• Korean Journal of Comparative Education
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• v.28 no.1
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• pp.1-24
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• 2018

The objective of the article is to find the research trends and the main traits presented in the keywords on abstracts of research articles of "International Journal of Education Development" from 2002 to 2017. To do this, Text Network Analysis(TNA) was applied targeting 966 papers on the journal and the major research outcomes are as follows. First, the frequency analysis on the keywords showed that the keywords like Administration of education program, Schools and instruction, Regional public administration, Educational support service, Elementary education, and Elementary and secondary school were analyzed more than 100 times and also high in centrality degree. Second, the analysis results of the keywords presented in those research articles by development goal periods showed that several new keywords like Elementary education, Elementary and secondary school, Education quality, Secondary education, Educational planning have emerged frequently after SDGs and these keywords showed high in their centrality analysis. Third, the analysis on education level showed that the keywords like Elementary education, Administration of education program, School children were high in frequency and centrality degree in Elementary level. In secondary level, Schools and instruction, Administration of education program, Academic achievement were high, and in high level, college and university was high, respectively.

• Genes and Genomics
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• v.40 no.12
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• pp.1373-1382
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• 2018

Hanwoo and Chikso are classified as Korean native cattle breeds that are currently registered with the Food and Agriculture Organization. However, there is still a lack of genomic studies to compare Hanwoo to Chikso populations. The objective of this study was to perform genome-wide analysis of Hanwoo and Chikso populations, investigating the genetic relationships between these two populations. We genotyped a total of 319 cattle including 214 Hanwoo and 105 Chikso sampled from Gangwon Province Livestock Technology Research Institute, using the Illumina Bovine SNP50K Beadchip. After performing quality control on the initially generated datasets, we assessed linkage disequilibrium patterns for all the possible SNP pairs within 1 Mb apart. Overall, average $r^2$ values in Hanwoo (0.048) were lower than Chikso (0.074) population. The genetic relationship between the populations was further assured by the principal component analysis, exhibiting clear clusters in each of the Hanwoo and Chikso populations, respectively. Overall heterozygosity for Hanwoo (0.359) was slightly higher than Chikso (0.345) and inbreeding coefficient was also a bit higher in Hanwoo (-0.015) than Chikso (-0.035). The average $F_{ST}$ value was 0.036 between Hanwoo and Chikso, indicating little genetic differentiation between those two breeds. Furthermore, we found potential selection signatures including LRP1B and NTRK2 genes that might be implicated with meat and reproductive traits in cattle. In this study, the results showed that both Hanwoo and Chikso populations were not under severe level of inbreeding. Although the principal component analysis exhibited clear clusters in each of the populations, we did not see any clear evidence that those two populations are highly differentiated each other.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.2
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• pp.102-108
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• 2019

Pericarp thickness of vegetable corns such as sweet and waxy corn is one of the crucial traits, contributing to their edible quality. This study was carried out to compare the pericarp thickness of super sweet and waxy corn hybrids measured with kernel samples prepared using different methods at different grain filling periods. The samples comprised excised pericarp from dried, frozen (at $-4^{\circ}C$), and fresh kernels. Analysis of variance performed separately on super sweet and waxy corn hybrids indicated a significant three-way interaction among cultivars, kernel sample preparation methods, and days after pollination (DAP). Dried samples of super sweet corn hybrids presented reasonably stable pericarp thickness measurements during grain filling, while all the sample preparation methods fluctuated less as grains of waxy corn hybrids matured. Waxy corn is best consumed at around 24 days after pollination. Pericarp thickness of waxy kernel samples regardless of preparation methods investigated was the same at 24 DAP with a few exceptions. Overall, the common method of drying kernel samples before pericarp excision can provide reliable data for estimating the tenderness of vegetable corn hybrids.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.364-377
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• 2018

Hexaploid wheat (common wheat/bread wheat) is one of the most important cereal crops in the world and a model for research of an allopolyploid plant with a large, highly repetitive genome. In the heritability of agronomic traits, variation in gene presence/absence plays an important role. However, there have been relatively few studies on the variation in gene presence/absence in crop species, including common wheat. Recently, a reference genome sequence of common wheat has been fully annotated and published. In addition, advanced next-generation sequencing (NGS) technology provides high quality genome sequences with continually decreasing NGS prices, thereby dawning full-scale wheat functional genomic studies in other crops as well as common wheat, in spite of their large and complex genomes. In this review, we provide information about the available tools and methodologies for wheat functional genomics research supported by NGS technology. The use of the NGS and functional genomics technology is expected to be a powerful strategy to select elite lines for a number of germplasms.

• Korean Journal of Plant Resources
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• v.34 no.5
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• pp.443-450
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• 2021

Peach flesh color is commercially important criteria for classification and has implications for nutritional quality. To breed new yellow-fleshed peach cultivar many cross seedlings and generations should be maintained. Therefore it is necessary to develop early selection molecular markers for screening cross seedlings and germplasm with economically important traits to increase breeding efficiency. For the comparison of transcription profiles in peach varieties with a different flesh color expression, two cDNA libraries were constructed. Differences in gene expression between yellow-fleshed peach cultivar, 'Changhowon Hwangdo' and white-fleshed peach cultivar, 'Mibaekdo' were analyzed by next-generation sequencing (NGS). Expressed sequence tag (EST) of clones from the two varieties was selected for nucleotide sequence determination and homology searches. Putative single nucleotide polymorphisms (SNPs) were screened from peach EST contigs by high resolution melting (HRM) analysis, SNP ID ppa002847m:cds and ppa002540m:cds displayed specific difference between 17 yellow-fleshed and 21 white-fleshed peach varieties. The SNP markers for distinguishing yellow and white fleshed peach varieties by HRM analysis offers the opportunity to use early selection. This SNP markers could be useful for marker assisted breeding and provide a good reference for relevant research on molecular mechanisms of color variation in peach varieties.

• Korean Journal of Plant Resources
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• v.34 no.1
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• pp.79-88
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• 2021

This research was conducted to investigate the genetic diversity and select useful accession with agronomic characteristics of garlic (Allium sativum L.). germplasms at Garlic Research Institute in Chungbuk Agricultural Research and Extension Service. Morphological diversity and relationships among 160 germplasms collected from 26 countries were assessed by methods of clustering and principal component analysis. Among 11 types of leaves and bulbs characteristics, emergence days of leaf showed the highest variation with coefficient of variation of 84.8%, and the bulb weight and the number of scales showed higher variability with 24.3%. Correlation analysis based on 11 quantitative traits showed that bulb weight and bulb length have very high positive correlation with bulb quantity. Plant height, leaf length, and number of leaves showed positive correlation with bulb weight as collections with better performance in growth produced large bulb with higher quality. The cluster analysis based on 5 principal components generated 6 clusters with an average distance of 1.6 among clusters. Domestic genetic resources were the largest with 36 species (22.5%) in group II.

• Journal of Life Science
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• v.32 no.4
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• pp.279-284
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• 2022

This study was conducted to establish a genetic evaluation system applicable to general farms for improving cows raised on farms. The analysis used Best Linear Unbiased Prediction (BLUP) and Genomic Best Linear Unbiased Prediction (GBLUP) for 619 cows raised in Gyeonggi-do Province and compared and analyzed the accuracy of the estimated breeding value according to four traits (carcass weight, loineye muscle area, back fat thickness, and marbling). In the case of the GBLUP method, the size of the reference population was divided into different four groups and analyzed. The analysis results confirmed that the accuracy of the breeding value of each trait increased as the size of the GBLUP reference population increased. Comparing the accuracy of the breeding values estimated using the BLUP and GBLUP methods, it was confirmed that when the breeding values were estimated using the GBLUP method, they increased by 0.10, 0.09, 0.09, and 0.11 for carcass weight, eye muscle area, back fat thickness, and marbling scores, respectively. Applying the GBLUP method to the evaluation and selection of cows can enable precise and accurate individual selection, while increasing the size of the reference population can make even more accurate individual selection possible, thus increasing selection efficiency.

• Journal of Mushroom
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• v.19 no.4
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• pp.279-284
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• 2021

Flammulina velutipes is the representative edible mushroom in Korea. It makes up around 18% of the total mushroom production and accounts for about 36% of the total mushroom export. Despite being one of the most industrially important mushroom in Korea, the distribution rate of domestic cultivar was low (~31.6%) in 2020. Therefore, we need a new domestic cultivar with high quality as the main export mushroom. We developed a new white domestic cultivar, 'Seolhan', bred by mating two monokaryotic strains isolated from Baekseung and Woori-1ho. The optimum mycelial growth temperature was 25℃ and Seolhan had higher mycelial growth than the control at 20 and 25℃. In bottle cultivation, the optimum temperature of incubation was from 15℃ to 17℃ and the growth temperature of Seolhan was 7-8℃, which was slightly higher than that of the control. The yield of Seolan was 226.5±8.0 g, an increase of 18.4% compared to the control. The period of primodia formation also was a couple of days ahead. In morphological traits, the pileus of Seolhan was smaller than that of the control, the stipe was thicker, and the color brighter. As the results of replacement culture and genetic diversity test, it was confirmed that Seolhan was genetically different from other white varieties.

• Journal of Marine Life Science
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• v.6 no.2
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• pp.47-57
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• 2021

In the fishery industry, global aquaculture production has stagnated due to overfishing of aquatic products, restrictions between countries, and climate change. The aquaculture suggests the possibility of a blue revolution that can be expanded in a new way. The aquaculture industry now accounts for more than half of the fishery products from the sea as a raw material for seafood for human consumption. Various latest biological research methods are being applied for the development of a sustainable aquaculture industry. Genomics has made significant progress in recent years. Since the genome sequence of Atlantic cod was sequenced in 2011, the genomes of more species have been sequenced. The genome information is providing a more robust and productive knowledge base for the aquaculture industry, including breeding and breeding of superior traits, improving disease resistance quality, and optimizing aquaculture feed and feed methods. This review looked at the status of genome analysis technology and the current status of genome research of aquaculture species. The development of genome research technology and massive genomic information is important in solving the challenges of the aquaculture industry and will help sustainable fisheries and aquaculture.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.91-99
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• 2023

Plus tree selection is the essential first step in a tree improvement program. This study was carried out to select plus trees of black locust (Robinia pseudoacacia L.) for tree improvement in Korea. The candidate plus trees of black locust were selected from twenty-one places in the four provinces (Gangwon, Gyeonggi, Chungcheong and Gyeongsang) following comparison selection. The trees were examined for qualitative and quantitative traits of economic interest like tree height (H), diameter at breast height (DBH), clear bole height (CBH), stem straightness (SS), crown size (CS) and disease resistance. The 64 selected trees showed higher quality in growth characteristics than control trees. Average of height, DBH, CBH, SS and CS were 20.5 m, 31.1 cm, 10.1 m, 1.2 and 5.2 m respectively. In particular, it was shown that the growth characteristics were higher in Chungcheong population. The superiority percentage of selected candidate plus trees of black locust over their respective check trees ranged from 7.3% to 18.9% in height, 20.0% to 40.6% in DBH, 32.8% to 73.5% in CBH, 42.9% to 55.2% in SS and -11.1% to 9.4% in CS, respectively. The selected black locust will be useful in future tree breeding programs based on their clonal and progeny performance.