• Animal Bioscience
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• v.36 no.6
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• pp.899-907
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• 2023

Objective: The better understanding of laying pattern of birds is crucial for developing breed-specific proper breeding scheme and management. Methods: Daily egg production until 50 wk of age of six chicken breeds including one layer (White Leghorn, WL), three dual-purpose (Rhode Island Red, RIR; Columbian Plymouth Rock, CR; and Barred Plymouth Rock, BR), one synthetic dwarf (DY), and one indigenous (Beijing-You Chicken, BYC) were used to characterize their clutch traits and egg production. The age at first egg, egg number, average and maximum clutch length, pause length, and number of clutches and pauses were calculated accordingly. Results: The egg number and average clutch length in WL, RIR, CR, and BR were higher than those in DY and BYC (p<0.01). The numbers of clutches and pauses, and pause length in WL, RIR, CR, and BR were lower than those in DY and BYC (p<0.01). The coefficient variations of clutch length in WL, RIR, CR, and BR (57.66%, 66.49%, 64.22%, and 55.35%, respectively) were higher than DY (41.84%) and BYC (36.29%), while the coefficient variations of egg number in WL, RIR, CR, and BR (9.10%, 9.97%, 10.82%, and 9.92%) were lower than DY (15.84%) and BYC (16.85%). The clutch length was positively correlated with egg number (r = 0.51 to 0.66; p<0.01), but not correlated with age at first egg in all breeds. Conclusion: The six breeds showed significant different clutch and egg production traits. Due to the selection history, the high and median productive layer breeds had higher clutch length than those of the less productive indigenous BYC. The clutch length is a proper selection criterion for further progress in egg production. The age at first egg, which is independent of clutch traits, is especially encouraged to be improved by selection in the BYC breed.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.21-21
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• 2017

Severe lodging has recurrently occurred at strong typhoon's hitting in recent climate change. The identification of quantitative trait loci (QTLs) and their responsible genes associated with a strong culm and their pyramiding are important for developing high-yielding varieties with a superior lodging resistance. To identify QTLs for lodging resistance, the tropical japonica line, Chugoku 117 and the improved indica variety, Habataki were selected as the donor parent, as these had thick and strong culms compared with the temperate japonica varieties in Japan such as Koshihikari. By using chromosome segment substitution lines (CSSLs) in which chromosome segments from the japonica variety were replaced to them from Habataki, we identified the QTLs for strong culm on chrs. 1 and 6, which were designated as STRONG CULM1 (SCM1) and STRONG CULM2 (SCM2), respectively. By using recombinant inbred lines (BILs) derived from a cross between Chugoku 117 and Koshihikari and introgression lines, we also identified the other QTLs for strong culm on chrs. 3 and 2, which were designated as STRONG CULM3 (SCM3) and STRONG CULM4 (SCM4), respectively. Candidate region of SCM1 includes Gn1 related to grain number. SCM2 was identical to APO1, a gene related to the control of panicle branch number, and SCM3 was identical to FC1, a strigolactone signaling associated gene, by performing fine mapping and positional cloning of these genes. To evaluate the effects of SCM1~SCM4 on lodging resistance, the Koshihiakri near isogenic line (NIL) with the introgressed SCM1 or SCM2 locus of Habataki (NIL-SCM1, NIL-SCM2) and the another Koshihikari NIL with the introgeressed SCM3 or SCM4 locus of Chugoku 117 (NIL-SCM3, NIL-SCM4) were developed. Then, we developed the pyramiding lines with double or triple combinations derived from step-by-step crosses among NIL-SCM1 NIL-SCM4. Triple pyramiding lines (NIL-SCM1+2+3, ~ NIL-SCM1+3+4) showed the largest culm diameter and the highest culm strength among the combinations and increased spikelet number due to the pleiotropic effects of these genes. Pyramiding of strong culm genes resulted in much increased culm thickness, culm strength and spikelet number due to their additive effect. SCM1 mainly contributed to enhance their pyramiding effect. These results in this study suggest the importance of identifying the combinations of superior alleles of strong culm genes among natural variation and pyramiding these genes for improving high-yielding varieties with a superior lodging resistance.

• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.72-72
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• 2017

We found a new stay-green mutant from 'Pyeongwon' which is an early-maturing rice variety in Korea. The mutant showed green leaves after grain ripening period and it maintained higher SPAD value than wild type rice plant and original variety 'Pyeongwon'. The stay-green trait in rice, three genes have been identified up to date. The non-yellow coloring1 (NYC1) gene encodes a chloroplast-localized short-chain dehydrogenase/reductase (SDR) with three transmembrane domains. The non-yellow coloring3 (NYC3) gene encodes a plastid-localizing alpha/beta hydrolase-fold family protein with an esterase/lipase motif. The Sgr gene encodes a novel chloroplast protein and regulates the destabilization of the light-harvesting chlorophyll binding protein (LHCP) complexes of the thylakoid membranes, which is a prerequisite event for the degradation of chlorophylls and LHCPs during senescence. After sequencing the PCR products, we found a single nucleotide variation($A{\rightarrow}T$) in the NYC1 gene, which changes the amino acid lysine to methionine. The NYC1 gene encodes a short-chain dehydrogenase/reductase(SDR) protein. And we confirmed the co-segregation between SNP and stay-green trait from genotyping the progenies of the mutant.

• 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 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.130-131
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• 2005

• The Korean Journal of Mycology
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• v.41 no.2
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• pp.91-96
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• 2013

Two strains Pleurotus eryngii 'Aeryni' and 'Na' carrying superior traits of a pileus and a earliness of harvest were selected to improve previously bred strains by single crosses. New hybrid, Aeryni 3 (Aeryni10 ${\times}$ Na5) showed superiority to other hybrids in yield, fruit body shape and days for harvest. The new strain, Aeryni 3 was harvested earlier than Keunneutari No. 2 by 2~3 days, and yielded 110.5 g/bottle (850 mL) which was 108% of that of Keunneutari No. 2. The ratio of diameter of pileus and stipe was 1.8 indicating that new stain will be likely low damage rate of fruit body during a distribution, and that was better than 2.1 of Keunneutari No. 2. A sensory test of taste of the new strain showed that 84.7% of evaluation panels selected "very good" while that of Keunneutari No. 2 was 55.5%. In purchasing intent test, 86.9% of panels will buy the new stain whereas 46.8% will buy Keunneutari No. 2 implicating that the new strain will likely be more marketability than previously bred strain.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.4
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• pp.494-500
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• 2019

Objective: Feed consumption contributes a large percentage for total production costs in the poultry industry. Detecting genes associated with feeding traits will be of benefit to improve our understanding of the molecular determinants for feed efficiency. The objective of this study was to identify candidate genes associated with feed conversion ratio (FCR) via genomewide association study (GWAS) using sequence data imputed from single nucleotide polymorphism (SNP) panel in a Chinese indigenous chicken population. Methods: A total of 435 Chinese indigenous chickens were phenotyped for FCR and were genotyped using a 600K SNP genotyping array. Twenty-four birds were selected for sequencing, and the 600K SNP panel data were imputed to whole sequence data with the 24 birds as the reference. The GWAS were performed with GEMMA software. Results: After quality control, 8,626,020 SNPs were used for sequence based GWAS, in which ten significant genomic regions were detected to be associated with FCR. Ten candidate genes, ubiquitin specific peptidase 44, leukotriene A4 hydrolase, ETS transcription factor, R-spondin 2, inhibitor of apoptosis protein 3, sosondowah ankyrin repeat domain family member D, calmodulin regulated spectrin associated protein family member 2, zinc finger and BTB domain containing 41, potassium sodium-activated channel subfamily T member 2, and member of RAS oncogene family were annotated. Several of them were within or near the reported FCR quantitative trait loci, and others were newly reported. Conclusion: Results from this study provide valuable prior information on chicken genomic breeding programs, and potentially improve our understanding of the molecular mechanism for feeding traits.

• Korean Journal of Plant Resources
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• v.34 no.4
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• pp.339-345
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• 2021

'Gondalbi' (Ligularia stenocephala (Maxim.) Matsum. & Koidz.) is the most cultivated Gomchwi species because of higher yield and low in aromatic flavor and bitter taste, But 'Gondalbi' is susceptible to powdery mildew disease and leaf shriveling after harvest in Summer. To improve powdery mildew disease resistance and post-harvest leaf shriveling problem in 'Gondalbi', 'Handeari-gomchwi' resistant to powdery mildew disease and having higher yield potential used as a paternal trait donor. Powdery mildew disease resistance and post-harvest leaf shriveling as well as agronomic performance of a new variety, 'Greenbear' were tested under field and green house conditions in Pyungchang, Korea from 2007 to 2016. Expression of both maternal and paternal characteristics in 'Greenbear' including purple colored petiole ears, glossy leaf and paternal, petiole trichome, absent at the back of a leaf were confirmed. Plant size and flowering time of 'Greenbear' were similar to check line, 'Gommany', while leaf number per plant and yield were higher in 'Greenbear'. 'Greenbear' has thinner leaves (0.66mm) compared to 'Gommany (0.69 mm)', and hardness appeared slightly higher in 'Greenbear(25.1 kg/cm²)'. The resistance to powdery mildew disease of the 'Greenbear' variety was slightly lower than that of the 'Gommany' variety, but somewhat showed high resistance.