vogel's medium. Enzyme activity reached its maximum at 14 hour after the shift to derepressing condition. When activity from homokaryon generated by microconidiation was measured, it was 17% a higher than that from heterokaryon.

• Korean journal of applied entomology
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• v.5_6
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• pp.19-26
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• 1968

Results obtained from the observation of 1,000 matured resting conidia of Pyricularia oryzae CAV. were as fellows. The percentage of a condium conitaining was 95.5, while that of a multinucleate conidium was 4.5. Formation of the three-celled mature conidium containing a nucleus in each cell, which was derived from the immatured conidium, could be recognized. Chromosomes could be observed in the conidium when the nuclear division took place. The number of chromosomes was n=3, 4, 5 or 6 but rile majority was 5. The nucleus was moved into the germ-tube from the conidium by following ways: (a) a resting nucleus divided into two nuclei in the conidium and one of them was moved into the germ-tube. The other nucleus remained in the conidium (43 per cent): (b) a nucleus was moved into the germ-tube from the conidium without nuclear division (57 Per cent). The appressorium without a nucleus was abundantly observed when stain was made. However, tile number of a mononucleate appressorium was 476 out of 500 appressoria which had nuclear sap. On the ground of this experiment, we could support the conidium of blast fungus contained mononucleus and also homokaryon seemed to b: appealed on the conidia even though those were multilocular. As the results, it could be concluded that use of inoculum derived from single spore isolate was reasonable for any experiments in the rice blast fungus.

• The Korean Journal of Mycology
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• v.44 no.2
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• pp.94-99
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• 2016

Since development of the first Korean button mushroom cultivar 'Sae-Ah' in 2010, mushroom farmers have demanded an improved cultivar. Although a new cultivar, 'Saejeong', was developed in 2011, this cultivar has thus far been difficult to cultivate in typical mushroom farms. To solve this problem, another new cultivar, 'Saedo', was developed in 2012. This new cultivar was selected by genetic analysis from crossing the heterokaryon line A175 and the homokaryon line ASI1346-15. The heterokaryon A175 was a crossed line between strains ASI1038-211 and ASI1346-20. The mycelium of 'Saedo' showed good growth on compost dextrose agar at $25^{\circ}C$. The morphological traits such as the pileus (cap) and stipe of the 'Saedo' cultivar were thicker than those of the reference control 'Saejeong', and the production yield was increased by 1.89-fold compared to that of the reference control. A field experiment of the 'Saedo' cultivar has been ongoing since 2013. The yield of the 'Saedo' cultivar was found to be substantially higher than that of the reference control during the $2^{nd}$ flush.

• Journal of Microbiology and Biotechnology
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• v.20 no.4
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• pp.683-692
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• 2010

Morphologically, nine different slow-growing protoclones were screened from regenerated protoplasts of heterokaryotic Agaricus bisporus. As such, the present study is the first report on differentiating homo- and heterokaryotic protoclones using random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) markers. Among 80 primers tested, the seven ISSR and seven RAPD primers selected for the analysis generated a total of 94 ISSR and 52 RAPD fragments, respectively. The ISSR fingerprinting also detected more polymorphic loci (38.29%) than the RAPD fingerprinting (34.61%). A principal coordinate analysis (PCA) was employed to evaluate the resolving power of the markers as regards differentiating protoclones. As a result, the mean polymorphism information content (PIC) for each marker system (i.e., 0.787 for RAPD and 0.916 for ISSR) suggested that ISSR is more effective for determining polymorphisms. The dendrograms constructed using RAPD, ISSR, and an integrated RAPD and ISSR marker system were highly correlated with one another as revealed by a high Mantel correlation (r= 0.98). The pairwise similarity index values also ranged from 0.64 to 0.95 (RAPD), 0.67 to 0.98 (ISSR), and 0.67 to 0.98 (RAPD and ISSR), whereas the mean similarity index values of 0.82, 0.81, and 0.84 were obtained for the RAPD, ISSR, and combined data, respectively. As there was a good correspondence between the RAPD and ISSR similarity matrices, ISSR would appear to be an effective alternative to RAPD in the genetic diversity assessment and accurate differentiation of homo- and heterokaryotic protoclones of A. bisporus.

• Journal of Mushroom
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• v.13 no.3
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• pp.175-180
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• 2015

Twenty Inter simple sequence repeat (ISSR) primers were used to assess genetic diversity of 64 Agaricus strains including 45 A. bisporus strains and other 19 Agaricus spp. ISSR primers, (GA)T, (AG)YC, (GA)C and (CTC) amplified PCR polymorphic bands between the Agaricus species or within A. bisporus strains. PCR polymorphic bands were inputted for UPGMA cluster analysis. 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 0.92, whereas, other Korean strains were genetically related to A. bisporus strains that were introduced from USA, Eroupe and Chinese. Furthermore, ISSR-PCR polymorphism could potentially be used to identify homokaryon isolates.

• Journal of Mushroom
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• v.12 no.2
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• pp.82-87
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• 2014

Commonly known as the button mushroom, Agaricus bisporus is one of the most widely cultivated mushroom species of edible fungi. In the breeding of new button mushroom, Seolwon was developed by crossing two homokaryons. Because of the predominantly pseudohomothallic life cycle, only a small percentage of homokaryotic meiospores are produced, which do not fruit. Homokaryotic cultures derived from these types of single spores produce a vegetative mycelium that contain a variable number of genetically identical nuclei per cell. After crossing two homokaryons, hybrids were cultivated on a small scale and on a commercial scale at a farm. The spawn was made by a commercial spawn producer and the spawned compost by a commercial compost producer. Mycelial growth of Seolwon on CDA was better at $25^{\circ}C$ when it was compared with that of Seolgang. The mature cap shape of new strain Seolwon is oblate spheroid and the immature cap shape is round to oblate spheroid. The cap diameter was 39.7 mm on average. In comparison with white strain Seolgang, the strain had a yield that was 11% higher. It produced fruiting bodies which had a higher weight on average per fruiting body and were 9.7% firmer with a good shelf life. Days of fruiting body were 1-2 days later than those of Seolgang. The physical characteristics such as springiness, chewiness, adhesiveness, gumminess were better than that of Seolgang.

• 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.

• Journal of Mushroom
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• v.13 no.3
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• pp.243-249
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• 2015

Agaricus bitorquis is an edible white mushroom of the genus that is cultivated at high temperature($25{\pm}1^{\circ}C$) unlike A. bisporus is cultivate at $16{\pm}2^{\circ}C$. Unlike Agaricus bisporus, an edible white A. bitorquis mushroom is cultivated at high temperature ($25{\pm}1^{\circ}C$). Most farmers cultivate this mushroom for a long cultivation period in Korea. For this reason, we made heterokayons to develop a new cultivar that generate fruitbodies for short cultivation period. Over one hundred SSIs(single spores isolates) were collected from selected A. bitorquis ASI1151 and ASI1349 strains. Seventy-three SSIs were germinated on CDA(compost dextrose agar) media after 20 days (minimum) or 83 days (maximum) incubation under different media condition. The mycelial growth rate of germinated SSIs was different. 9 homokaryons in ASI 1151 and 11 homokaryons in ASI 1349 from SSIs were selected by OPN-02 primer in RAPD analaysis. Also this primer was used to select heterokaryon that cross among each homokaryon with compatible locus. Therefore 44 compatible matings were confirmed of 99 crossed lines.