• Animal Bioscience
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• 제35권6호
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• pp.826-837
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• 2022

Objective: Cambodia is located within the distribution range of the red junglefowl, the common ancestor of domestic chickens. Although a variety of indigenous chickens have been reared in Cambodia since ancient times, their genetic characteristics have yet to be sufficiently defined. Here, we conducted a large-scale population genetic study to investigate the genetic diversity and population genetic structure of Cambodian indigenous chickens and their phylogenetic relationships with other chicken breeds and native chickens worldwide. Methods: A Bayesian phylogenetic tree was constructed based on 625 mitochondrial DNA D-loop sequences, and Bayesian clustering analysis was performed for 666 individuals with 23 microsatellite markers, using samples collected from 28 indigenous chicken populations in 24 provinces and three commercial chicken breeds. Results: A total of 92 haplotypes of mitochondrial D-loop sequences belonging to haplogroups A to F and J were detected in Cambodian chickens; in the indigenous chickens, haplogroup D (44.4%) was the most common, and haplogroups A (21.0%) and B (13.2%) were also dominant. However, haplogroup J, which is rare in domestic chickens but abundant in Thai red junglefowl, was found at a high frequency (14.5%), whereas the frequency of haplogroup E was considerably lower (4.6%). Population genetic structure analysis based on microsatellite markers revealed the presence of three major genetic clusters in Cambodian indigenous chickens. Their genetic diversity was relatively high, which was similar to findings reported for indigenous chickens from other Southeast Asian countries. Conclusion: Cambodian indigenous chickens are characterized by mitochondrial D-loop haplotypes that are common to indigenous chickens throughout Southeast Asia, and may retain many of the haplotypes that originated from wild ancestral populations. These chickens exhibit high population genetic diversity, and the geographical distribution of three major clusters may be attributed to inter-regional trade and poultry transportation routes within Cambodia or international movement between Cambodia and other countries.

• Asian-Australasian Journal of Animal Sciences
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• 제27권7호
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• pp.926-931
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• 2014

Pork from Jeju black pig (population J) and Berkshire (population B) has a unique market share in Korea because of their high meat quality. Due to the high demand of this pork, traceability of the pork to its origin is becoming an important part of the consumer demand. To examine the feasibility of such a system, we aim to provide basic genetic information of the two black pig populations and assess the possibility of genetically distinguishing between the two breeds. Muscle samples were collected from slaughter houses in Jeju Island and Namwon, Chonbuk province, Korea, for populations J and B, respectively. In total 800 Jeju black pigs and 351 Berkshires were genotyped at thirteen microsatellite (MS) markers. Analyses on the genetic diversity of the two populations were carried out in the programs MS toolkit and FSTAT. The population structure of the two breeds was determined by a Bayesian clustering method implemented in structure and by a phylogenetic analysis in Phylip. Population J exhibited higher mean number of alleles, expected heterozygosity and observed heterozygosity value, and polymorphism information content, compared to population B. The $F_{IS}$ values of population J and population B were 0.03 and -0.005, respectively, indicating that little or no inbreeding has occurred. In addition, genetic structure analysis revealed the possibility of gene flow from population B to population J. The expected probability of identify value of the 13 MS markers was $9.87{\times}10^{-14}$ in population J, $3.17{\times}10^{-9}$ in population B, and $1.03{\times}10^{-12}$ in the two populations. The results of this study are useful in distinguishing between the two black pig breeds and can be used as a foundation for further development of DNA markers.

• Journal of Korean Society of Forest Science
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• 제102권2호
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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.

• Horticultural Science & Technology
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• 제34권1호
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• pp.142-153
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• 2016

The present study investigated identification of cultivars through phylogenetic analysis of 108 Citrus varieties and related cultivars using simple sequence repeat (SSR) markers. Two hundred three SSR primer pairs were used to detect polymorphic markers among 8 Citrus cultivars consisting of 4 mandarins, 1 orange, 1 tangor, 1 tangelo, and 1 pumelo. Eighteen SSR primer pairs were reproducible and showed highly polymorphic alleles. These markers were applied to assess genetic variations of the 108 varieties. Each marker detected 5-14 alleles, with an average of 9.28. The polymorphism information content varied from 0.417 to 0.791 with an average of 0.706. Cluster analysis with SSR markers resulted in 13 major groups reflecting cultivar types and pedigree information. Twelve orange cultivars in the $I-1^{st}$ sub-cluster and 23 mandarin cultivars in the $II-1^{st}$ sub-cluster, respectively, were not discriminated using the SSR markers. This could be due to narrow genetic backgrounds originated through bud mutation or nucellars seedlings. The SSR profile database of Citrus cultivars will be useful as a tool for protection of plant breeders' intellectual property rights in addition to assessing genetic diversity in Citrus cultivars and germplasms.

• Journal of Mushroom
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• 제15권2호
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• pp.78-83
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• 2017

Microsatellite SSR markers were developed and utilized to reveal the genetic diversity of 32 strains of Flammulina velutipes collected in Korea, China, and Japan. From the SSR-enriched library, 490 white colonies were randomly selected and sequenced. Among the 490 sequenced clones, 85 (17.35%) were redundant. Among the remaining 405 unique clones, 201 (49.6%) contained microsatellite sequences. We used 12 primer pairs that produced reproducible polymorphic bands for four diverse strains, and these selected markers were further characterized in 32 Flammulina velutipes strains. A total of 34 alleles were detected using the 12 markers, with an average of 3.42 alleles, and the number of alleles ranged from two to seven per locus. The major allele frequency ranged from 0.42 (GB-FV-127) to 0.98 (GB-FV-166), and values for observed ($H_O$) and expected ($H_E$) heterozygosity ranged from 0.00 to 0.94 (mean = 0.18) and from 0.03 to 0.67 (mean = 0.32), respectively. SSR loci amplified with GB-FV-127 markers gave the highest polymorphism information content (PIC) of 0.61 and mean allele number of five, whereas for loci amplified with GB-FV-166 markers these values were the lowest, namely 0.03 and two. The mean PIC value (0.29) observed in the present study with average number of alleles (3.42). The genetic relationships among the 32 Flammulina velutipes strains on the basis of SSR data were investigated by UPGMA cluster analysis. In conclusion, we succeeded in developing 12 polymorphic SSRs markers from an SSR-enriched library of Flammulina velutipes. These SSRs are presently being used for phylogenetic analysis and evaluation of genetic variations. In future, these SSR markers will be used in clarifying taxonomic relationships among the Flammulina velutipes.

• Horticultural Science & Technology
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• 제28권4호
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• pp.664-671
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• 2010

A genetic linkage map was constructed using 188 $F_9$ RILs derived from a cross between $Solanum$ $lycopersicum$ H7996 (resistant to bacterial wilt) and $S.$ $pimpinellifolium$ WVa700 (highly susceptible to bacterial wilt). The map consisted of 361 markers including 260 DArTs, 74 AFLPs, 4 RFLPs, 1 SNP, and 22 SSRs. The resulting linkage map was comprised of 13 linkage groups covering 2042.7 cM. The genetic linkage map had an average map distance between markers of 5.7 cM, with an average DArT marker density of 1/7.9 cM. Based on the distribution of anchor SSR markers, 11 linkage groups were assigned to 10 chromosomes of tomato except chromosomes 5 and 12. The DArT markers were distributed across the genome in a similar way as other markers and showed the highest frequency of clustering (38.8%) at ${\leq}$ 0.5 cM intervals between adjacent markers, which is 3 times higher than AFLPs (13.5%). The present study is the first utilization of DArT markers in tomato linkage map construction.

• Plant Breeding and Biotechnology
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• 제6권4호
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• pp.391-403
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• 2018

Genome resequencing by next-generation sequencing technology can reveal numerous single nucleotide polymorphisms (SNPs) within a closely-related cultivar group, which would enable the development of sufficient SNP markers for mapping and the identification of useful genes present in the cultivar group. We analyzed genome sequence data from 13 Korean japonica rice varieties and discovered 740,566 SNPs. The SNPs were distributed at 100-kbp intervals throughout the rice genome, although the SNP density was uneven among the chromosomes. Of the 740,566 SNPs, 1,014 SNP sites were selected on the basis of polymorphism information content (PIC) value higher than 0.4 per 200-kbp interval, and 506 of these SNPs were converted to Kompetitive Allele-Specific PCR (KASP) markers. The 506 KASP markers were tested for genotyping with the 13 sequenced Korean japonica rice varieties, and polymorphisms were detected in 400 KASP markers (79.1%) which would be suitable for genetic analysis and molecular breeding. Additionally, a genetic map comprising 205 KASP markers was successfully constructed with 188 $F_2$ progenies derived from a cross between the varieties, Junam and Nampyeong. In a phylogenetic analysis with 81 KASP markers, 13 Korean japonica varieties showed close genetic relationships and were divided into three groups. More KASP markers are being developed and these markers will be utilized in gene mapping, quantitative trait locus (QTL) analysis, marker-assisted selection and other strategies relevant to crop improvement.

• Journal of Life Science
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• 제25권9호
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• pp.1059-1071
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• 2015

Watermelon and melon are economically important Cucurbitaceae crops. Recently, the development of molecular markers based on the construction of genetic linkage maps and detection of DNA sequence variants through next generation sequencing are essential as molecular breeding strategies for crop improvement that uses marker-assisted selection and backcrossing. In this paper, we intended to provide useful information for molecular breeding of watermelon and melon by analyzing the current status of international and domestic research efforts on genomics and molecular markers. Due to diverse genetic maps constructed and the reference genome sequencing completed in the past, DNA markers that are useful for selecting important traits including yield, fruit quality, and disease resistances have been reported and publicly available. To date, more than 16 genetic maps and loci and linked markers for more than 40 traits have reported for each watermelon and melon. Furthermore, the functional genes that are responsible for those traits are being continuously discovered by high-density genetic map and map-based cloning. In addition, whole genome resequencing of various germplasm is under progress based on the reference genome. Not only by the efforts for developing novel molecular markers, but application of public marker information currently available will greatly facilitate breeding process through genomics-assisted breeding.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.947-953
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• 2008

We studied genetic diversity and relationships among Mongolian goat populations on the basis of microsatellite DNA polymorphisms. DNA samples from eight populations (Bayandelger, Ulgii Red, Zavkhan Buural, Sumber, Zalaajinst White, Erchim Black, Dorgon, and Gobi Gurvan Saikhan) from geographically distinct areas of Mongolia were analyzed by using 10 microsatellite DNA markers. Since the 10 markers were highly polymorphic, the genetic characteristics of these native goat populations could be estimated. Genetic diversity within populations, as estimated by the expected heterozygosities, was high, ranging from 0.719 to 0.746, but genetic differentiation between populations was low, representing only 1.7% of the total genetic variation. The results suggest that Mongolian native goat populations still have a semi-wild genetic structure reflecting traditional Mongolian nomadism and the short history of artificial selection. The genetic relationships among the populations were not clear in the neighbor-joining tree generated from the modified Cavalli-Sforza chord genetic distances. By using principal components analysis, the five core populations of Mongolian native goats (Bayandelger, Ulgii Red, Zavkhan Buural, Sumber, and Dorgon) and the populations crossed with Russian breeds (Zalaajinst White, Erchim Black, and Gobi Gurvan Saikhan) were distinguished. There was no correlation between genetic relationships among the populations and the geographical distribution of the populations.

• Korean Journal of Poultry Science
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• 제23권3호
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• pp.135-144
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• 1996

This study was carried out to clarify the genetic constitution of biochemical polymorphic loci controlling blood protein and enzymes as genetic rnarkers in Korean native chicken(KNG) population Blood samples were collected from 230 KNG representing three colored-lines(reddish-, yellowish- and blackish- brown) raised in Daejeon branch of National Livestock Research Institute. Eight blood marker loci, transferrin(Tf), post-albumin(Pas), albumin(Alb), amylase-1(Arny-1), es-terase-1(Es-1), alkaline phosphatase(Akp), catalase(Cat) and hemoglobin(Hh) were analyzed by using starch, agarose and polyacrylamide gel electrophoresis. Based on the gene frequencies of polymorphic marker loci, the genetic characteristics of KNF population was analyzed, and the genetic ariability within population was quantified. The genetic relationships between KNC and other native fowls or improved breeds were also estimated. The gene frequencies of Tf, Pas and AIb loci were similar to those of improved breeds among the seven biochemical polymorphic loci, while gene frequencies of Cat and Es-i loci were remarkably different between KNC and improved breeds. Gene frequencies of amy-i and Akp loci were similar to those of New Hampshire and Rhode Island Red and White Leghorn, respectively. However in comparison with other improved breeds, great differences were observed in gene frequencies of these loci The average heterozygosity, effective number of alleles and homogeneity index for the seven loci combined were estimated to be .334, 1.639 and .373, respectively. Based on the dendrogram and genetic distances, the KNC was genetically closer to New Hampshire, Plymouth Rock and Rhode Island Red breeds than to the White Leghorn breed.