• Journal of Crop Science and Biotechnology
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• v.10 no.2
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• pp.98-105
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• 2007

Phylogenetic relationships in Korean watermelons were evaluated by genetic similarity coefficients using 15 SSR(simple sequence repeat), 14 SCAR(sequence characterized amplified region) and 14 CAPS(sequence characterized amplified region) markers. The SSR markers were selected from previously reported melon and watermelon SSRs through testing polymorphisms within a set of commercial $F_1$ varieties. The SCAR and CAPS markers were developed from polymorphic AFLP(amplified fragment length polymorphism) markers between inbred lines 'BN4001' and 'BN4002'. From the AFLP analysis, 105 polymorphic fragments were identified between the inbred lines using 1,440 primer combinations of EcoRI+CNNN and XbaI+ANNN. Based on the sequencing data of these polymorphic fragments, we synthesized sequence specific primer pairs and detected clear and reliable polymorphisms in 27 primer pairs by indels(insertion/deletion) or RFLP(restriction fragment length polymorphism). A total of 43 sequence-based PCR markers were obtained and polymorphic information content(PIC) was analyzed to measure the informativeness of each marker in watermelon varieties. The average PIC value of SCAR markers was 0.41, which was similar to that of SSR markers. Genetic diversity was also estimated by using these markers to assess the phylogenetic relationships among commercial varieties of watermelon. These markers differentiated 26 Korean watermelon varieties into two major phylogenetic groups, but this grouping was not significantly correlated with their morphological and physiological characteristics. The mean genetic similarity was 66% within the complete set of 26 commercial varieties. In addition, these sequence-based PCR markers were reliable and useful to identify cultivars and genotypes of watermelon.

• Korean Journal of Plant Taxonomy
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• v.43 no.3
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• pp.236-243
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• 2013

Many plant species in subalpine regions are under threat of extinction as a result of climate change. In this study, the genetic diversity and geographic differentiation of three regions and six populations of Primula farinosa subsp. modesta (Bisset & Moore) Pax in Korea were assessed using the ISSR (Inter Simple Sequence Repeat) marker. The average genetic diversity (P = 60.62, SI = 0.299, h = 0.190) was relatively lower than that of other long-lived perennials, even though it is a self-incompatible species. AMOVA analysis showed that 50% of the total genetic diversity was partitioned among regions and Bayesian cluster analysis showed some remarkable geographic trends that were structured into 2 or 3 regions, suggesting limited gene flow among regions. Considering the population fragmentation, low level genetic diversity, and high genetic differentiation, it is essential to establish in situ and ex situ conservation strategies for P. farinosa subsp. modesta.

• Journal of Life Science
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• v.16 no.6
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• pp.949-954
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• 2006

Soybean [Glycine max (L.) Merr.] is an important crop, accounting for 48% of the world market in oil crops. Improvement of the quality and quantity of soybean seed constituents is one of the most important objectives in soybean breeding. Protein content and seed size are important properties to determine the quality of tofu and soy sprouts respectively. The objective of this study was to identify quantitative trait loci (QTLs) that control seed weight, protein and oil content in soybean. The 117 $F_{2:10}$ recombinant inbred lines (RlL) developed from a cross of 'Keunolkong' and 'Shinpaldalkong' were used. Narrow-sense heritability estimates based on a plot mean on seed weight, protein and oil content were 0.8, 0.78 and 0.71, respectively. Four independent QTLs for seed weight were identified from linkage group (LG) F, I and K. Five QTL for protein content were located on LG D1b, E, H, I and L. Oil content was related with six QTLs located on LG D1b, E, G, I, J and N. Protein and oil content have three common QTLs on LG D1b, E and I. Thus, we identified major loci improving soybean seed quality.

• Horticultural Science & Technology
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• v.35 no.1
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• pp.108-120
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• 2017

Modern watermelon cultivars (Citrullus lanatus [Thunb.] Matsum.& Nakai var. lanatus) have fruits with diverse phenotypes, including fruit shape, rind patterns, and flesh color. Molecular markers enable efficient selection of plants harboring desirable phenotypes. In the present study, publicly available DNA markers tightly linked to fruit shape, rind stripe pattern, and flesh color were evaluated using 85 watermelon accessions with diverse fruit phenotypes. For fruit shape, the dCAPS SUN - Cla011257 marker revealed an 81% of marker - trait match for accessions with elongated or round fruits. For rind stripe pattern, the SCAR wsb6-11marker was effective for selecting Jubilee-type rind pattern from other rind patterns. For flesh color, the Clcyb.600 and Lcyb markers derived from a mutation in the Lycopene ${\beta}$ - cyclase (Lcyb) gene, were effective at selecting red or yellow flesh. Forty-eight accessions possessing diverse fruit - related traits were selected as a reference array and their genetic relationships assessed using 16 SSR markers. At a coefficient of 0.11, the 48 accessions grouped into two major clades: Clade I and Clade II. Clade I subdivided further into subclades I - 1 and I - 2 at a coefficient of 0.39. All accessions with colored flesh were classified into Clade I, whereas those with white - flesh were classified into Clade II. Differences in fruit traits between subclades I - 1 and I - 2 were observed for rind pattern and fruit color; a majority of the accessions with Crimson-type striped or non-striped rind were grouped together in subclade I - 1, while most accessions in subclade I - 2 had a Jubilee - type rind stripe pattern. These results imply that reference array watermelon accessions possess distinguishable genetic structure based on rind stripe pattern. However, no significant grouping pattern was observed based on other fruit-related traits.

• Journal of Korean Society of Forest Science
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• v.87 no.3
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• pp.422-428
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• 1998

Polymerase chain reaction(PCR)-based inter-simple sequence repeats(I-SSR) markers were analyzed in 48 megagametophytes of a single tree of Abies koreana $W_{ILS}$. Nineteen of the 35 primers, screened with 6 megagametophyte DNA and produced the clearest amplification products in the preliminary experiment, were used for PCR with 48 megagametophyte DNAs sampled from a single tree. On the basis of the chi-square test, a total of 51 amplicons, amplified by the 19 primers, were revealed to be segregated according to the Mendelian ratio(i.e., 1 : 1 segregation ratio) in the 48 megagametophytes at 5% significance level. Based on the linkage analysis, the observed 51 Mendelian loci turned out to be unlinked each other, which suggested that they are evenly distributed in the genome. However, majority of RAPD markers are known to belong to the independent linkage blocks, which frequently results in the amplification of RAPD markers from the restricted regions of the genome. Owing to the nature of even distribution of the 51 loci observed in this study, the I-SSR markers could give better resolution of estimating genetic diversity from the whole genome than RAPD markers. And I-SSR markers are also more suitable than RAPD markers for reconstructing phylogenetic relationship by a cladistic method which requires to fulfil the assumption of independent evolution of the different characters.

• Journal of Crop Science and Biotechnology
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• v.11 no.4
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• pp.263-268
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• 2008

Bacterial leaf pustule (BLP) caused by Xanthomonas axonopodis pv. glycines is a serious disease to make pustule and chlorotic haloes in soybean [Glycine max (L). Merr.]. While inheritance mode and map positions of the BLP resistance gene, rxp are known, no sequence information of the gene was reported. In this study, we made five near isogenic lines (NILs) from separate backcrosses (BCs) of BLP-susceptible Hwangkeumkong $\times$ BLP-resistant SS2-2 (HS) and BLP-susceptible Taekwangkong$\times$ SS2-2 (TS) through foreground and background selection based on the four-stage selection strategy. First, 15 BC individuals were selected through foreground selection using the simple sequence repeat (SSR) markers Satt486 and Satt372 flanking the rxp gene. Among them, 11 BC plants showed the BLP-resistant response. The HS and TS lines chosen in foreground selection were again screened by background selection using 118 and 90 SSR markers across all chromosomes, respectively. Eventually, five individuals showing greater than 90% recurrent parent genome content were selected in both HS and TS lines. These NILs will be a unique biological material to characterize the rxp gene.

• 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.

• Journal of Plant Biotechnology
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• v.43 no.4
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• pp.457-465
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• 2016

Microsatellites are one of the most suitable markers for identification of variety, as they have the capability to discriminate between narrow genetic variations. The polymorphism level between 120 microsatellite primer pairs and 148 soybean varieties was investigated through the fluorescence based automatic detection system. A set of 16 primer pairs showed highly reproducible polymorphism in these varieties. A total of 204 alleles were detected using the 16 microsatellite markers. The number of alleles per locus ranged from 6 to 28, with an average of 12.75 alleles per locus. The average polymorphism information content (PIC) was 0.86, ranging from 0.75 to 0.95. The unweighted pair group method using the arithmetic averages (UPGMA) cluster analysis for 148 varieties were divided into five distinctive groups, reflecting the varietal types and pedigree information. All the varieties were perfectly discriminated by marker genotypes. These markers may be useful to complement a morphological assessment of candidate varieties in the DUS (distinctness, uniformity and stability) test, intervening of seed disputes relating to variety authentication, and testing of genetic purity in soybean varieties.

• Journal of Life Science
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• v.14 no.2
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• pp.339-344
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• 2004

Identification of individual quantitative trait loci (QTL) is a prerequisite to application of marker-assisted selection for stern length. Two simple sequence repeat (SSR)-based linkage maps were constructed from recombination inbred line populations between cross of Keunolkong and Shinpaldalkong. Two parents used differed greatly in stem length, which were 30.57 cm and 49.75 cm in Keunolkong and Shinpaldalkong, respectively. Using the constructed maps, regression analysis and interval mapping were performed to identify QTLs conferring stem length. Four QTLs for stem length on linkage groups (LG) F, J, N and O were identified in the Keunolkong ${\times}$ Shinpaldalkong population and they totally explained 37.83% of variation for stem length. In the population, two major QTLs on LG J and O conditioning 14.25% and 10.68% of the phenotypic variation in stem length were determined and two QTLs with minor effect were detected on LG F and N. Identification of QTLs for stem length and mapping individual locus should facilitate to describe genetic mechanisms for stem length in different population. SSR markers tightly linked to QTLs for stem length allow to accelerate the elimination of deleterious genes and selection for desirable recombinants at early stage in crop breeding programs.

• Korean Journal of Medicinal Crop Science
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• v.25 no.6
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• pp.361-366
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• 2017

Background: In the herbal medicinal industry, Angelica gigas Nakai, Angelica sinensis (Oliv.) Diels. and Angelica acutiloba (Siebold & Zucc.) Kitag. are often confused, because the roots of the three species can not be distinguished by their appearance. This confusion can cause serious side effects. In this study, we determined the origins of Angelica roots distributed in the Korean market using the simple sequence repeat (SSR) markers developed based on the A. gigas chloroplast DNA sequence. Methods and Results: We collected twenty seven A. gigas and three A. acutiloba samples from the Seoul, Daegu, and Cheongju herbal medicinal markets. Fifty sections of one collection were mixed and ground to make a powder, which was used for DNA extraction using the cetyl trimethylammonium bromide (CTAB) method. Chloroplast based SSR markers were applied to the DNA for the determination of the species. In addition, polymorphism was found in eight samples. The phylogenetic analysis showed that the A. gigas roots collected from herbal medicinal markets were clearly discriminated from A. sinensis and A. acutiloba even though they were grouped into four clusters. Conclusions: This study showed that chloroplast based SSR markers would help the discrimination of Angelica roots in the Korean herbal medicinal industry and the markers are useful to prevent confusion between Angelica roots.