• Journal of Mushroom
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• v.16 no.1
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• pp.16-21
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• 2018

In order to breed a new Pleurotus eryngii cultivar exhibiting intermediate size and rapid growth, single crosses between $24{\times}46$ and KNR2539 were performed. The resulting new cultivar, $17{\times}15$, was chosen based on the required days to harvest (15.4 days), quality (7.5), and yield (81.5 g/850 cc bottle) obtained in a preliminary test. The strain was named Aeryni 6 and cultivated at mushroom farms on a large scale for comparison with the reference cultivar Kenneutari No. 2. The yield of Aeryni 6 (76.0 g) was 113.0% compared with the reference cultivar, Kenneutari No. 2, and its quality was 6.8, while that of the reference strain was 5.7. An independent t-test revealed significant differences between the days for harvest, yield, and quality of the two cultivars. The new and reference cultivars were discriminated by PCR amplification of URP2 and URP11 and a confrontation cultivation.

• Journal of The Korean Association For Science Education
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• v.29 no.5
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• pp.541-551
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• 2009

This study aimed to investigate the effect of pre-service science teachers' experiences in nuclear physics research on their understanding of scientific inquiry process and career planning. The thirty-week URP (Undergraduate Research Participation) program was designed with the participation of six pre-service science teachers. Data sources included in-depth interviews with the individual teachers, group discussions, participant observations with field notes over the weeks, journals and lab logs, etc. Results indicated that the teachers perceived the complex and repetitive nature of the science research process, the importance of scientists' creativity and collaboration, etc. Their typical impressions of scientists has also more or less changed. In addition, the teachers had opportunities to confirm their aptitude in physics and to explore their career options in physics-related fields.

• Mycobiology
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• v.37 no.3
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• pp.225-229
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• 2009

Single spore isolates of Plasmodiophora brassicae e4 and e9 obtained from diseased Chinese cabbage were identified as race 4 and race 9, respectively, by the Williams' differential variety set. To confirm the possibility of variation in same generation and progeny of a single spore isolate of P. brassicae, random amplified polymorphic DNA (RAPD) analysis was conducted using the URP 3, 6 and OPA 7 primers. There was no difference in band type at each part of the gall of Chinese cabbage obtained by inoculation of e4 and e9 and amplification using the URP 3 and 6 primers when the same generation was analyzed. In addition, the progeny analysis, which was expanded to the third generation and conducted using the URP 3 and OPA 7 primers, revealed no differences in the band type of the e4 isolate. Based on these results, the single spore isolate of P. brassicae was genetically stable.

• Journal of The Korean Association For Science Education
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• v.38 no.3
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• pp.343-354
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• 2018

In this study, the first experience of the whole research process of a novice scientist (student A) who participated in the Undergraduate Research Program (URP) was analyzed. The data were collected through observation, interviews, and document analysis with the cultural historical activity theory being used as a theoretical lens. At the beginning of novice's research, the mentor guided him in setting a research goal and provided mediating artifacts. Student A formed a research team based on the vertical relationship without a shared mental model. Two major contradictions occurred and they were the sources of changes of student A's activity system. The first contradiction was between the mentor's educational philosophy and the mentee's educational needs, which was resolved in a way that student A asked and used the mentor's network to obtain his needs about task-specific details. The second contradiction arose because the team members wanted horizontal relationship while student A wanted to stick to the vertical relationship. After student A accepted the opinions of the team members, they cooperatively changed the division of labor in the activity system. Student A decided to become a scientist and not a physics teacher, even if his major is physics education after finishing his URP research process. His URP experience also created and expanded his network in the academic field, and his negative attitude toward collaboration changed positively. Through the analysis of the structure and changes in the activity system of URP research, implications for instructional method and support system of the apprenticeship can be obtained.

• The Korean Journal of Mycology
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• v.31 no.2
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• pp.103-113
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• 2003

Twenty five isolates of Alternaria were obtained from various solanaceous crops in Korea. For all isolates, morphological characteristics of the conidia were determined and compared with those of representative isolates of A. solani and A. tomatophila. A selection of the isolates and the representative Alternaria isolates were evaluated for Pathogenicity to potato, tomato, egg plant and red pepper. Molecular characteristics of 17 isolates of Alternaria inculding the representative isolates were determined using sequence analysis of IRS rDNA and histone H3 gene, and URP-PCR analysis. Based on morphological characteristics, the isolates from the solanaceous crops were grouped as identical or very similar to either A. tomatophila (ATO), A. solani (ASO), and unidentified Alternaria sp. (ASP). Isolates of ASO were moderately pathogenic to all the solanaceous crops tested, but ATO isolates were highly pathogenic to tomato and the ASP isolate was pathogenic only to potato. Among the molecular markers used in this study, the URP-PCR analysis was found to be appropriate for taxonomic resolution of these species. Based on the conidial morphology, pathogenicity test and molecular characteristics, A. tomatophila (early blight of tomato) could be distinguished from A. solani (early blight of potato), and the Alternaria sp. (ASP) from potato, which was closely related to ASO in conidial morphology, was considered as a new species.

• Proceedings of the Korean Society of Applied Entomolohy Conference
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• 2000.05a
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• pp.132-132
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• 2000

• Journal of Mushroom
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• v.13 no.2
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• pp.135-138
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• 2015

'Daejang 3ho' is a new cultivar of oyster mushroom for high productivity than that of Chunchu 2ho. This cultivar was bred by Di-mon mating between monokaryotic strains isolated from 'Daejang 1ho' and dikaryotic strain 'Jangan 5ho'. The color of pileus and the shape of pileus of new cultivar were dark gray and deeply funnel shape, respectively. The length and thickness of stipe were longer and thicker than those of Chunchu 2ho. It took 4~5 days to formation of primordia, that was a similar to Chunchu 2ho. The optical temperature of fruit body was $14-17^{\circ}C$. Yield of 'Daejang 3ho' was 13.9% higher than that of Chunchu 2ho. Analysis of RAPD by URP-primer of #03, #08, #10 and #11 showed that different band pattern those of other strains. There were no significant differences between the texture properties of 'Daejang 3ho' and Chunchu 2ho.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.313-323
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• 2020

To investigate the morphological characteristics and genetic relationships among isolate of the artificially cultivated mushroom Hypsizygus marmoreus, 111 isolates were collected from Korea and other countries. Random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR) and ITS rDNA sequencing were used to confirm the genetic relationships among the collected H. marmoreus isolates. As a result of RAPD analysis using universal rice primer (URP)-PCR, all isolates of H. marmoreus clustered into three groups, which showed high sequence similarity (>90%). In addition, isolates with morphological and geographical differences formed independent clusters. However, it was impossible to distinguish between brown and white strains. Sixteen strains showing morphological and geographic differences were selected, and their ITS region sequences (640 bp) were aligned and compared. The ITS region sequences belonging to these isolates showed 94.8-99.1% similarities to those of publicly available H. marmoreus strains in GenBank. In conclusion, there were differences among isolates in terms of morphology and the area from which they were collected, but all the isolates used in the experiment were classified as H. marmoreus.

• Journal of Mushroom
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• v.10 no.3
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• pp.109-114
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• 2012

To develop new variety of oyster mushroom, 63 intra-specific hybrids between the strain Suhan and #Nongi201 were developed using hyphal anastomosis technique in 2004. The Po2008-275 hybrid between the dikaryon strain 04-154(Suhan x #Nongi201) and the monokaryon strain derived from ASI2487 were developed using hyphal anastomosis in 2008. The Po2008-275 was shown the best cultural characteristics, selected to be a new variety and named as 'Guseol'. The new commercial strain, 'Guseol' had dark grey pilei and grows well under spring and autumn conditions in Korea. The fruiting bodies of 'Guseol' were of an excellent quality in that not only the stipe was thick and long but also the pileus was small and hard. The optimum temperatures for mycelial growth and fruiting body development were $25{\sim}30^{\circ}C$ and $10{\sim}16^{\circ}C$, respectively. Time period required for the initiation of the first fruiting body was about 3 to 5 days depending on the temperatures. The shape of fruiting body was thin funnel shape. Fruiting body production per box($43{\times}43{\times}12cm$) was about $1545{\pm}400.9g$ which was almost 137% quantity compared to that of parental strain 04-154. Relatively low temperature incubation ($11^{\circ}C$) resulted in the development of better quality of 'Guseol' mushrooms. When two different media including potato dextrose medium and mushroom complete medium were compared, the mycelial growth of this mushroom were much faster in mushroom complete medium. Similar results were observed with other variety '#Chunchu2'. Analysis of the genetic characteristics of the new commercial strain 'Guseol' showed a major DNA profile as that of the parental 04-154 when primer URP 1, primer URP 2 and primer URP 5 were used, but different to '#Chunchu2' that was used as a control. This new variety of the dark grey oyster mushroom had smart and high quality image that corresponds well to "health food". We therefore expect that this new strain will satisfy the consumers demand for variety and excellent mushrooms.

• Korean Journal of Medicinal Crop Science
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• v.11 no.5
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• pp.377-384
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• 2003

Genetic differences among nine land races of Korean ginseng (Panax ginseng C. A. Meyer) were examined using RAPD markers. Land races of Korean ginseng were collected from nine regions in Korea: Cheongwon, Guesan, Geumsan, Namwon, Pochun, Yangju, Yeoncheon, Yeongju. Out of 48 RAPD primers tested, 5 primers (OPA 7, OPA 13, URP 2, URP 3 and UBC 3) produced remarkable bands which showing polymorphisms among evaluated collections. Lower levels of genetic diversity were in detected same land races than among other land races. Genetic differences within and among land races indicate heterogeneity. These results indicate that cultivated ginseng in Korea is heterogeneous. Genetic similarity matrices of RAPD profiles were generated via coefficients of variation and the data were processed by the cluster analysis (UPGMA). When 90 collections were evaluated using selected 5 primers, those were clustered to 5 and 3 subgroups. These differences in genetic variation between land races of Korean ginseng implied the potential source for further breeding of Korean ginseng.