• 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.

• Plant Breeding and Biotechnology
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• v.7 no.3
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• pp.186-199
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• 2019

We selected 68 Chinese maize inbred lines to understand the genetic diversity, population structure, and marker-trait associations for eight agronomic traits and 50 simple sequence repeats (SSRs) markers. In this study, effective traits, such as days of anthesis (DA), days of silking (DS), ear height (EH), plant to ear height ratio (ER), plant height (PH), and leaf width (LW) were divided into PC1 and PC2 by PCA analysis for maize inbred lines. Genetic diversity analysis revealed a total of 506 alleles at 50 SSR loci. The mean number of alleles per locus was 10.12. The averages of genetic diversity (GD) and polymorphic information content (PIC) values were 0.771 and 0.743, respectively. Based on a membership probability threshold of 0.80, the population structure revealed that the total inbred lines were divided into three major groups with one admixed group. A marker-trait association using Q + K MLM showed that nine SSR markers (bnlg1017, umc2041, umc2400, bnlg105, umc1229, umc1250, umc1066, umc2092, and umc1426) were related with seven agronomic traits. Among these SSR markers, eight SSR markers were associated with only one agronomic trait (DA, DS, ER, LL, LW, PH, and ST), whereas one SSR marker (umc1229) was associated with two agronomic traits (DA and ST). These results will help in optimizing the choice of inbred lines for cross combinations, as well as in selecting markers for further maize breeding programs.

• Genomics & Informatics
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• v.9 no.4
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• pp.189-193
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• 2011

Simple sequence repeats (SSRs) are ubiquitous short tandem duplications found within eukaryotic genomes. Their length variability and abundance throughout the genome has led them to be widely used as molecular markers for crop-breeding programs, facilitating the use of marker-assisted selection as well as estimation of genetic population structure. Here, we report a software application, "SSR-Primer Generator " for SSR discovery, SSR-primer design, and homology-based search of in silico amplicons from a DNA sequence dataset. On submission of multiple FASTA-format DNA sequences, those analyses are batch processed in a Java runtime environment (JRE) platform, in a pipeline, and the resulting data are visualized in HTML tabular format. This application will be a useful tool for reducing the time and costs associated with the development and application of SSR markers.

• Journal of Korean Society of Forest Science
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• v.95 no.4
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• pp.435-442
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• 2006

A total of 167 peculiar haplotypes confirmed from 28 cpSR variants that were observed in 19 populations of Japanese red pine in Korea through cpSSR marker analysis. Thirteen individuals that showed identical haplotype dispersed evenly in 10 populations, and the average number of effective haplotype within population was 13.37. Estimate of genetic diversity (He) was 0.987 on the basis of cpSSR haplotype variants that was equivalent to or higher than the estimates reported in other studies on some forest tree species. Estimation of genetic diversity (S.I.) on the basis of cpSSR variants composing each haplotype revealed the highest estimate of 1.109 for the population of Gangwon-Yeongwol and the lowest estimate of 0.411 for the population of Gyeongbuk Mungyeong with the average of 0.887. Most of observed cpSSR variants appeared to exist commonly in 19 populations (97.62%), and genetic differentiation of cpSSR variants among populations was turned out to be weak (${\Phi}_{ST}=0.024$). Relatively fast rate of mutation of cpSSR marker might be a major cause for such weak population differentiation. There was no identical haplotype shared between 39 population pairs of 173 pair-wise population pairs. Estimation of genetic distance among 19 populations on the basis of population pairs was also impossible, that might be resulted from restricted migration among 19 populations. Considering the observed distribution patterns of cpSSR variants in addition to the previous studies on I-SSR variants, informations on the present geographic location and genetic status of populations should be considered together for effective sustainable management of the genetic resources of Japanese red pine in Korea.

• Korean Journal of Breeding Science
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• v.40 no.3
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• pp.215-222
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• 2008

Fifty-two Korean japonica rice cultivars were analyzed for leaf blast resistance and genotyped with 4 STS and 26 SSR markers flanking the specific chromosome sites linked with blast resistance genes. In our analysis of resistance genes in 52 japonica cultivars using STS markers tightly linked to Pib, Pita, Pi5(t) and Pi9(t), the blast nursery reaction of the cultivars possessing the each four major genes were not identical to that of the differential lines. Eight of the 26 SSR markers were associated with resistant phenotypes against the isolates of blast nursery as well as the specific Korean blast isolates, 90-008 (KI-1113), 03-177 (KJ-105). These markers were linked to Pit, Pish, Pib, Pi5(t), Piz, Pia, Pik, Pi18, Pita and Pi25(t) resistance gene loci. Three of the eight SSR markers, MRG5836, RM224 and RM7102 only showed significantly associated with the phenotypes of blast nursery test for two consecutive years. These three SSR markers also could distinguish between resistant and susceptible japonica cultivars. These results demonstrate the usefulness of marker-assisted selection and genotypic monitoring for blast resistance of rice in blast breeding programs.

• Journal of Crop Science and Biotechnology
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• v.10 no.3
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• pp.159-162
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• 2007

Soybean Kunitz trypsin inhibitor(SKTI) protein is a small, monomeric and non-glycosylated protein containing 181 amino acid residues and is responsible for the inferior nutritional quality of unheated or incompletely heated soybean meal. The objective of this research is to confirm SSR marker(Satt228) tightly linked to the Ti locus using several germplasm accessions with TiTi or titi genotypes for MAS in soybean breeding programs. TiTi genotypes('Jinpumkong2', 'Clark', and 'William') had allele1 and titi genotypes(PI196168, C242, W60, and PI157440) had allele2 in Satt228 marker analysis. 'Jinpumkong2', 'Clark', and 'William'(TiTi genotype) had a Kunitz trypsin inhibitor protein of 21.5 kDa size, and PI196168, C242, W60, and PI157440(titi genotype) did not have the band in protein gel electrophoresis from the mature seed. Cosegregation between the SKTI protein(21.5 kDa size) and allele of Satt228 marker was observed in seven germplasm accessions with different genetic backgrounds. Any recombination between the SKTI protein and allele of the Satt228 marker was not observed. This result indicates that Satt228 marker may effectively utilized to select the plants with the titi genotype.

• Journal of Korean Society of Forest Science
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• v.102 no.2
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• pp.264-271
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• 2013

Mating system parameters were estimated in a natural population of Pinus koraiensis which was located at Gwongeumseong in Mt. Seorak, South Korea. The estimated parameters from allozyme were as follows: 0.882 of multilocus outcrossing rates($t_m$), 0.881 of singlelocus outcrossing rates($t_s$), 0.368 of correlated paternity($r_p$), and 2.7 of number of effective pollen contributors. The estimated parameters from cpSSR markers were as follows: 0.831 of average of outcrossing rates and 12.4 of the average number of effective pollen contributors. The average outcrossing rate from two genetic markers was 0.857, which was similar to those estimated in other conifer species. More number of potential pollen contributors was estimated from cpSSR marker analysis compared with that estimated from allozyme marker analysis. This result sugges$t_s$ that cpSSR markers may be more useful than allozyme markers for identifying potential pollen contributors in the analysis of mating system.

• Journal of Mushroom
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• v.14 no.4
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• pp.174-178
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• 2016

Simple sequence repeats (SSR), also referred to "microsatellites" consist of tandemly repeated short DNA sequence motifs and have been applied in various marker-based studies. SSRs were isolated and characterized from 'Heuktari' and 'Miso', which are major oyster mushroom cultivars in Korea, by genome sequencing and bioinformatic analysis. The genome sizes of 'Heuktari' and 'Miso' were estimated to be 40.8 and 40.3 Mb, respectively, which are larger than those of other P. ostreatus species (PC9 and PC10) and smaller than those of P. eryngii (KNR2312P5). In total, 949 and 968 SSRs were found in the 'Heuktari' and 'Miso' genomes, respectively. Comparative analysis of five mushrooms including P. ostreatus var. florida (PC9 and PC15) and P. eryngii revealed that the number of SSRs in 'Heuktari' and 'Miso' were the highest among them. All mushrooms studied showed similar SSR distribution patterns. Tri-, hexa-, and octanucleotide motifs accounted for the top three fractions of all SSRs.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.434-441
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• 2018

High-density genetic linkage mapping is critical for undertaking marker-assisted selection and confirming quantitative trait loci, as well as helping to build pseudomolecules of genomes. We constructed a genetic map using 94 $F_1$ populations generated from the interspecific cross between Korean cultivar "Wonwhang" (Pyrus pyrifolia, NCBI BioSample SAMN05196235) and European cultivar "Bartlett" (Pyrus communis). We designed a total of 24,267 SSR markers based on the genome sequences of "Wonwhang" for this. To select the markers that are linked to the traits important in pear breeding programs, SSR-containing genomic sequences were subjected to nucleotide sequence homology searches, which resulted in 510 SSR markers with high similarity to genes encoding proteins with putative functions such as transcription factors, resistance proteins, flowering time, and regulatory genes. Of these, 70 markers showed polymorphisms in parents and segregating populations and were used to construct a genetic linkage map, together with the unpublished 579 SNPs obtained from genotyping by sequencing analysis. The genetic linkage map covered 3,784.2 cM and the average distance between adjacent markers was 5.8 cM. Seventy SSR markers were distributed across 17 chromosomes with more than one locus.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.536-542
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• 2000

A linkage map for Japanese red pine (Pinus densiflora) was constructed on the basis of two DNA marker systems of random amplified polymorphic DNAs (RAPDs) and inter-simple sequence repeats (I-SSR). Haploid genomic DNAs were extracted from megagametophyte tissues of 96 individual seeds in a single tree. A total of 98 DNA markers including 52 RAPD markers amplified by 25 primers and 46 I-SSR markers amplified by 18 primers were verified as Mendelian loci showing 1 : 1 segregation in 96 megagametophytes which were ${\chi}^2$-tested at 5% significance level. Of them, 63 segregating loci turned out to be linked into 20 linkage groups by the two-point analysis. However, 35 loci (17 RAPD and 18 I-SSR) of the 98 segregating loci did not coalesced into any linkage groups at a LOD of 3.0. The linked 63 loci were separated by an average distance of about 25.5 cM, which were spanned 1097.8 cM as a whole. The minimum and maximum map distances of the linkage groups were 4.3 cM and 54.9 cM, respectively. Incorporation of I-SSR loi into linkage map of RAPD loci resulted in extended and partially more saturated linkage blocks.