• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.297-302
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• 2003

Genetic linkage maps serve the plant geneticist in a number of ways, from marker assisted selection in plant improvement to map-based cloning in molecular genetic research. Genetic map based upon DNA polymorphism is a powerful tool for the study of qualitative and quantitative traits in crops. The objective of this study was to develop genetic linkage map of soybean using the population derived from the cross of Korean soybean cultivar 'Kwangkyo, and wild accession 'IT182305'. Total 1,000 Operon random primers for RAPD marker, 49 combinations of primer for AFLP marker, and 100 Satt primers for SSR marker were used to screen parental polymorphism. Total 341 markers (242 RAPD, 83 AFLP, and 16 SSR markers) was segregated in 85 $\textrm{F}_2$ population. Forty two markers that shown significantly distorted segregation ratio (1:2:1 for codominant or 3:1 for domimant marker) were not used in mapping procedure. A linkage map was constructed by applying the computer program MAPMAKER/EXP 3.0 to the 299 marker data with LOD 4.0 and maximum distance 50 cM. 176 markers were found to be genetically linked and formed 25 linkage groups. Linkage map spanned 2,292.7 cM across all 25 linkage groups. The average linkage distance between pair of markers among all linkage groups was 13.0 cM. The number of markers per linkage group ranged from 2 to 55. The longest linkage group 3 spanned 967.4 cM with 55 makers. This map requires further saturation with more markers and agronomically important traits will be joined over it.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.2
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• pp.123-127
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• 2000

The objective of this study was to develop a linkage map of soybean under the genetic background of Korean soybean. A set of 89 F/sub 5/ lines was developed from a cross between 'Pureunkong', which was released for soy-bean sprout, and 'Jinpumkong 2', which had no beany taste in seed due to lack of lipoxygenase 1, 2, and 3. A linkage map was constructed for this population with a set of 113 genetic markers including 7 restriction fragment length polymorphism (RFLP) markers, 79 randomly amplified polymorphic DNA (RAPD) markers, 24 simple sequence repeat(SSR) markers, and 3 morphological markers. The map defined approximately 807.4 cM of the soybean genome comprising 25 linkage groups with 98 polymorphic markers. Fifteen markers remained unlinked. Seventeen linkage groups identified here could be assigned to the respective 13 linkage groups in the USDA soybean genetic map. RFLP and SSR markers segregated at only single genetic loci. Fourteen of the 25 linkage groups contained at least one SSR marker locus. Map positions of most of the SSR loci and their linkages with RFLP markers were consistent with previous reports of the USDA soybean linkage groups. For RAPD, banding patterns of 13 decamer primers showed independent segregations at two or more marker loci for each primer. Only the segregation at op Y07 locus was expressed with codominant manner among all RAPD loci. As the soybean genetic map in our study is more updated, molecular approaches of agronomically important genes would be useful to improve Korean soybean improvement.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.4
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• pp.341-343
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• 2001

Molecular markers have become fundamental tools for crop genome study. The objective of this study was to construct a genetic linkage map for cowpea with PCR-based molecular markers. Five hundred and twenty random RAPD primers were screened for parental polymorphism. Ninety RAPD markers from sixty primers was segregated in 75 F2 mapping population derived from the cross of local cultivars GSC01 and GSC02. 70 RAPD markers were found to be genetically linked and formed 11 linkage groups. Linkage map spanned 474.1 cM across all 11 linkage groups. There are six linkage groups of 40 cM or more, and five smaller linkage groups range from 4.9 to 24.8 cM. The average linkage distance between pairs of markers among all linkage groups was 6.87 cM. The number of markers per linkage group ranged from 2 to 32. The longest group 1 spans 190.6 cM, while the length of shortest group 11 is 4.9 cM. This map is further needed to be saturated with the various markers such as RFLP, AFLP, SSR and more various populations and primers. In addition, morphological markers and biochemical markers should be united to construct a comprehensive linkage map.

• Molecules and Cells
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• v.20 no.2
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• pp.201-209
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• 2005

We have constructed an AFLP-based linkage map of Japanese red pine (Pinus densiflora Siebold et Zucc.) using haploid DNA samples of 96 megagametophytes from a single maternal tree, selection clone Kyungbuk 4. Twenty-eight primer pairs generated a total of 5,780 AFLP fragments. Five hundreds and thirteen fragments were verified as genetic markers with two alleles by their Mendelian segregation. At the linkage criteria LOD 4.0 and maximum recombination fraction 0.25(${\theta}$), a total of 152 markers constituted 25 framework maps for 19 major linkage groups. The maps spanned a total length of 2,341 cM with an average framework marker spacing of 18.4 cM. The estimated genome size was 2,662 cM. With an assumption of equal marker density, 82.2% of the estimated genome would be within 10 cM of one of the 230 linked markers, and 68.1% would be within 10 cM of one of the 152 framework markers. We evaluated map completeness in terms of LOD value, marker density, genome length, and map coverage. The resulting map will provide crucial information for future genomic studies of the Japanese red pine, in particular for QTL mapping of economically important breeding target traits.

• BMB Reports
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• v.35 no.5
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• pp.465-471
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• 2002

From fruiting bodies of L. edodes strain L-54, single-spore isolates (SSIs) were collected. Two parental types of L-54 were regenerated via monokaryotization. By means of random-amplified polymorphic DNA (RAPD), DNA samples from L-54, its two parental types, and 32 SSIs were amplified with arbitrary primers. Dedikaryotization was demonstrated, and 91 RAPD-based molecular markers were generated. RAPD markers that were segregated at a 1:1 ratio were used to construct a linkage map of L. edodes. This RAPD-linkage map greatly enhanced the mapping of other inheritable and stable markers [such as those that are linked to a phenotype (the mating type), a known gene (priA) and a sequenced DNA fragment (MAT)] with the aid of mating tests, bulked-segregant analysis, and PCR-single-strand conformational polymorphism. These markers comprised a genetic map of L. edodes with 14 linkage groups and a total length of 622.4 cM.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1129-1134
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• 1999

The rapid development of the sheep genetic linkage map over the last five years has given us the ability to follow the inheritance of chromosomal regions. Initially this powerful resource was used to find markers linked to monogenic traits but there is now increasing interest in using the genetic linkage map to define the complex of genes that control multigenic production traits. Of particular interest are those production traits that are difficult to measure and select for using classical quantitative genetic approaches. These include resistance to disease where a disease challenge (necessary for selection) poses too much risk to valuable stud animals and meat and carcass qualities which can be measured only after the animal has been slaughtered. The goal for the new millennium will be to fully characterise the genetic basis of multigenic production traits. The genetic linkage map is a vital tool required to achieve this.

• Korean Journal of Plant Resources
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• v.10 no.3
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• pp.241-246
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• 1997

Linkage maps based on molecular markers are valuable tools in plant breeding and genetic studies. A population of 76 RI lines from the mating of A3733 and PI437.088 was evaluated with Random Amplified Polymorphic DNA(RAPD) and Simple Sequence Repeats (SSR) markers to create soybean molecular linkage map, 302 RAPD and 21 SSR markers were genetically linked and formed forty linkage groups. These linkage groups spanned a genetic distance of 1,775 cM. The average distance between markers was 5.5 cM.

• Korean Journal of Plant Tissue Culture
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• v.27 no.5
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• pp.367-373
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• 2000

We have constructed a molecular linkage map of chili pepper (Capsicum spp.) in an interspecific (C. annuum cv. TF68 x C. chinense cv. Habanero) F$_2$ population of 107 plants with 150 RFLP and 430 AFLP markers. The resulting linkage map consists of 11 large (206-60.3 cM) and 5 small (32.6- 10.3 cM) linkage groups cover-ing 1,320 cM with an average map distance between framework markers of 7.5 cM. Most (80%) of the RFLP markers were pepper-derived clones and these markers were evenly distributed across the genome. By using 30 primer combinations, 444 AFLP markers were generated in the F$_2$population. The majority of the AFLP markers clustered in each linkage group, although PstI/MseI markers were more evenly distributed than Eco RI/MseI markers within the linkage groups. Genes for biosynthesis of carotenoids and capsaicinoids were mapped on our linkage map. This map will provide the basis of studying secondary metabolites in pepper.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.434-443
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• 2018

Genotyping-by-sequencing (GBS) has been used as a viable single nucleotide polymorphism (SNP) validation method that provides reduced representation sequencing by using restriction endonucleases. Although GBS makes it possible to perform marker discovery and genotyping simultaneously with reasonable costs and a simple molecular biology workflow, the standard TASSEL-GBS pipeline was designed for homozygous groups, and genotyping of heterozygous groups is more complicated. To addresses this problem, we developed a GBS pipeline for heterozygous groups that called KNU-GBS pipeline, specifically for apple (Malus domestica). Using KNU-GBS pipeline, we constructed a genetic linkage map consisting of 1,053 SNP markers distributed over 17 linkage groups encompassing a total of 1350.1 cM. The novel GBS pipeline for heterozygous groups will be useful for marker-assisted breeding programs, and diverse heterozygous genome analyses.

• The Plant Pathology Journal
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• v.18 no.5
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• pp.266-270
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• 2002

Inbred lines of Chinese cabbage KU-101 (resistant line against Plasmodiophora brassicae race race 6) and CS-113 (susceptible line) were crossed and their progeny lines F$_1$, BC$_1$F$_1$, F$_2$, and F$_3$ were produced for the construction of the genetic linkage map of R brassicae race 6-resistant Brassica campestris ssp. pekinensis genome. Restriction fragment length polymorphism (RFLP) was applied to compare between parents and their f$_2$ progenies with a total of 192 probes and 5 restriction enzymes. The constructed RFLP map covered 1,104 cM with a mean distance between genetic marker of 8.0 cM, and produced 10 linkage groups having 121 genetic loci. The loci of P. brassicae race 6 (CR6)-resistant Brassica genome were determined by interval mapping of quan-titative trait loci (QTL), which resulted from bioassay using the same race of the fungi in P3 population. Resistant loci were estimated in numbers 1 (Gl) and 3 (G3) linkage groups. In the regression test, Gl had a value of4.8 logarithm of odd (LOD) score, while C3 had values of 4.2-7.2. Given these results, the location of the CR6-resistant loci within the Brassica genome map can now be addressed.