• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.236-243
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• 2009

This study was conducted to develop a japonica-type rice cultivar with brown planthopper (BPH) resistance using DNA markers. A doubled haploid (DH) population consisting of 120 pure-lines was established by anther culture of $F_1$ hybrids between 'Samgang', a Tongil type BPH resistance cultivar, and 'Nagdong', a japonica cultivar. To determine the map position of genes responsible for BPH resistance in rice, a genetic map was constructed based on 120 DH lines. A total of 162 molecular markers were classified into 12 linkage groups, covering 1,884 Kosami centimorgan (cM) with an average of 11.6 cM. Five QTLs (qBPR3, qBPR6, qBPR7, qBPR8, and qBPR12) associated with BPH resistance were identified and mapped on chromosomes 3, 6, 7, 8, and 12, respectively, using the genetic map constructed in this study. To analyze the relationship between BPH resistance and agronomic traits, a total of eight QTLs related to the agronomic traits were detected on 12 rice chromosomes. In an analysis of relationships, three QTLs (qBPR3, qBPR7, and qBPR8) showed a linkage with tested agronomic traits. A QTL (qBPR3) located on chromosome 3 (RM282-3023) was closely linked to culm length (qCL3). The QTL (qBPR8) for BPH resistance on the short arm of chromosome 8 also overlapped the region detected in culm length (qCL8).

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.325-333
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• 2006

We describe tests for detecting and locating quantitative traits loci (QTL) for traits in Hanwoo. Lod scores and a permutation test have been described. From results of a permutation test to detect QTL, we select major DNA markers of BMS1167 microsatellite locus in Hanwoo chromosome 17 for further analysis. K-means clustering analysis applied to four traits and eight DNA markers in BMS1167 resulted in three cluster groups. We conclude that the major DNA markers of BMS1167 microsatellite locus in Hanwoo chromosome 17 are markers 100bp, 108bp and 110bp.

• Journal of the Korean Data and Information Science Society
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• v.16 no.4
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• pp.913-921
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• 2005

We describe tests for detecting and locating quantitative traits loci (QTL) for traits in Hanwoo. Lod scores and a permutation test have been described. From results of a permutation test to detect QTL, we select major DNA markers of BMS941 microsatellite locus in Hanwoo chromosome 17 for further analysis. K-means clustering analysis applied to four traits and eight DNA markers in BMS941 resulted in three cluster groups. We conclude that the major DNA markers of BMS941 microsatellite locus in Hanwoo chromosome 17 are markers 80bp, 85bp 90bp and 105bp.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.9
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• pp.1210-1213
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• 2004

Quantitative trait loci (QTL) mapping can be applied to detect chromosomal locations that control economic traits in farm animals. Teat number has been considered as one of the most important factors to evaluate mothering ability of sow. Especially, teat number is more important when the number is less than the litter size. This study was conducted to identify QTL affecting teat number in the Korean native pig${\times}$Landrace resource family. A total of 240 animals was genotyped for 132 polymorphic microsatellites covering the 18 pig autosomes. Mean and standard deviation of teat number in $F_2$animals is 13.46${\pm}$1.40. QTL was analyzed using F2 QTL Analysis Servlet of QTL express. A QTL for teat number on SSC9 was significant at the 1% chromosome-wide level and three suggestive QTL were detected on SSC3, 7 and 14. All QTL detected in this study had additive effect and Landrace alleles were associated with higher teat number in comparison with Korean native pig for three of four QTL.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.102-102
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• 2017

In this study, QTL analysis of allelopathy was conducted. A total of 171 of F8 RILs developed from the cross between Nongan(low allelopathic cultivar) and Sathi(high allelopathic cultivar) were used . the performance of allelopathy were evaluated using 'ECAM(Equal Compartment Agar Method)', where the root length of lettuce cultivated with the RILs were measured. The distribution of the performance was followed as normal distribution. In order to identify the location of QTLs related to allelopathy, QTL-seq with BSA(Bulked-segregant analysis) was performed with 20 highest and 10 lowest RILs. As a result, Two Sliding window coordinate region of candidate QTLs were detected on Chr4 (5,050,001 - 14,800,000, 18,650,001 - 22,500,000), Chr8 (2,550,001 - 8,250,000, 21,150,001 - 26,800,000) and One region on Chr7 (1 - 3,300,000), Chr9 (1 - 13,300,000) respectively.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.291-299
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• 2004

Characterization of quantitative trait loci (QTL) was investigated in the experimental cross population between Berkshire and Yorkshire breed. A total of 512 F$_2$ offspring from 65 matting of F$_1$ parents were phenotyped the carcass traits included average daily gain (ADG), average backfat thickness (ABF), tenth rip backfat thickness (TRF), loin eye area (LEA), and last rip backfat thickness (LRF). All animals were genotyped for 125 markers across the genome. Marker linkage maps were derived and used in QTL analysis based on line cross least squares regression interval mapping. A decision tree to identify QTL with imprinting effects was developed based on tests against the Mendelian mode of QTL expression. To set the evidence of QTL presence, empirical significance thresholds were derived at chromosome-wise and genome-wise levels using specialized permutation strategies. Significance thresholds derived by the permutation test were validated in the data set based on simulation of a pedigree and data structure similar to the Berkshire-Yorkshire population. Genome scan revealed significant evidences for 13 imprinted QTLs affecting growth and body compositions of which nine were identified to be QTL with paternally expressed inheritance mode. Four of QTLs in the loin eye area (LEA), and tenth rip backfat thickness (TRF), a maternally expressed QTL were found on chromosome 10 and 12. These results support the useful statistical models to analyse the imprinting far the QTLs related carcass trait.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.525-536
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• 2004

The objective of this study was to identify the quantitative traits loci(QTL) for meat quality traits in pigs. Three-generation resource population was constructed from a cross between Korean native boars and Landrace sows. The resource population including founders, $F_1$ and $F_2$ was genotyped for 23 microsatellite markers on chromosome 7. The sex average total length of linkage map on chromosome 7 was estimated 154.6 cM. Meat quality traits including meat pH, meat color, drip loss, shear force, heating loss, crude fat, crude protein, crude ash and water content in muscle were collected from $F_2$ animals. For the QTL mapping, we used $F_2$ QTL Analysis Servlet of QTL express for web-based QTL mapping tools(http://qtl.cap.ed.ac.uk/). The QTLs for CIE-a and CIE-b on SSC7 were significantly detected at 1% and 5% chromosome-wide level, respectively.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2003.11a
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• pp.135-137
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• 2003

The analyses of relationship between specific genes and economic traits were performed on the basis of the genetic characterization of Korean native chicken in this study. Three generation reference pedigree was established from the several lines of Korean native chicken and cornish breed for the linkage analysis and many economic traits were collected for QTL(quantitative trait loci) detection. The experimental design were planed to detect QTLs of meat quality and laying performance from those two distinctive breeds.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.477-482
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• 2012

Low-temperature germination is one of the major determinants for stable stand establishment in the rice direct seeding method in temperate regions and at high altitude areas. Quantitative trait loci (QTL) controlling low-temperature germinability in rice were identified using 96 introgression lines (ILs) derived from a cross between Oryza rufipogon and the Korean japonica cultivar, 'Hwaseongbyeo'. The germination rate at $15^{\circ}C$ was measured to represent low-temperature germination and used for QTL analysis. The germination rate at $15^{\circ}C$ for 7 days of Oryza rufipogon and Hwaseongbyeo was 93.3 and 28.7%, respectively, and that of progenies ranged from 0 to 48%. A linkage map was constructed using 135 simple sequence repeat (SSR) markers. Five putative QTLs associated with low-temperature germination were detected on chromosomes 1, 3, 4, 10 and 11. The QTL, qltg10 on chromosome 10 accounted for 19.2% of the total phenotypic variation for low-temperature germinability. Four additional QTL, accounted for 10.4 - 15.1% of the total phenotypic variation. The O. rufipogon alleles in all detected QTLs loci increased the low-temperature germination rate. No QTL associated with low temperature germinability has been detected near the qltg10 QTL in this study suggesting that qltg10 is a new QTL. The locus, qltg10 is of particular interest because of its independence from undesirable height and maturity effects. The DNA markers linked to the QTL for low temperature germinability would be useful in selecting lines with enhanced low temperature germinability in rice breeding program.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.10
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• pp.1359-1365
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• 2009

We performed a genome-wide linkage and quantitative trait locus (QTL) analysis to confirm the existence of QTL affecting Rous Sarcoma Virus (RSV) induced tumor regression, and to estimate their effects on phenotypic variance in an F2 resource population. The F2 population comprised 158 chickens obtained by crossing tumor regressive White Leghorn (WL) and tumor progressive Rhode Island Red (RIR) lines was measured for tumor formation after RSV inoculation. Forty-three tumor progressive and 28 tumor regressive chickens were then used for genome-wide linkage and QTL analysis using a total of 186 microsatellite markers. Microsatellite markers were mapped on 20 autosomal chromosomes. A significant QTL was detected with marker LEI0258 located within the MHC B region on chromosome 16. This QTL had the highest F ratio (9.8) and accounted for 20.1% of the phenotypic variation. Suggestive QTL were also detected on chromosomes 4, 7 and 10. The QTL on chromosome 4 were detected at the 1% chromosome-wide level explaining 17.5% of the phenotypic variation, and the QTLs on chromosome 7 and 10 were detected at the 5% chromosome-wide level and explained 11.1% and 10.5% of the phenotypic variation, respectively. These results indicate that the QTLs in the non-MHC regions play a significant role in RSV-induced tumor regression. The present study constitutes one of the first preliminary reports in domestic chickens for QTLs affecting RSV-induced tumor regression outside the MHC region.