• Molecules and Cells
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• v.25 no.3
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• pp.407-416
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• 2008

Thirteen near-isogenic lines (NILs) of japonica rice were developed via a backcross method using the recurrent parent Chucheong, which is of good eating quality but is susceptible to Magnaporthe grisea, and three blast resistant japonica donors, Seolak, Daeseong and Bongkwang. The agro-morphological traits of these NILs, such as heading date, culm length, and panicle length, were similar to those of Chucheong. In a genome-wide scan using 158 SSR markers, chromosome segments of Chucheong were identified in most polymorphic regions of the 13 NIL plants, and only a few chromosome segments were found to have been substituted by donor alleles. The genetic similarities of the 13 NILs to the recurrent parent Chucheong averaged 0.961, with a range of 0.932-0.984. Analysis of 13 major blast resistance (R) genes in these lines using specific DNA markers showed that each NIL appeared to contain some combination of the four R genes, Pib, Pii, Pik-m and Pita-2, with the first three genes being present in each line. Screening of nine M. grisea isolates revealed that one NIL M7 was resistant to all nine isolates; the remaining NILs were each resistant to between three and seven isolates, except for NIL M106, which was resistant to only two isolates. In a blast nursery experiment, all the NILs proved to be more resistant than Chucheong. These newly developed NILs have potential as commercial rice varieties because of their increased resistance to M. grisea combined with the desirable agronomic traits of Chucheong. They also provide material for studying the genetic basis of blast resistance.

• Korean Journal of Plant Taxonomy
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• v.34 no.4
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• pp.335-358
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• 2004

To investigate molecular phylogenetic relationships and to test hypothesis of hybrid origin of Ranunculus cantoniensis (Ranunculaceae), the sequences of nrDNA and chloroplast DNA were analyzed for 8 taxa and 25 accessions including 5 accessions of outgroup. In the phylogenetic trees by analyses of maximum parsimony and maximum likelihood for ITS nrDNA sequences and combined data of psbA-trnH, rps16 and trnL sequences of cpDNA, R. cantoniensis was most closely related to R. chinensis, and then to R. taciroi and R. silerifolius. The molecular phylogenetic relationships were not congruent with the previous report that R. cantoniensis was most closely related to R. silerifolius. In the sequence analysis of ITS and psbA-trnH, rps16, trnL for R. cantoniensis and the related taxa, R. cantoniensis showed polymorphism. It supported that the polymorphism also was reported in chromosome number and karyotype of R. cantoniensis. Ranunculus cantoniensis shared the marker gene of R. chinensis and R. silerifolius in ITS, and one of R. silerifolius in cpDNA. These results supported the hypothesis that R. cantoniensis was caused by hybridization between R. chinensis and R. silerifolius based on chromosome number and karyotype, and also estimated that R. silerifolius might be of maternal origin and R. chinensis be paternal.

• Journal of Aquaculture
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• v.7 no.4
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• pp.207-223
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• 1994

Induction of triploid cherry salmon, Oncorhynchus ma.sou was performed by the heat shock procedure. The triploids were induced by 15 and 20 min heat shock treatments after 10 min fertilization at $28^{\circ}C$. Incidences of the triploidy were $91.4\%\;and\;89.8\%$, respectively. Nucleus and erythrocyte from the induced triploids larger than those of the diploids in major axis, minor axis, major axis/minor axis, surface area and volume. The chromosome number of diploid was 2n= 66 (17 pairs of metacentrics or submetacentrics, 16 pairs of acrocentrics or telocentrics), and that of triploid was 3n=99. Satellites were observed in the short arm of the largest telocentrics, and these may be useful marker to determine the polyploidization. Diploid have outgrown to triploid, and female have also outgrown to male in the triploid group during the 22 months of observation period after hatching. During the spawning season, 22 to 26 months after hatching, diploid were observed the growth retardation because of their sexual maturation, however the triploid showed continuous growth.

• 한국균학회소식:학술대회논문집
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• 2015.05a
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• pp.41-41
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• 2015

BSA-seq technologies, combined Bulked Segregant Analysis (BSA) and Next-Generation Sequencing (NGS), are making it faster and more efficient to establish the association of agronomic traits with molecular markers or candidate genes, which is the requirement for marker-assisted selection in molecular breeding. Clubroot disease, caused by Plasmodiophora brassicae, is a serious threat to Brassica crops. Even we have breed new clubroot resistant varieties of Chinese cabbage (B. rapa ssp. pekinesis), the underlying genetic mechanism is unclear. In this study, an $F_2$ population of 340 plants were inoculated with P. brassicae from Xinye (Pathotype 2 on the differentials of Williams). Resistance phenotype segregation ratio for the populations fit a 3:1 (R:S) segregation model, consistent with a single dominant gene model. Super-BSA, using re-sequencing the parents, extremely R and S DNA pools with each 50 plants, revealed 3 potential candidate regions on the chromosome A03, with the most significant region falling between 24.30 Mb and 24.75 Mb. A linkage map with 31 markers in this region was constructed with several closely linked markers identified. A Major QTL for clubroot resistance, CRq, which was identified with the peak LOD score at 169.3, explaining 89.9% of the phenotypic variation. And we developed a new co-segregated InDel marker BrQ-2. Joint BSA-seq and traditional QTL analysis delimited CRq to an 250 kb genomic region, where four TIR-NBS-LRR genes (Bra019409, Bra019410, Bra019412 and Bra019413) clustered. The CR gene CRq and closely linked markers will be highly useful for breeding new resistant Chinese cabbage cultivars.

• Asian-Australasian Journal of Animal Sciences
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• v.25 no.12
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• pp.1649-1659
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• 2012

Crosses between Korean and Landrace pigs have revealed a large quantitative trait loci (QTL) region for fat deposition in a region (89 cM) of porcine chromosome 4 (SSC4). To more finely map this QTL region and identify candidate genes for this trait, comparative mapping of pig and human chromosomes was performed in the present study. A region in the human genome that corresponds to the porcine QTL region was identified in HSA1q21. Furthermore, the LMNA gene, which is tightly associated with fat augmentation in humans, was localized to this region. Radiation hybrid (RH) mapping using a Sus scrofa RH panel localized LMNA to a region of 90.3 cM in the porcine genome, distinct from microsatellite marker S0214 (87.3 cM). Two-point analysis showed that LMNA was linked to S0214, SW1996, and S0073 on SSC4 with logarithm (base 10) of odds scores of 20.98, 17.78, and 16.73, respectively. To clone the porcine LMNA gene and to delineate the genomic structure and sequences, including the 3'untranslated region (UTR), rapid amplification of cDNA ends was performed. The coding sequence of porcine LMNA consisted of 1,719 bp, flanked by a 5'UTR and a 3'UTR. Two synonymous single nucleotide polymorphisms (SNPs) were identified in exons 3 and 7. Association tests showed that the SNP located in exon 3 (A193A) was significantly associated with weight at 30 wks (p<0.01) and crude fat content (p<0.05). This association suggests that SNPs located in LMNA could be used for marker-assisted selection in pigs.

• Development and Reproduction
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• v.4 no.1
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• pp.79-85
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• 2000

This study was made to optimize the conditions needed to produce two types of gynogenetic diploids in the sweet fish, Plecoglossus altivelis. Firstly, ultraviolet (UV) ray doses between 3,000 erg to 14,000 erg/$\textrm{mm}^2$ were tested to inactivate sperm genetically. Based on the appearance of the haploid syndromes in the embryo, a dose of UV ray 6000~7000 erg was required to inactivate sperm genetically. Then, cold shock treatment at 1~2$^{\circ}C$ for 15~30 min were conducted to retain the 2nd polar body in inseminated egg. The best elapsed time before the start of the cold shock was examined between 5~8 min. The experiments in which began 5 min after insemination at 1~2$^{\circ}C$ during 17.5 min gave 21.2％ survival rate and 89.7% normal eyed embryo rate. The gynogenetic diploid produced by suppression of the first cleavage, a considerably high number of heteroploids appeared and high mortality was observed at the metamorphosis stage, so further investigation is needed. The production of gynogenetic diploids were confirmed by GPI isozyme marker. The heterozygous type in Gpi-1 locus was observed in the meiotic-G2N as a result of gene-centromere recombination during meiosis. The heterozygous type was never observed in mitotic-G2N and showed segregation into two homozygous types at Gpi-1 locus.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.10
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• pp.1389-1394
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• 2008

Abdominal fat characters are complex and economically important in the poultry industry. Their selection may benefit from the implementation of marker-assisted selection (MAS). The objective of this study was to identify the markers linked to QTL responsible for fatness traits. The Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) were used in the study. A total of 596 individuals from the divergent tails from the 6th to the 10th generations were genotyped at 23 microsatellite markers on chromosome 1. The differences of allele frequencies of all marker alleles between the divergent tails across the five generations were recorded. The allele frequencies of five markers, including LEI0209, LEI0146, MCW0036, ADL328 and MCW0115, had significant differences between the two tails in all five generations. The resulting p-values using Fisher's exact test on eleven markers, containing MCW248, MCW0010, MCW0106, LEI0252, LEI0068, MCW0018, MCW0061, LEI0088, MCW200, MCW283 and ROS0025, had a decreasing tendency from the 6th to the 10th generation. Statistical analysis showed that polymorphisms of the eight markers, including LEI0209, LEI0146, ROS0025, MCW0115, MCW0010, MCW0036, MCW283, ADL328, were significantly (p<0.0011) or suggestively (p<0.05) associated with abdominal fat content (AFW and AFP) across generations. It is concluded that the eight markers could be associated with the QTL affecting the deposition of abdominal fat in broiler chickens.

• Molecules and Cells
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• v.25 no.3
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• pp.417-427
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• 2008

Comparison of maps and QTLs between populations may provide us with a better understanding of molecular maps and the inheritance of traits. We developed and used two reciprocal $BC_1F_1$ populations, IP/DS//IP and IP/DS//DS, for QTL analysis. DS (Dasanbyeo) is a Korean tongil-type cultivar (derived from an indica x japonica cross and similar to indica in its genetic make-up) and IP (Ilpumbyeo) is a Korean japonica cultivar. We constructed two molecular linkage maps corresponding to each backcross population using 196 markers for each map. The length of each chromosome was longer in the IP/DS//IP population than in the IP/DS//DS population, indicating that more recombinants were produced in the IP/DS//IP population. Distorted segregation was observed for 44 and 19 marker loci for the IP/DS//IP and IP/DS//DS populations, respectively; these were mostly skewed in favor of the indica alleles. A total of 36 main effect QTLs (M-QTLs) and 15 digenic epistatic interactions (E-QTLs) were detected for the seven traits investigated. The phenotypic variation explained (PVE) by M-QTLs ranged from 3.4% to 88.2%. Total PVE of the M-QTLs for each trait was significantly higher than that of the E-QTLs. The total number of M-QTLs identified in the IP/DS//IP population was higher than in the IP/DS//DS population. However, the total PVE by the M-QTLs and E-QTLs together for each trait was similar in the two populations, suggesting that the two $BC_1F_1$ populations are equally useful for QTL analysis. Maps and QTLs in the two populations were compared. Eleven new QTLs were identified for SN, SF, GL, and GW in this study, and they will be valuable in marker-assisted selection, particularly for improving grain traits in tongil-type varieties.

• Journal of Life Science
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• v.17 no.11
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• pp.1505-1510
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• 2007

We found 8 single nucleotide polymorphisms (SNPs) in adipocyte fatty acid bonding protein (FABP4) gene as candidate gene of FAT1 locus on pig chromosome 4. With over 800 heads of major commercial pig breeds including Duroc, Landrace, Berkshire and Yorkshire, we analyzed SNPs of FABP4 gene to determine possible effects of FABP4 genotype to economically important traits. $400{\sim}800\;bp$ amplicons in FABP4 gene were used PCR-RFLP for each SNPs and we found that the frequency of some SNPs of this gene was different among the breeds. According to the statistical analyses to determine possible associations of each genotype with economic traits, it was found that subgroup with different genotypes showed significant differences in daily gain, backfat thickness, lean percentage and feed conversion ratio (P<0.05). Thus, as a Part of enhancing the selection competence related to swine growth rate and lean percentage, it is expected that FABP4 gene markers verified in this study will be useful to use for Korean commercial pig industry.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.338-341
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• 2009

"Hwaweon 1" was developed from an interspecific cross between Hwaseongbyeo and a wild species, Oryza rufipogon L. (IRGC 105491) based on marker-aided selection. The recurrent parent "Hwaseongbyeo" is a high grain quality cultivar with medium-maturity. Hwaweon 1 is nearly isogenic to Hwaseongbyeo except a small O. rufipogon introgression on chromosome 8 harboring the gene for grain weight. The preliminary and replicated yield trial was conducted at Chungnam National University in 2004, 2005 and 2006. The local adaptability test was carried out by the National Seed Management Office (NSMO) in 2007 and 2008. This cultivar was registered to NSMO with a cultivar designated as "Hwaweon 1". This cultivar averaged 89 cm in culm length and has a medium growth duration. This cultivar is resistant to stripe virus as the recurrent parent, Hwaseongbyeo. Milled rice of "Hwaweon 1" is translucent and the grain quality traits are comparable to those of the recurrent parent. The yield potential of "Hwaweon 1" in grain is about 7.43 MT/ha at the ordinary fertilizer level about 10% higher than that of Hwaseongbyeo mainly due to increase in grain weight.