• The Korean Journal of Mycology
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• v.37 no.1
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• pp.19-27
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• 2009

This study was conducted to investigate genetic characteristics of 25 Pleurotus eringii strains that have been released in Korea based on cultural, morphological features and PCR fingerprints. Strains PER-007 and PER-012 showed distinct cultural characteristics in growth rate, morphological characteristics of mycelial colony and fruiting bodies when compared to those of other strains. Strain PER-007 did not form primordium initiation in sawdust medium and PER-012 also showed different phenotypes on fruiting bodies. Eleven URP primers were used to detect PCR polymophic bands in P. eringii strains. Primers URP1F, URP2R, URP2F, URP4R, URP6R, URP9F and URP17R were selected as useful primers for amplifying PCR polymorphic bands in P. eringii strains. The genetic similarity index was calculated by using PCR polymorphic bands amplified by eight URP primers among the 25 strains. The P. eringii strains were grouped by four distinct clusters on the UPGMA analysis. The genetic similarity values ranged from 100% to 76% were observed in three major groups, suggesting close genetic relatedness of them. Exceptionally, PER-007 and PER-017 were involved in outgroup.

• Weed & Turfgrass Science
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• v.1 no.4
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• pp.57-63
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• 2012

This study was carried our to examine the genetic relationship of 13 commercial turfgrass cultivars using Random Amplified Polymorphic DNA to provide genetic informations more efficient golf course management. Analysis of 56 random hexamer primers generated 13 to 54 polymorphic bands among the 13 cultivars with an average of 30.7 bands per primer. The results of cluster analysis based on RAPDs revealed that three major variety groups: Group I - 'Shadow II', 'Aurora Gold', 'Little Bighorn Blue', 'PennA-1', and 'PennA-4'; Group II - 'Midnight II', 'Prosperity', 'Moon light SLT', 'Bright star SLT', and 'Silver dollar'; and Group III - 'Olympic Gold', 'Silver Star', and 'Tar Heel II'. The genetic similarity coefficients among 13 turfgrass cultivars ranged from 0.039 to 1.0 with highest coefficient in Group III. Studies on morphological characters and the effective molecular markers such as sequence characterized amplified regions are further needed to identify relationships and genetic diversities within species and among species.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.28-35
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• 2008

Eleven accessions of Hedera helix, three accessions of Hedera rhombea, one accession of Fatshedera lizei, and one accession of Fatsia japonica were collected and their genetic diversity was measured by using 10 RAPD primers. Approximately ninety seven percentage of polymorphism was detected, because broad germplasm, three genus, was used. Total 97 bands were scored and a dendrogram was constructed by using an UPGMA method. Accessions belonging to Hedera helix tightly clustered in one group: eight accessions showed extremely narrow genetic differences and the other three accessions also showed significant similarity. Despite of their genetic similarity, they showed morphological variations. The morphological variation with a narrow genetic differences indicated that the ivy cultivars have been indeed developed from a mutation breeding program. Genetically most unrelated Fatsia japonica showed a genetic distance of 0.63 on the average between other species. An accession from Fatshedera lizei developed by crossing between two genus, Hedera helix and Fatsia japonica, was allocated together with accessions from Hedera rhombea.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.2
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• pp.94-101
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• 2007

Analysis of population structure of Oncorhynchus keta, the most abundant salmon in the East Sea of Korea, has not been much carried out despite its importance as a fishery resource in the North Pacific. Currently, molecular methods are being applied to stock identification and a method of using single nucleotide polymorphisms (SNPs) is getting more popular. In this study, we analyzed the 720 bp long sequence of the mtDNA COIII-ND3-ND4L region in order to examine genetic similarity-dissimilarity among the Korea chum salmons of each stream and their relationship with the Japan chum salmons. A total of 152 individuals were analyzed, 108 from 3 locations of Korea and 44 from 2 locations of japan, which resulted in as many as 29 different haplotypes. Pairwise $F_{ST}$ and AMOVA tests of the populations show that there is no significant population-level genetic difference among the chum salmons analyzed ($F_{ST}<0.07$). On the other hand, haplotype relationships among the individuals reveal that approximately 25% of the Korea salmons consist genetic lineages independent of Japan salmons and also that a genetic lineage exists in the Puk river and the Namdae river salmons independent of the Wangpi river salmons of Korea.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.85-85
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• 2017

Potato is important carbohydrate source over the world in that revealing high productivity per the unit area, and their cultivation area is estimated to be increased to cope with a scarcity of food according to the population increase. Major cultivated species of potato is Solanum tuberosum (2n = 4x = 48) and regarded as being originated in Andes region of South America. The diverse potato genetic resources has been collected and perserved in Highland Agricultural Research Institute (NICS, RDA), and the genetic materials as DNA stock is conserved in National Agrobiodiversity Center(NAS, RDA). The understanding of genetic constitution of conserved diversity is the basis for the germplam management and further utilization. In this study, we analyzed the genetic diversity of potato germplasm(479 accessions) using 24 microsatellite markers which have been internationally used for fingerprinting of potato accession. The allele number and polymorphic information content (PIC) of total accessions per locus was ranged from 2 to 18 (mean = 8.2) and from 0.214 to 0.771 (mean = 0.595), respectively. Especially, the accession originated from Korea revealed average allele number of 6.0 (2 - 11) and average PIC value of 0.58 (0.193 - 0.763). Three groups were deduced by phylogenic analysis (Group-1, -2, -3); Korean accessions showed close genetic similarity to Japanese and USA accessions, and Korean landraces were mainly included in Group-3. We try to elaborate the genetic diversity analysis of conserved potato germplasm by acquiring more genotypes using applicable molecular markers.

• Journal of Aquaculture
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• v.20 no.4
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• pp.255-259
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• 2007

Genetic diversity among four populations of Chinese shrimp Fenneropenaeus chinensis from Narodo, Yeonggwang, Taean and Chinese Bohai Bay was assessed by amplified fragment length polymorphism (AFLP) DNA fingerprinting. Total numbers of AFLP bands generated (ranging from 251 to 254) and average percent of polymorphic bands (27.1 to 28.1 %) were similar in the four populations. Heterozygosity and genetic diversity within or among the populations were very low for the populations with average values ranging from 0.1177 to 0.1288 and from 0.1099 to 0.1194, respectively. Analyses of pairwise distance, Fst index and genetic similarity among the populations also revealed the similar results with very low genetic differentiation each other. These results suggest that all the wild populations tested in the present analysis may be belonging to the same genetic origin, and also that they may have a close relationship in genetic structure without any significant differentiation.

• Journal of Aquaculture
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• v.21 no.3
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• pp.196-200
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• 2008

Korean spotted barbel Hemibarbus mylodon, is an endangered and endemic freshwater species in the Korean peninsula. Amplified fragment length polymorphism (AFLP) was used to analyze the genetic diversity and population genetic structure of three populations (Bukhan, Namhan and Imjin-river). Fifteen AFLP primer pairs produced 795 products of which 135 were polymorphic(17%). Percentages of polymorphic bands were similar among the three populations, with accounting 11.9%, 11.1%, and 13.4% for Bukhan, Namhan and Imjin-river populations, respectively. An average genetic similarity among the three populations was 0.969. The average heterozygosity (0.033-0.040) and genetic diversity (0.036-0.043) were significantly low. Pairwise distance and fixation index analyses of three populations also suggested quite a low genetic differentiation one another. These results would provide a fundamental baseline data to develop the effective strategy for the management and restoration of this endangered fish species.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1998.06a
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• pp.208-212
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• 1998

This paper suggests the method to recognize the various defect patterns of cold mill strip using binary decision tree constructed by genetic algorithm automatically. In case of classifying the complex the complex patterns with high similarity like the defect patterns of cold mill strip, the selection of the optimal feature set and the structure of recognizer is important for high recognition rate. In this paper genetic algorithm is used to select a subset of the suitable features at each node in binary decision tree. The feature subset of maximum fitness is chosen and the patterns are classified into two classes by linear decision function. After this process is repeated at each node until all the patterns are classified respectively into individual classes. In this way , binary decision tree classifier is constructed automatically. After construction binary decision tree, the final recognizer is accomplished by the learning process of neural network using a set of standard p tterns at each node. In this paper, binary decision tree classifier is applied to recognition of the defect patterns of cold mill strip and the experimental results are given to show the usefulness of the proposed scheme.

• The Plant Pathology Journal
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• v.22 no.1
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• pp.28-35
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• 2006

Virulence and genetic diversity were studied using 21 isolates of Sclerospora graminicola, the pearl millet downy mildew pathogen collected from major pearl millet growing areas of India. Variability for virulence was determined by inoculating a set of 10 differential hosts with the S. graminicola isolates in a greenhouse. The isolates varied for latent period (6.4 to 11 days), disease incidence (0 to $98\%$), virulence index (0 to 18.7) and oospore-production potential (1 to 4). Among the 21 isolates, Sg 139 (Rajasthan) was the most virulent and Sg 110 (Tamil Nadu) the least virulent. Based on virulence index (disease incidence$\time$slatent $period^{-1}$), the 21 isolates were classified into eight virulence groups. Genetic diversity among isolates was studied using AFLP markers. Based on similarity index of banding pattern, the 21 isolates were clustered into eight genotypic groups. The AFLP groupings, however, did not match with that of the virulence groupings, and these two were found independent. The isolate Sg 139 that remained distinct in both pathogenic and genetic groupings indicated its highly virulent nature. Implications of these results in downy mildew resistance breeding are discussed.

• Journal of Life Science
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• v.9 no.1
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• pp.14-16
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• 1999

Genetic variability was monitored by random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) in dicofol-susceptible (S), dicofol-resistant (R) and its reverse-selected (RS) strains of two-spotted spider mite, of Tetranychus urticae. Before the reverse-selection, RS strain, selected reversely from R strain, was 23-fold resistance ratio at {TEX}$LC_{50}${/TEX} to S strain. The resistance was started to in incline slowly to the resistance level of S strain after one year, and the resistance ratio was 4-fold in the 7 years after then. PCR-amplification of T. urticae DNA showed polymorphism in the amplifications with 12 primers in 100 kinds of arbitrary DNA sequences. RAPD amplification with primer OPR-12 (5`-ACAGGTGCGT-3`) showed amplified bands at 1,000 base pair in the S-and RS-strain, and at 350 base pair in R-strain. The results of polymorphism are genetic variabilities derived from development and selection of resistance in each strain. The peculiarly amplified fragments were guessed to participate in dicofol resistance. From the analysis of genetic similarity, it is inferred the gene composition of S-and RS-strain is much closer than that of R-strain.