• Journal of The Korean Association For Science Education
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• v.33 no.3
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• pp.679-693
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• 2013

The purpose of this study is to develop an inventory to classify task commitment types of science learning and to classify highschool students' task commitment types. Firstly, inventory questions were designed following the literature analysis on the task commitment components which involve self confidence, high goal setting, and focused attention. Prototype inventory underwent the content validity test, pilot test, and reliability test. Through these steps, final inventory was input to 462 high school students and underwent the factor analysis and cluster analysis. Factor analysis confirmed three components of task commitment as the three factors of inventory questions. In order to find how many clusters exist, factors of developed inventory became new variables. Each factor's factor mean was calculated and served as the new variable of the cluster analysis. Cluster analysis extracted five clusters as task commitment types. The 5 clusters were suggested by the agglomarative schedule and dendrogram gained from a hierarchical cluster analysis with the setting of the Ward algorithm and Squared Euclidean distance. Based on the factor mean score, traits of each cluster could be drawn out. Inventory developed by this study is expected to be used to identify student commitment types and assess the effectiveness of task commitment enhancement programs.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.375-380
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• 1985

Single linkage dendrograms by Mahalanobis's D$^2$, Q correlation, and distance from Principal Component Analysis, respectively, were made to eight rice breeding lines in the none and high fertilizer levels. The dendrograms in the two fertilizer levels were similar in shape. The shape of dendrograms by D$^2$ and Q correlation were identical and they were very similar in shape to that by PCA in the both fertilizer levels.

• Development and Reproduction
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• v.16 no.4
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• pp.315-320
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• 2012

The gDNA isolated from Cyclina sinensis from Gochang (GOCHANG), Incheon (INCHEON) and a Chinese site (CHINESE), were amplified by PCR. Here, the seven oligonucleotide decamer primers (BION-66, BION-68, BION-72, BION-73, BION-74, BION-76, and BION-80) were used to generate the unique shared loci to each population and shared loci by the three cyclina clam populations. As regards multiple comparisons of average bandsharing value results, cyclina clam population from Chinese (0.763) exhibited higher bandsharing values than did clam from Incheon (0.681). In this study, the dendrogram obtained by the seven decamer primers indicates three genetic clusters: cluster 1 (GOCHANG 01~GOCHANG 07), cluster 2 (INCHEON 08~INCHEON 14), cluster 3 (CHINESE 15~CHINESE 21). The shortest genetic distance that displayed significant molecular differences was between individuals 15 and 17 from the Chinese cyclina clam (0.049), while the longest genetic distance among the twenty-one cyclina clams that displayed significant molecular differences was between individuals GOCHANG no. 03 and INCHEON no. 12 (0.575). Individuals of Incheon cyclina clam population was somewhat closely related to that of Chinese cyclina clam population. In conclusion, our PCR analysis revealed a significant genetic distance among the three cyclina clam populations.

• Journal of Plant Biotechnology
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• v.7 no.2
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• pp.105-112
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• 2005

Buffer soluble protein and five isozymes were analyzed to assess the inter specific relationship among 25 species of the genus Mammillaria Haw. A total of 102 types of proteins were resolved, out of which eighty-six types were found to be polymorphic and only two were unique. A total of 248 bands (isoforms) were detected for 5 isozymes, among them only 4 were found to be monomorphic and 35 were exclusive. Mantel 'Z' statistics revealed wide variations in the correlation among different enzymes. The correlation value 'r' was the highest in case of esterase with pooled data of all the five enzymes. The dendrogram constructed on the basis of pooled data (protein and allozyme) divided the species into two major clusters containing 14 and 11 members respectively. The species M. matudae and M. bella were found to be the most closely related while M. decipience and M. camptroticha were distantly apart. The present study gave an indication of usefulness of the isozyme and protein markers for genetic discrimination between different species of Mammillaria.

• Plant Biotechnology Reports
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• v.4 no.3
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• pp.237-242
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• 2010

Six parent and their 12 gamma ray-induced somatic flower colour mutants of garden rose were characterized to discriminate the mutants from their respective parents and understanding the genetic diversity using Random amplification of polymorphic DNA (RAPD) markers. Out of 20 primers screened, 14 primers yielded completely identical fragments patterns. The other 7 primers gave highly polymorphic banding patterns among the radiomutants. All the cultivars were identified by using only 7 primers. Moreover, individual mutants were also distinguished by unique RAPD marker bands. Based on the presence or absence of the 48 polymorphic bands, the genetic variations within and among the 18 cultivars were measured. Genetic distance between all 18 cultivars varied from 0.40 to 0.91, as revealed by Jaccard's coefficient matrix. A dendrogram was constructed based on the similarity matrix using the Neighbor Joining Tree method showed three main clusters. The present RAPD analysis can be used not only for estimating genetic diversity present in gamma ray-induced mutants but also for correct identification of mutant/new varieties for their legal protection under plant variety rights.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.10a
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• pp.68-68
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• 2018

A total of 47 core collections of pepper (Capsicum chinense Jacq.) conserved in National Agrobiodiversity Center (NAC) were studied under field condition at Jeonju. All accessions were characterized for their 14 qualitative and 16 quantitative characters. Results revealed that both qualitative and quantitative characters exhibited wide variation among the studied germplasm. Distribution of fruit characters (fruit length, width, and fruit wall thickness) among the accessions was positively skewed. Of the 47 accessions evaluated, 38.3% accessions had conical shaped fruits and mature fruit color was predominantly red (51.1%), orange (21.3%) and yellow (14.9%). Principal component analyses revealed that (i) 56.64% of the qualitative (fruit shape, color and fruit surface) variation and (ii) 89.42% of the quantitative (plant width, height and fruit maturity days) variation were explained by the first two components. Clustering revealed two groups and dendrogram revealed morphological variation among accessions. The phenotypic diversity exists in this core collections provide valuable information to improve agronomic traits in pepper breeding program.

• Korean Journal Plant Pathology
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• v.13 no.1
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• pp.5-12
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• 1997

Genetic diversity of forty-four strains of Xanthomonas campestris pv. vesicatoria from diverse geographic origins was investigated using random amplified polymorphic DNA (RAPD) of genomic DNA. One hundred and thirty-seven amplified fragments were produced by polymerase chain reaction with a set of 14 random primers, and the sizes of amplified DNA fragments ranged approximately from 0.3 to 3.2 kb. Cluster analysis of genetic similarity among the strains generated the dendrogram that clearly separated all strains from each other. The 44 strains of X. campestris pv. vesicatoria were classified into 4 major genomic DNA RAPD groups and 15 subgroups at the genetic similarity of 0.60 and 0.92, respectively. The strains from foreign countries formed discrete subgroups, but the United States strain 87-77 clustered closely with some of Korean strains together. Thirty-nine Korean strains were classified into 11 subgroups, and especially Masan strain Ms93-1 clustered distinctly far from the other Korean strains. RAPD polymorphism suggests strongly the occurrence of genetic differentiation of X. campestris pv. vesicatoria and the existence of genetically distinctive subgroups among the populations in Korea.

• Research in Plant Disease
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• v.22 no.4
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• pp.236-242
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• 2016

Bacterial wilt caused by Ralstonia solanacearum is one of the most devastating diseases in major Solanaceae crops. The pathogen is easily disseminated and survives for many years in plant farming system. Although chemicals are applied to control the disease, they are of limited efficacy and cause several problems. Therefore, the use of phage therapy has been suggested to control the disease as a biological agent. In this study, we discovered bacteriophages lysing diverse Ralstonia isolates from plant and soil samples obtained from the potato cultivated field in Jeju. Three times repeated pickings of plaques resulted in obtaining 173 single phages showing diverse spectrum of host-specificity. With the results, 12 core phages were selected and dendrogram was generated. Genetic diversity of the selected phages was also confirmed by AFLP (Amplified Fragment of Length Polymorphism) fingerprinting. The stability of the phages was investigated in various temperatures and various conditions of pH in vitro. The phages were stable at $16^{\circ}C-44^{\circ}C$ and pH 6-10. Morphological characterization of the phages revealed they were all classified into the Podoviridae, but had diverse head sizes. The results of this research will contribute to control the disease and further researches regarding genetic and molecular aspects will facilitate understanding phage and bacteria interaction.

• The Korean Journal of Malacology
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• v.15 no.1
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• pp.63-69
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• 1999

Electrophoretic analysis was carried out to elucidate genetic relationships of four Korean scallops, Patinopecten yessoensis, chlamys ferreri ferreri, Chlamys swifti and Amusium japonicum japonicum, and of a Chinese population of C. ferreri ferreri purchased form a market. Glucose phosphate isomerase banding pattern was highly varied among eight loci. Three populations of C. ferreri ferreri were more closely clustered in a dendrogram within the range of Nei＇s genetic similarity values of 0.730-0.830. P. yessoenensis and Chlamys swifti were clustered with genetic similarity value of 0.647. These two clusters were lineated at the value of 0.598. A. japonicum japonicum was clustered with other three species at value of 0.541.

• Korean Journal of Agricultural Science
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• v.23 no.1
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• pp.99-107
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• 1996

Eighteen nuclear probes were used to examine RFLP(restriction fragment length polymorphism) between six species of Artemisia spp. of Korea. Total DNA from six different species of Artemisia was separately cut with three restrict enzymes. The PstI enzyme was showed to reduce the variation of polymorphisms than the other two enzymes(EcoRl and BamHI). The genetic variation of polymorphism was similar between the Dhewegiki-ssug and Cham-ssug. RAPD analysis was applied to the same six species of Artemisia spp. in order to assess the degree of DNA polymorphism within the Artemisia genus. Six species of Artemisia were evaluated for variation using a set of 11 random 10-mer primers. Nine out of the eleven primers revealed scorable polymorphisms between six species of Artemisia spp. Genetic distances between each of the species were calculated and cluster analysis was used to generate a dendrogram showing phylogenetic relationships between them This result indicates that molecular markers will be more usable in intraspecific study of Artemisia spp. than isoenzyme markers.