• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.86-93
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• 2018

This present study was conducted to develop the domestic cultivation kit using water celery(Oenanthe Stolonifera DC.) seed. As the result of germination rates in 3 type inbred lines, the IT 232354 had the highest initial germination rate and final germination rate, and was selected as the inbred line to be used in the cultivation kit. The development of the domestic cultivation kit was carried out using the IT 232354 seeds. It was possible to cultivate up to 3 times harvest using the same root in this cultivation kit, though the growth decreased rapidly in the $4^{th}$ cultivation. As a result of investigating the effects of the type of nutrient solution on growth of water celery, the overall growth was the lowest in the nutrient solution for Oenanthe Stolonifera DC.(N.S.D.). The shoot growth was similar to that of nutrient solution for leaves and stem vegetables (N.S.L.S.) and amino acid fermentation by-product liquid (A.F.B.L.), however in the root growth, the N.S.L.S. was more effective than A.F.B.L. When it was harvested 4 times consecutively after 1 time of planting, the last survival ratio of A.F.B.L. was 100% while their ratios were 96.4% and 49.8% each for N.S.L.S. and N.S.D. For the growth by cultivation kit type, the hole type cultivation kit increased slightly compared to the 3 hole type cultivation kit in the $1^{st}$ and $2^{nd}$ harvest, but there was no difference in the $3^{rd}$ and $4^{th}$ harvest. Total yield of one cultivation kits showed the 3 hole type cultivation kit is much higher than the 2 hole type cultivation kit. According to the results of this experiment, it is possible to harvest three times by planting one times if it was cultivated using N.S.L.S. and A.F.B.L. in the 3 hole type cultivation kit.

• Journal of Plant Biotechnology
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• v.42 no.3
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• pp.215-222
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• 2015

The radish (Raphanus sativus L.) is an important Brassicaceae root vegetable crop worldwide. Several studies have been conducted concerning radish breeding. There are major challenges to prevent premature bolting in spring plantings. Here, we performed the characterization of two inbred radish lines which vary in bolting time. "Late bolting radish" (NH-JS1) and "early bolting radish" (NH-JS2) were generated by a conventional breeding approach. The two inbred lines showed different bolting phenotypes depending on vernalization time at $4^{\circ}C$. NH-JS1, the late bolting radish, was less sensitive to cold treatment and the less sensitivity was inversely proportional to the duration of the vernalization. We also measured gene expression levels of the major bolting time related genes in the NH-JS1 and NH-JS2 lines. RsFLC1 plays a central role in the timing of flowering initiation. It is a strong repressor and it's transcript is highly expressed in NH-JS1 compared to NH-JS2 under no treatment and vernalization conditions. RsFRI, a positive regulator of RsFLC, is also highly expressed in NH-JS1 compared to NH-JS2 regardless of vernalization. In contrast, RsSOC1, suppressed by FLC as a floral integrator gene, showed the most difference, a 5-fold increase, between NH-JS1 and NH-JS2 under vernalization conditions. From these results, we conclude that NH-JS1 showed a late flowering phenotype after cold treatment due to the expression differences of flowering time regulator genes rather than difference sensitivity to cold. These results may be useful to understand the control mechanisms of flowering time and may help identify molecular markers for selecting late bolting trait in radish.

• Journal of Plant Biotechnology
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• v.41 no.1
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• pp.56-63
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• 2014

Using commercial radish varieties for processing, about 30% of radish was discarded due to the root shape and low purity. To raise the processing ability, we tried to develop a new variety producing H-shaped root. As another characteristic required in variety for processing is high purity, we tried to raise purity using simple sequence repeats (SSR) markers for testing seed purity in every segregating generation. To develop Male-sterile (MS) seeding parent, we crossed commercial variety of 'Gwan dong spring' and 'Gyeo ryong spring'. One elite inbred was selected as recurrent parent for the MS plant. The major horticultural traits of selected inbred line were disease resistance, late bolting, heat resistance and bright green root top color. To develop pollen parent, we crossed commercial variety of 'Tae sang king' and 'Seoul spring'. We used individual selection method to develop H-shaped hard root and disease resistant inbred. In each segregating generation, we selected one plant based on phenotype and the uniformity of selected plant was tested by SSR markers using self-pollinated seeds. In the first segregating generation, 64.6% of sib plants shared the same band in PCR amplification using ACMP-490 primer and 66.7% using cnu-316 primer. The uniformity of segregating generations using ACMP-490 and cnu-316 raised in second generation to 68.8%, 70.8%, respectively; in third generation to 93.8%, 100%; in fourth generation to 93.8%, 100%; in fifth generation to 95.8%, 100%; in sixth generation to 100%, 100%. A novel cross was made using selected MS parent and pollen parent. When we checker the horticultural traits using autumn cultivation, the novel cross variety produced H-shaped root comparing other commercial varieties and produced highly uniform radish. Thus we registered this novel cross variety as 'YR ORE' at 2013 (Registration No. 4550).

• 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 Agricultural Science
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• v.34 no.2
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• pp.131-134
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• 2007

This study was carried out to identity the major characteristics of inbred lines and to develop early waxy colored hybrid at the Maize Genetics and Breeding Lab. in Chungnam National University. The eight colored waxy maize were planted on April 27, 2007 under Randomized Completely Block (RCB) Design with three replications. Stem height of IK1/H26-2 and Heunchal lines in this experiment were high as 196cm and 186cm compared to control as 156cm, respectively, while ear height of Local-2 and IK/LE were lower than that of check and ear diameter of IK/H26-1, IK/H26-2 and Local-2 were 10.3mm, 17.7mm and 18mm compared to control (21mm), respectively. Days to tasseling of Local-1, Local-2, and IK/LE lines were earlier than check. As a result of this experiment, the developed inbred lines were regard as useful germplasm for early hybrid development.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.3
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• pp.205-211
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• 2005

This study was carried out to construct cold-tolerance characteristics. The RILs were developed from progenies of a cross between cold-susceptible Tongil-type rice variety, Milyang 23 and cold-tolerant Japonica rice variety, Stejaree 45 by single seed descent methods. The 175 RILs $(F_8)$ were evaluated for cold tolerance traits by field screening under cold-water irrigation. Frequency distribution of RILs in leaf discoloration, heading delay, culm length reduction and number of spikelets reduction displayed nearly normal distributions with transgressive segregations to either side of parents, while the spikelet fertility reduction and panicle exsertion at low-temperature showed the more or less skewed continuous distribution toward the susceptible parent. Higher heritabilities over $60\%$ were observed in leaf discoloration, spikelet fertility reduction, panicle exsertion, while relatively lower heritabilities less than $40\%$ were observed in culm length reduction, number of spikelets reduction and grain yield reduction. Some cold-tolerance RILs were selected effectively by cold water irrigation, which are expected to be good materials in breeding program for cold tolerance.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.6
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• pp.489-494
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• 1993

The amount of maize being imported from other countries to meet the national demand are increasing every year. Regardless of the usage whether it is for silage or for human consumption, amount of seeds for farmers are ever being increased. In order to solve the problems arising from the seed import, a program for developing waxy hybrids with high quality was set up at the College of Agr., Chungnam National University. The main breeding targets for high quality waxy hybrids are focused on the pericarp thickness. In order to obtain basic information needed for developing hybrids with thin pericarp, six inbred lines all derived from open pollinated Korean waxy lines were diallel crossed. Results obtained indicate that waxy hybrids with thin pericarp can be developed by choosing proper parental lines. Of the six inbreds, Jewon inbred had utmost thin pericarp compared with other lines. Hybrids crossed with Jewon showed also thinner pericarp than other hybrids. However, Danyang which has thick pericarp showed thicker pericarp in hybrid combinations. Variance due to general combining abilities was greater than the variance due to the specific combining abilities, indicating that additive gene effects are more important. The pericarp thickness of waxy hybrid endosperm varied with the parts of pericarp. The germinal side of the pericarp is comparatively thinner than the abgerminal side. The upper part (crown) has thicker pericaip than lower part (tip) of the kernel.

• Korean Journal of Animal Reproduction
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• v.20 no.1
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• pp.53-61
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• 1996

This study was carried out to determine effectively the sex of rabbit embryos using H-Y antiserum. H-Y antiserum was obtained from inbred SD strain female rat which was immunized by injection of testis cell of inbred SD strain male rate into its spleen. The titer of antiserum was identified by sperm cytotoxicity test and culture of rabbit embryos with antiserum. The developed or undeveloped embryos were separated by exposure the embryos to the antiserum with H-Y antibody. Developed embryo were transferred to the recipients and sex of offspring were examined. 1. In the sperm cytotoxicity test, the rate of dead sperm showed no difference between two antisera from spleen and testis cell as antigens. It is confirmed that H-Y antibody in antiserum was absorbed by H-Y antigen in male rat spleen cells. 2. When rabbit morulae were exposed to antiserum and complement, the rate of embryos developed or arrested was 51 and 49% respectively and the rate was closely same as natural sex ratio of 50:50%. 3. When rabbit morulae were cultured for 12h in the medium containing antiserum produced by antigen of testis cell, the rate of embryos developed or arrested was 48 and 52% respectively and the rate was closely same as natural sex ratio of 50:50%. 4. Eighty rabbit embryos which were not affected by H-Y antiserum were transferred to four recipients. Two recipients were pregnant and born 13 pups among which 2 (14%) were male and 11 (86%) were female. In conclusion, existence of H-Y antibody in the serum from female rat immunized by injecting testis cell from newborn male rat to the spleen of the female rat was confirmed. When rabbitmorulae were exposed to H-Y antiserum and complement, about a half of embryos were developed to blastocysts. When the rabbit embryos not affected by H-Y antiserum were transferred, the rate of female offspring was 86%. Therefore, it was identified that most of embryos which were not affected by H-Y antiserum were female.

• Journal of Plant Biotechnology
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• v.34 no.1
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• pp.37-45
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• 2007

The genetic transformation of watermelon by Agrobacterium has been known very difficult and a few successful cases have been reported by obtaining the direct shoot formation. However, since this direct shoot formation is not guaranteed the stable transformation, the stable transformation with reproducibility is required by a different approach such as a callus induced manner. The best conditions for inducing the callus from cotyledon and root explants of watermelon were 2 mg/L zeatin + 0.1 mg/L IAA and 2 mg/L BA + 0.1 mg/L 2,4-D, respectively. The GFP expression in the callus was identified and monitored through fluorescent microscopy after transformation with pmGFP5-ER vector. Paromomycin rather than kanamycin was used for selecting the nptll gene expression because it was more effective to select the watermelon explants. Four different callus types were observed and the solid green callus showed stronger GFP expression. The highest frequency of GFP expression in the callus developed from cotyledon was 9.0% (WM8 inbred line), while the highest frequency from root was 8.3% (WM6 inbred line). The WMV-CP was transformed using the method of GFP transformation and the genetic transformation of WMV-CP was confirmed by PCR and Southern blot analysis. Here we present a system for callus induction of watermelon explant and the callus induced method would facilitate the establishment of stable watermelon transformation.