• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.107-107
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• 2017

Sweet corns are enjoyed worldwide as processed products and fresh ears. Types of sweet corn are based on the gene(s) involved. The oldest sweet corn type has a gene called "sugary (su)". Sugary-based sweet corn was typically named "sweet corn". With its relatively short shelf life and the discovery of a complementary gene, "sugary enhanced (se)", the sweet corn (su only) was rapidly replaced with another type of sweet corns, sugary enhanced sweet corn, which has recessive homozygous su/su, se/se genotype. With the incorporation of se/se genotype into existing su/su genotype, sugary enhanced sweet corn has better shelf life and increased sweetness while maintaining its creamy texture due to high level of water soluble polysaccharide, phytoglycogen. Super sweet corn as the name implies has higher level of sweetness and better shelf life than sugary enhanced sweet corn due to "shrunken2 (sh2)" gene although there's no creamy texture of su-based sweet corns. Distinction between sh2/sh2 and su/su genotypes in seeds is phenotypically possible. The Involvement of se/se genotype under su/su genotype, however, is visually impossible. The genotype sh2/sh2 is also phenotypically epistatic to su/su genotype when both genotypes are present in an individual, meaning the seed shape for double recessive sh2/sh2 su/su genotype is much the same as sh2/sh2 +/+ genotype. Hence, identifying the double and triple recessive homozygous genotypes from su, se and sh2 genes involves a testcross to single recessive genotype, chemical analysis or DNA-based marker development. For these reasons, sweetcorn breeders were hastened to put them together into one cultivar. This, however, appears to be no longer the case. Sweet corn companies began to sell their sweet corn hybrids with different combinations of abovementioned three genes under a few different trademarks or genetic codes, i.g. Sweet $Breed^{TM}$, Sweet $Gene^{TM}$, Synergistic corn, Augmented Supersweet corn. A total of 49 commercial sweet corn F1 hybrids with B73 as a check were genotyped using DNA-based markers. The genotype of field corn inbred B73 was +/+ +/+ +/+ for su, se and sh2 as expected. All twelve sugary enhanced sweet corn hybrids had the genotype of su/su se/se +/+. Of sixteen synergistic hybrids, thirteen cultivars had su/su se/se sh2/+ genotype while the genotype of two hybrids and the remaining one hybrid was su/su se/+ sh2/+, and su/su +/+ sh2/+, respectively. The synergistic hybrids all were recessive homozygous for su gene and heterozygous for sh2 gene. Among the fifteen augmented supersweet hybrids, only one hybrid was triple recessive homozygous (su/su se/se sh2/sh2). All the other hybrids had su/su se/+ sh2/sh2 for one hybrid, su/su +/+ sh2/sh2 for three hybrids, su/+ se/se sh2/sh2 for three hybrids, su/+ se/+ sh2/sh2 for four hybrids, and su/+ +/+ sh2/sh2 for three hybrids, respectively. What was believed to be a classic super sweet corn hybrids also had various genotypic combination. There were only two hybrids that turned out to be single recessive sh2 homozygous (+/+ +/+ sh2/sh2) while all the other five hybrids could be classified as one of augmented supersweet genotypes. Implication of the results for extension service and sweet corn breeding will be discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.626-631
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• 1997

This study was conducted to clarify the genetic effect on the duration of grain filling with using the eight corn inbreds. In diallel cross analysis, the grain filling during the lag period showed partial dominance with great additive effects. Inbreds FR14A and A508 showed greater recessive gene effects for lag period, while FR25 showed greater effects of dominant genes. The genetic analysis for the effective filling period(EFP) showed over dominance without additive gene effects. FR25 of 8 inbreds showed greatest effects of dominant genes for EFP, while YUBC208 showed greater recessive gene effects for EFP than other inbreds. The genetic analysis for total grain filling period(TGFP) seemed to be due to partial dominance with greater additive effects. Early inbred line, YUBC208 especially showed greater recessive gene effects for TGFP than others. No. of effective genes related to EFP and TGFP were estimated by at least 5.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.2
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• pp.142-146
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• 1989

Anther and/or tissue culture of cross pollinated crops would be very important because it can result in the direct use of haploids or doubled haploids for developing superior hybrids or varieties. The objective of the study was to investigate the response frequencies in anther and/or tissue-cultured hybrids of corn. pearl millet and buckwheat to identify agronomically acceptable germplasm of the crops. 27 crosses of corn inbred lines were evaluated by plating their anthers on N6. MS and Yu-Pei media. Two genotypes of FR1l41/FR16 hybrid cultured on N6 medium and Fla 2BT73/S6013 hybrid cultured on N6 medium responded with one anther producing calli when plated after 5$^{\circ}C$ low temperature treatment for one week. Immature embryos of corn hybrid Suwon 19 responded producing calli that were regenerated to plants at a 8.6 percent success rate. Of the 20 corn hybrids. immature tessels of FR1l41/FR16. B68/A1l6N//KS15. KS16/KS17. GA209/DB578 and SDB126/GA209 crosses responded at a relatively higher success rate producing calli that were regenerated to plants. In tissue culture of elongating culms of pearl millet x Napier grass interspecific hybrid. 2.5-4.0mm long pieces of the culm were good for callus induction resulting in higher success rate. The epicotyl of buckwheat was very good for tissue culture. and the node produced the plants regenerated directly without callus induction on the B5 medium containing I ppm BA and 0.05 ppm IBA. There were great differences in response to anther and/or tissue culture of corn, pearl millet and buckwheat due to genotype x medium and environment interactions.

• Korean Journal of Plant Resources
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• v.22 no.4
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• pp.323-329
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• 2009

In order to find out superior corn line which has a strong antioxidant activity in the corn silk, antioxidant compounds and antioxidant activity were measured from various inbred and F1 lines. As a result, the contents of phenolic and flavonoid compounds range from 532 mg/100 g to 3,274 mg/100 g and from 980 mg/100 g to 2,420 mg/100 g respectively. Absorbance at 517 nm for contents of anthocyanins ranges from 0.05 to 0.76. Correlation coefficients between antioxidant compounds and various antioxidant assays such as DPPH, ABTS and FRAP were analyzed. Correlation coefficients between antioxidant activity and phenolic compounds and anthocyanin were significantly high in ABTS and FRAP assays. Considering acidic extraction condition and intervention between anthocyanins and DPPH solution, ABTS assay and FRAP assay are more suitable methods to evaluate antioxidant activity of corn silks. Especially, ABTS assay is thought to be the best method among three assays because the antioxidant activity in ABTS assay showed high correlation with phenol, flavonoid and anthocyanin compounds respectively. Among the samples, S15 which showed the highest contents of total phenolic compounds and the most potent antioxidant activity in ABTS and FRAP assay will be a good source for functional material.

• Journal of agriculture & life science
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• v.51 no.1
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• pp.35-43
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• 2017

This research was carried out to excessive water tolerance test among corn accessions collected from India to breed corn cultivars targeting India market. The corn accessions were 20 Inbred lines and cultivars from India as well as Korean cultivars Gwangpyungok and Chaloksusu. Excessive water tolerance test was done in the green house by immerging the pots containing corn seedlings for two weeks. Then, the plant heights were measured to compare the control plants that were not grown in the immerging state. The results showed that seven accessions of high tolerance in flooding; H2(92.9%), H18(88.8%), CN114A(98.1%), CN351A(94.3%), Super900M(95.3%), P3394(98.8%), 31N27(96.7%) in which the percent is comparison to the control plants. Whereas nine accessions showed high damage by immerging; H1(78.9%), H8(73.4%), H10(77.1%), H19(79.0%), H26(74.1%), H31(75.7%), H34(77.5%), H36(77.4%), H40(74.6%). However, the reduction on the contents of chlorophyll a, chlorophyll b, carotenoids in leaf revealed contrast results to the flooding tolerance. Particularly, H36($7.249{\mu}g{\cdot}mg^{-1}$) and H40($7.642{\mu}g{\cdot}mg^{-1}$) showed rapid reduction in the chlorophyll a content during the flooding treatment. Whereas two Indian commercial varieties 37N27($0.630{\mu}g{\cdot}mg^{-1}$) and P3394($1.208{\mu}g{\cdot}mg^{-1}$) showed slight reduction. The reduction of chlorophyll a and carotenoid contents was positively correlated during the excessive water stress.

• 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 Breeding Science
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• v.41 no.4
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• pp.599-602
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• 2009

A single cross hybrid, Heukjinjuchal, is a black color waxy corn (Zea mays L.) developed by the maize breeding team at NICS in 2008. Heukjinjuchal was produced by crossing two inbred lines, KBW24 as seed parent and KBW2 as pollen parent. Ear length and ear diameter of Heukjinjuchal was 16.0 cm and 4.4 cm, respectively. The ratio of kernel set length/ear length was 89%, similar with that of a check hybrid, Chalok1. It is resistant to Northern corn leaf blight disease and also lodging tolerant. Fresh ear yield of Heukjinjuchal comparable with those of a check hybrid, Chalok1 in regional yield trials for three years. Seed production of this hybrid is relatively easy because of well overlapping period of silking and pollen dispersal between the two parents. This cultivar would be well adaptable to the whole country.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.1
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• pp.48-53
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• 1988

Pearl millet has been detected as a promising new forage crop of excellent quality and productivity since 1985. Its green fodder yields were 10.7 to 12.8 tons per hectare in average of 26 accessions in Suwon, 1985. The yield level was much higher than those of Italian and pro so millets and com. Com was better than Italian and proso millets, and proso millet was better than Italian millet for a green fodder crop. Suwon 1 pearl millet hybrid was the best of the 13 hybrids examined in Suwon, 1986 being 149 tons per hectare of three times cut green fodder yields. The pearl millet hybrid was higher in green fodder yield than com and sorghum/sudan grass hybrids. Leaf area index was 32.4 for the three times cut pearl millet, while 5.8 for the one time cut corn, and 20.8 for the three times cut sorghum/sudan grass. Crude protein content was 16.3 percent for pearl millet being six to five percent higher than corn and sorghum/sudan grass, 11.8 percent for the one time cut at maturity and 16.1 percent for four times cut being higher than corn and sorghum/sudan grass. Crude fat content was 3. percent for pear 1 millet grain being some what higher than corn and sorghum/sudan grass and 1.3-1.4 percent for green fodder crop. Crude fiber content in grain was 1.9 percent for pearl millet 2.6 percent for corn, and 4.3 percent for sorghum/sudan grass. Crude fiber content in pearl millet plant was 24.4 to 26.8 percent, Crude ash content was 2.4 percent in grain and 10.8 to 11.6 percent in the plants of pearl millet hybrid. In vitro digestibility of grain was 93.7 percent for pearl millet, 95.4 percent for corn, and 55.8 percent for sorghum/sudan grass. The digestibility of whole plant was 57.6 to 63.4 percent for pearl millet, 46.3 percent for corn, and 47.3 to 57.6 percent for sorghum/sudan grass. Heavier nitrogen fertilizer applications increased green fodder yields, protein content and digestibility, but reduced fat and ash content of pearl millet inbred line T 186.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.5
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• pp.361-367
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• 2002

In order to determine the optimum harvest time for the seed production of inbreds and hybrids in silage corn, the ears of sib-pollinated 'KS5', 'KS7rhm', and 'Ga209' and cross-pollinated 'KS5' $\times$ 'KS6' (Suwon19), 'KS7 rhm' $\times$ 'KSl17' (Suwonok), and 'Ga209' $\times$ 'DB544'(Kwanganok) were harvested at the one-week intervals from 4 to 10 weeks after silking. The optimum harvest time for the seed production for 'KS5', 'KS5' $\times$ 'KS6', 'KS7 rhm', and 'KS7rhm' $\times$ 'KS117' was 7 weeks after silking considering both emergence rate and plumule growth in cold test. Although earlier harvested seeds showed similar germination rate as the seeds harvested at the optimum time at $25^{\circ}C$, their emergence rate were lower in cold test. Seed weight and $\alpha$-amylase activity of earlier harvested seeds were lower compared to those of seeds harvested at the optimum time, while leakage of total sugars and electrolytes were higher. However, the later harvested seeds showed lower germination rates at $25^{\circ}C$ and emergence rates in cold test probably due to the lower $\alpha$-amylase activity although they showed increased seed weight and reduced leakage of total sugars and electrolytes. In contrast, the emergence rate of 'Ga209' and 'Ga209' $\times$ 'DB544' in cold test increased up to 10 weeks after silking probably due to the increased seed weight and $\alpha$-amylase activity and reduced sugar and electrolyte leakages during the germination. The cross-pollinated F$_1$ hybrid seeds showed higher germination and emergence rates at $25^{\circ}C$ and in cold test, and higher plumule growth and $\alpha$-amylase activity compared to those of sib-pollinated inbreds.

• Journal of The Korean Society of Grassland and Forage Science
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• v.33 no.1
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• pp.1-5
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• 2013

Andaok, a new single cross variety, is a yellow dent maize hybrid (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2011. This hybrid, which has a high yield of grain, was produced by crossing two inbred lines, KS161 and KS162. KS161 is the seed parent and KS162 is the pollen parent of Andaok. Silking date of Andaok is 3 days later than that of the check hybrid, Jangdaok. Plant height of Andaok is longer than that of Jangdaok. Ear numbers per 100 plants of Andaok is more than that of Jangdaok. Ear length of Andaok is shorter than that of Jangdaok. The weight of 100 seeds of Andaok is heavier than that of Jangdaok. It has moderate resistance to southern corn leaf blight (Bipolaris maydis), black streaked dwarf virus (BSDV) and corn borer. It has strong resistance to northern corn leaf blight (Exserohilum turcicum). It has resistance to lodging. Andaok was evaluated for its yield of grain at three locations from 2009 to 2011. The grain yield of Andaok was 7.80 ton/ha. Seed production of Andaok has gone well due to a good match during crossing between the seed parent, KS161, and the pollen parent, KS162, in Yeongwol.