• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.3
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• pp.21-30
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• 1980

This is the fourth report in serial studies on the botanical characters of Korean maize lines collected. Several plant characters and genetical nature of lines were investigated and compared among selfed, sibbed and test crossed lines. Inbreeding depression and heterosis, and homozygosity expressed in percent were calculated. Throughout the study a great extent of variation of plant characters and genetical variation expressed in terms of inbreeding depression and heterosis were observed. The observed plant and genetic variation of plant characters were assumed to be enough for providing new breeding materials for future maize breeding program. The degree of homozygosity of Korean local maize lines suggested that a great portion of maize grown by Korean farmers presently are near or close to inbred and presumed to show a great heterosis when crossed to divergent lines.

• 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 CROP SCIENCE
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• v.60 no.4
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• pp.464-469
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• 2015

This study was carried out to find relationships of genetic distance and heterosis expression degree in the developed CNU waxy corn lines. The used material were developed in Corn Breeding Laboratory, Coll. of Agri. & Life Sci., CNU. Total 10 primers used for SSR maker analysis. In genetic distance, the used lines divided into four groups; A group has two lines, B group has one line, C group has ten lines and D group has eleven lines, respectively. Among used lines, CNU427 and CNU588 were very closed as a 74, while CNU451 and CNU429 were remote as a 40 inbred coefficient, respectively. While heterosis degree were very variable not only hybrids but also cross parents. Average heterosis of most cross-parent was high in plant height, ear height, flowering day and ear length. Especially, CNU H09-23 hybrid was high as 79.4% than other hybrids. Here, we gained the fact has closely relationship between genetic distance and heterosis.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.497-502
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• 2012

Since the year 2000, the production and consumption of broccoli have rapidly increased in Korea. And, the average production area and amount were about 1,700 ha and 29,000 ton for the past 5 years. Even with the increase of these cultivation and consumption, more than 95% of the broccoli seeds are currently imported from foreign countries such as Japan and Netherlands. Therefore, development of domestic broccoli varieties is needed to relieve Korean farmers' production cost for broccoli. In this situation, National Institute of Horticultural and Herbal Science (NIHHS) of Korea has tried to develop F1 hybrid varieties from elite lines that were obtained by microspore cultivation method from 2008. As the results, about 850 lines of broccoli were obtained and self-pollinated. Then their ploidy levels of the genome were confirmed to select double haploid (D.H.) lines. And the D.H. lines' horticultural traits were evaluated in open field. After the selection of 17 elite D.H. lines, they were cross-pollinated with a male sterile (MS) line to produce F1 hybrid seeds. After 2 to 3 years field trials of these F1 hybrid varieties at the area of Suwon, Gangneung, and Jeju respectively, two hybrid varieties such as 'Wongyo8011' and 'Wongyo8012' are selected for the application of variety protection. With these 4 years of research, we found that the microspore cultivation method is a powerful tool for the conventional breeding program, especially for the development of various inbred lines and even F1 hybrid varieties in short time.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.49-55
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• 2017

We investigated the callus induction and plant regeneration ability of 16 maize genotypes, including the Korean inbred lines, using 9 to 15 day-old immature zygotic embryos from maize grown in pots and from field cultures. Immature zygotic embryos placed on MS medium supplemented with L-proline 0.7 g/L, MES 0.5 g/L, Dicamba 1.5 mg/L, 2,4-D 0.5 mg/L, $AgNO_3$ 4 mg/L, and sucrose 20 g/L, showed the highest frequency of callus induction. The highest number of shoots regenerated when the embryogenic callus were transferred to MS medium supplemented with 5 mg/L zeatin. The root formation was observed when shoots were grown on MS medium supplemented with 0.2 mg/L indole-3-butyric acid (IBA). Additionally, under the same culture conditions, immature zygotic embryos from maize grown in the field also had a high frequency of plant regeneration. Except one genotype, 15 genotypes showed callus induction and shoot regeneration. Among the 16 genotypes tested, H99, B98, HW3, and B73 yielded the best plant regeneration. H99 showed maximum shoot formation from the primary embryogenic callus. The results suggest that genotypes and growth conditions of the maize plant plays very important roles for enhancing the embryogenesis competence of immature zygotic embryos. The successful regeneration from immature zygotic embryos of maize inbred lines provides a basis for molecular breeding of new cultivars by genetic transformation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.6
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• pp.539-545
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• 2004

The purpose of this study was to locate the quantitative trait loci (QTL) associated with quality properties in the recombinant inbred lines derived from the 'Milyang 23' and 'Gihobyeo' cross. Four quality-related traits; protein content, amylose content, fat acid content and sensory value were measured. Eight QTLs for protein content were detected on chromosomes 1 (two loci), 3, 6, 7 and 8 (three loci), each accounting for $6.0\%\~15.2\%$ of the phenotypic variation. Three QTLs for amylose content were detected on chromosomes 6 and 7 (two loci), each explaining from $7.3\%\;to\;24.4\%$ of the phenotypic variation. Six QTLs for fat acid content were detected on chromosomes 2 (two loci), 3, 6 (two loci) and 7, each explaining form $5.5\%\;to\;14.0\%$ of the phenotypic variation. Six QTLs for sensory value were detected on chromosomes 2, 6, 7(two loci) and 8 (two loci), each accounting for $5.5\%\~10.3\%$ of the phenotypic variation.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.833-836
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• 2013

'Hei' is a new cultivar of red with black flesh; originated from the cross of two inbred lines, mother plant, TKUI separated from 'Kame' in 2007 and father plant, TLB separated from tomato collected in Europe by pedigree breeding method. 'Hei' was tested for specific character and productivity of lines of tomatoes in spring for 2 years, 2008 to 2009. This variety had resistance to powdery mildew. 'Hei' is an indeterminate type. The fruit shape is round and the skin color is blackish red. The average fruit weight of 'Hei' is about 127.9 g and marketable yield is $5,715kg{\cdot}10a^{-1}$. Lycopene contents of 'Hei' are about $18.5mg{\cdot}100g^{-1}$, high compared with other tomato ($3.1mg{\cdot}100g^{-1}$). 'Hei' is suitable for environment-friendly protected cultivation because of resistance to powdery mildew.

• Journal of Life Science
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• v.17 no.5 s.85
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• pp.599-605
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• 2007

Seed and pod numbers are the main yield components in soybean. Selection for increased yield potential is main goal of plant breeding. The objective of this study was to identify quantitative trait loci(QTLs) that control pod number per plant, seed number per plant and pod in soybean. The 117 $F_{2:10}$ recombinant inbred lines(RILs) developed from a cross of 'Keunolkong' and 'Shinpaldalkong' were used. Two independent QTLs for pod number per plant were identified from linkage group(LG) F and L. Two QTLs for seed number per plant were located on LG F and L. Seed number per pod was related with three QTLs located on LG D1a, D1b and F. Pod and seed number per plant have two common QTLs on LG F and L.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.391-397
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• 1995

This study was carried out to investigate the characteristics of the seedling growth and nutrients uptake at 45 day seedlings in cytoplasmic genetic male sterile lines(HR7028A, IR54756A), their restore line (Yongmoonbyeo) and check variety (Changsungbyeo). Hybrid rices had longer and more roots, heavier dry weight and lower shoot /root ratio than their parents and inbred check variety, showing heterobeltiosis in absorbed amount of inorganic elements, content of total sugar, starch and chlorophyll in plant. Different magnitude of heterobeltiosis were shown between F$_1$ hybrid rices with the same restore line; HR7028A/Yongmoonbyeo had higher heterobeltiosis than IR54756A/Yongmoonbyeo did. Hybrid rices had more number and higher $\alpha$-naphthylamine oxidizing ability of newly-grown roots in 10 day sand culture in ground water with root-cut 45 day-seedling than parental lines and inbred variety. Nunber of the newly-grown roots were positively and significantly correlated with content of total sugar, starch and absorbed amount of inorganic elements in the shoot, and content of chlorophyll in the leaf.

• Korean Journal of Agricultural Science
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• v.28 no.1
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• pp.8-17
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• 2001

This study was carried out to obtain a basic intonation for the development of a new com hybird with tillers. Materials used in this study were 20 lines having three to four tillers per plant including the PI213749 U.S. line with non-tillers. These 20 lines were compared for the botanical characteristics and genetic distances were measured using RAPD analysis. Flowering date of the K15 was very earlier, while the K07 was very late in flowering date. Stem height and ear height were similar except for K04 and the K15. K06, K13 and K19 lines were appeared to be resistant to lodging due to decreased ear height. Number of tillers per plant of lines used were shown three to five on average. K09 showed the highest kernel yield, while the K08 was low. Among characteristics measured tiller per plant and flowering dates, and silking dates showed a positive correlation, while 100 kernels weight, flowering date and ear height were shown a negative with tillers per plant. A total of 17 bands by RAPD analysis using four per primer were appeared and these lines were classified into three groups, especially the third group could be classified into of four sub-groups.