• Journal of Environmental Science International
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• v.14 no.4
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• pp.389-395
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• 2005

The changes of O-J-I-P transients were investigated using leaves of four subtropical plant species (Crinum asiaticum var. japonicum, Osmanthus insularis, Chloranthus glaber and Asplenium antiquum) under the natural conditions in winter, in order to select the stress indicators for diagnosing physiological states of plants under low temperature. In the O-J-I-P transients of these species, the fluorescence intensity was found to be higher in O-step and lower in P-step in winter than in summer. Particularly, the fluorescence intensity of the P-step in Crinum asiaticum var. japonicum was lower than those of other three plant species, indicating that Crinum asiaticum var. japonicum is the most sensitive to low temperature. Of the chlorophyll fluorescence parameters derived from O-J-I-P transients of four subtropical plants, Fm, Fv/Fo, ABS/CS, TRo/CS, $\phi_{po}$ and $\phi_{po}/(1-\phi_{po})$ decreased significantly with the increase of Fo, Sm, N, EToICS, ETo/RC and $\psi_o/(1-\psi_o)$ depending on temperature drop in winter. Therefore, these parameters could be used as indicators for estimating low temperature stress and diagnosing physiological states of plants under the natural conditions in winter.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.485-491
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• 2015

This study was conducted to develop stem volume models for the volume estimation of Quercus glauca Thunb. in Jeju Island, Republic of Korea. Furthermore, this study validated the developed stem volume models using an independent dataset. A total of 167 trees were measured for their diameter at breast height (DBH), total height and stem volume using non-destructive sampling methods. Eighty percent of the dataset was used for the initial model development while the remaining 20% was used for model validation. The performance of the different models was evaluated using the following fit statistics: standard error of estimate (SEE), mean bias absolute mean deviation (AMD), coefficient of determination (R²), and root mean square error (RMSE). The AMD of the five models from the different DBH classes were determined using the validation dataset. Model 5 (V = aD^bH^c), which estimates volume using DBH and total height as predicting variables, had the best SEE (0.02745), AMD (0.01538), R² (0.97603) and RMSE (0.02746). Overall, volume models with two independent variables (DBH and total height) performed better than those with only one (DBH) based on the model evaluation and validation. The models developed in this study can provide forest managers with accurate estimations for the stem volumes of Quercus glauca in the subtropical forests of Jeju Island, Korea.

• Journal of Environmental Science International
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• v.22 no.1
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• pp.99-107
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• 2013

This study surveyed the distribution and characteristics of epiphytes and host trees in Jejudo's warm-temperate evergreen forests area. The gathered data will be used for evaluating ecological changes according to climate change. The study found 46 species of epiphytes in Jejudo; 12 of which were species of pteridophytes and 5 species of orchids, totaling 17 species of epiphytes. The appearance frequency was the greatest with Lepisorus thunbergianus, followed by Lemmaphyllum microphyllum and Lepisorus onoei. The area with the greatest diversity of epiphytes was nutmeg tree forests which have the largest number of 2.89 average species. Lemmaphyllum microphyllum had the greatest percent cover of the epiphytes whose importance was found to be the greatest. The factors involved were the epiphytes' diversity index (0.64), maximum species diversity (1.23), evenness (0.52), and dominance (0.48). The study has noted the distribution characteristics of epiphytes according to altitudes above sea level. The Lemmaphyllum microphyllum can survive at an altitude of 600 m above sea level, Lepisorus thunbergianus at 200 - 1,400m above sea level, Lepisorus onoei. at 400 - 1,000 m, and Gonocormus minutus at an altitude above 800 m. The host trees, consisting of Quercus serrata, Castanopsis cuspidata var. sieboldii, and Carpinus laxiflora, stands at 2-19 m high and 2.5 - 120 cm wide, showing diverse kinds of trees and sizes. Jejudo's warm-temperate evergreen forests have lower epiphyte diversity compared with those of subtropical and tropical areas in Japan and China. Based on the characteristics of the host trees order, epiphytes' distribution associated with the altitude above sea level was typical.

• Journal of the Korean earth science society
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• v.35 no.1
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• pp.88-94
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• 2014

The seasonal predictability of the intensity of the Northeast Asian summer monsoon is low while that of the western North subtropical high variability is, when state-of-the-art general circulation models are used, relatively high. The western North Pacific subtropical high dominates the climate anomalies in the western North Pacific-East Asian region. This study discusses the predictability of the western North Pacific subtropical High variability in the National Centers for Environmental Prediction Climate Forecast System (NCEP CFS). The interannual variability of the Northeast Asian summer monsoon is highly correlated with one of the western North Pacific subtropical Highs. Based on this relationship, we suggest a seasonal prediction model using NCEP CFS and canonical correlation analysis for Northeast Asian summer precipitation anomalies and assess the predictability of the prediction model. This methodology provides significant skill in the seasonal prediction of the Northeast Asian summer rainfall anomalies.

• Korean Journal of Agricultural Science
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• v.41 no.3
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• pp.187-191
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• 2014

The cultivation area and use of genetically modified (GM) crops have been increased continuously over the world. Concerns about the potential risks of GM crops are also increasing. Safe management for the development and production of GM crops is required according to Living Modified Organism Act in Korea. Planning about the methods, duration, and frequency of environmental monitoring is also required for commercial use of GM crops. GM Zoysia japonica Steud. (event name: JG21) expressing resistance to glufosinate-ammonium has been generated previously. By using gamma ray treatment to JG21 we also developed male sterility and dwarf Z. japonica (event name: JG21-MS). The objective of this study was to establish the monitoring system for environment release of JG21-MS. In this study we extracted RNA from JG21 and JG21-MS and conducted RAPD (random amplified polymorphic DNA) method to distinguish JG21 and JG21-MS.

• Plant Biotechnology Reports
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• v.3 no.3
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• pp.191-197
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• 2009

Four-leaf white clover is not found easily in nature due to its low appearance rate (1 in 10,000). Because people believe that it brings good luck and like to either keep it or present it to a loved one, it has commercial and ornamental value. To breed four-leaf clover, we exposed its flowers to ${\gamma}-rays$ at the pollination stage. The $M_1$ seeds produced following doses at 25-100 Gy showed an approximately 74% germination rate, with seedling survival at 46%. In the $M_1$ generation of plants irradiated within that dose range, we found an increased frequency of four leaflets. One of them, Jeju Lucky-1 (JL-1), had a frequency of about 60%. To see whether that mutation was somaclonal or genetic, we observed its $M_2$ generation and found that such a phenotype reappeared. Although our results demonstrated that the irradiation of fully mature flowers led to a higher frequency of 4-leaflets, we could not clearly explain the genetic mechanism involved. We suggest that JL-1 is valuable as a new variety, without further genetic fixation, because white clover can be propagated vegetatively by stolons.

• Journal of Veterinary Science
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• v.23 no.4
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• pp.57.1-57.9
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• 2022

Background: Classical swine fever virus (CSFV), the causative agent of classical swine fever (CFS), is a highly contagious disease that poses a serious threat to Chinese pig populations. Objectives: Many provinces of China, such as Shandong, Henan, Hebei, Heilongjiang, and Liaoning provinces, have reported epidemics of CSFV, while the references to the epidemic of CSFV in Yunnan province are rare. This study examined the epidemic characteristics of the CSFV in Yunnan province. Methods: In this study, 326 tissue samples were collected from different regions in Yunnan province from 2015 to 2021. A reverse transcription-polymerase chain reaction (RT-PCR), sequences analysis, and phylogenetic analysis were performed for the pathogenic detection and analysis of these 326 clinical specimens. Results: Approximately 3.37% (11/326) of specimens tested positive for the CSFV by RT-PCR, which is lower than that of other regions of China. Sequence analysis of the partial E2 sequences of eleven CSFV strains showed that they shared 89.0-100.0% nucleotide (nt) and 95.0-100.0% amino acid (aa) homology, respectively. Phylogenetic analysis showed that these novel isolates belonged to the subgenotypes 2.1c and 2.1d, with subgenotype 2.1c being predominant. Conclusions: The CSFV was sporadic in China's Yunnan province from 2015 to 2021. Both 2.1c and 2.1d subgenotypes were found in this region, but 2.1c was dominant.

• Journal of Life Science
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• v.28 no.7
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• pp.795-801
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• 2018

This study was conducted to investigate the association of single nucleotide polymorphism (SNP) markers on equine chromosomes (ECA) 3 and 9 with body weight in Jeju horses. We used DNA samples and body weight data of 320 horses provided by the Livestock Promotion Agency, Jeju Special Self-Governing Province, and the Korean Racing Association, respectively. We genotyped all the experimental animals using nine SNP markers located on ECA 3 (BIEC2-808466, BIEC2-808543, BIEC2-808967, and BIEC2-809370) and ECA 9 (BIEC2-1105370, BIEC2-1105372, BIEC2-1105377, BIEC21105505, and BIEC2-1105840). These markers were selected due to their effects on body conformation traits in horses. The joint effect of the genotypes of the two SNP markers (BIEC2-808467 and BIEC2-1105377) regarding body weight were also evaluated. The estimated breeding value (EBV) of body weight was obtained as the dependent variable for association analyses using a linear mixed model. Significant associations were detected between SNP markers (BIEC2-808543, BIEC2-808967, BIEC2-809370, BIEC2-1105370, BIEC2-1105372, and BIEC2-1105377) and the body weight EBV. In addition, the joint genotype effect of the BIEC2-808467 and BIEC2-1105377 on the body weight EBV was significant. These results indicate that the SNP markers, which showed their significant effects on body conformation, can be used as genetic markers to improve the efficiency of the selective breeding program for the body weight traits in Jeju horses.

• Journal of Animal Science and Technology
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• v.46 no.6
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• pp.917-924
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• 2004

Using PCR-RFLP haplotyping for the mitochondrial DNA(mtDNA) fragment containing the NADH dehydrogenase 2 gene(ND2) and three tRNA genes(tRNA-Met, tRNA-Trp and tRNA-Ala), we characterized the genetic diversity of five pig breeds including Jeju native pigs. mtDNA polymorphisms showing distinct cleavage patterns were found in the pig breeds. Two digestion patterns were detected when HaeIII- and Hinfl-RFLP, and four in the Tsp5091-RFLP analyses. Combining the three restriction enzyme digestion patterns found in five different pig breeds, four mtDNA haplotypes were observed and the haplotype frequencies were significantly different by the pig breeds. A monomorphic haplotype, mtWB, was observed in both Korean wild boars and Large White pigs. Both Duroc and Landrace pigs contained two haplotypes suggesting their multiple maternal lineages. Jeju native pig has two haplotypes(mtJN and mtJD). Of these, mtJN is identified as a Jeju native pig specific haplotype. This study suggested that more than two progenitor populations have been taken part in the domestication process of the Jeju native pig population, and/or probably subsequent crossing with other pig breeds from near east Asia. Unlike with our prediction, there was no direct evidence under molecular levels on the maternal introgression of Korean wild boar in the domestication of Jeju native pigs. In conclusion, specificity of mtDNA haplotypes related to pig breeds win be useful for identifying the maternal lineage as wen as constructing the genealogical pedigree in pigs.

• The Korean Journal of Malacology
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• v.18 no.1
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• pp.27-40
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• 2002

Beach death assemblages of bivalve mollusks were studied with respect to their species composition in six localities along the eastern coast of Korea (Gangneung, Jumunjin, Daejin, Gallam, Jukbyeon, Hupo and Chooksan). In all, thirty-nine species belonging to 30 genera and 19 families were recorded, and species diversity between the sampling sites varied from 5 to 21. Biogeographical analysis showed that studied fauna has warm-water character with the predominance of subtropical and subtropical-lowboreal species and the presence of tropical-subtropical species (in total, 77 %), and only 23 % of mollusks found are cold-water and temperate species. The most abundant species were Septifer virgatus (Wiegmann, 1837), Mytilus galloprovinciallis Lamarck, 1819, Gomphina melanaegis Romer, 1861, Ruditapes philippinarum (Adams et Reeve, 1850), Mactra chinensis Philippi, 1847 and Spisula sachalinensis (Schrenck, 1862).