• Korean Journal of Plant Resources
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• v.12 no.2
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• pp.161-165
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• 1999

The objective of this research was to find a useful genetic information for yield characteristics of tillering maize hybrids. Fls were planted under three plant densities at the experimental field of Agricultural College of Chungnam National University. The fresh yield of P1213749//FR805/IK3, FR805/IK3//Waesungri and IK/LE/FR805/IK3 was 7,862kg/10a, 8,290kg/10a and 7,746kg/10a, respectively. The fresh yield of tillering maize hybrids was higher than that of P3394 hybrids. The dry matter yield of P3394 hybrid was 1,430kg/10a with low plant density(4,800p1an1s) and that of PI213749//FR805/IK3 was 1,834kg/10a, the dry weight of FR805/IK3//Waesungri was 1,836kg/10a and that of IK/LE/FR805/IK3 was 1,810kg/10a. Grain yields per 10a of IK/LE//FR805/IK3(783kg) was the highest in 4,800plants/10a, and that of check hybrid was higher than the tillering maize hybrids in 3,600plants/10a, but grain yield per 10a of IK/LE/FR805/IK3 was 752kg, and that of P1213749/Dangjin//IK/LE(699kg) was higher than P3394 hybrid(680kg) with 2,400plants/10a.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.310-313
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• 2009

A single cross, Pyeonganok, is an yellow flint-like maize hybrid (Zea mays L.) developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2008. This hybrid, which has a high yield of dry matter was produced by crossing two inbred lines, KS140 and KS94. KS140 is the seed parent and KS94 is the pollen parent of Pyeonganok. Silking date of Pyeonganok is 3 days later than that of check hybrid, Kwangpyeongok. Stay-green of Pyeonganok is not greatly different with that of Kwangpyeongok. It has resistance to lodging. It has moderately resistance to Bipolaris maydis (southern corn leaf blight), Exserohilum turcicum (northern corn leaf blight), and corn borer but sensitivity to black streaked dwarf virus (BSDV). Pyeonganok was evaluated for the yields of dry matter at four locations from 2006 to 2008. The yields of Pyeonganok in dry matter was 20.84 ton/ha. Seed production of Pyeonganok has gone well due to a good match during crossing between the seed parent, KS140 and the pollen parent, KS94 in Yeongwol.

• Korean Journal of Breeding Science
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• v.51 no.2
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• pp.105-109
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• 2019

'Hwangdaok', a new maize F1 hybrid (Zea mays L.), was developed by the maize breeding team at the National Institute of Crop Science (NICS), RDA in 2016. The high-yielding yellow dent hybrid named 'Hwangdaok' was obtained by crossing between two inbred lines, 'KS203' and 'KS190'. After advanced yield trial in Suwon in 2012, regional yield trial was subsequently carried out to evaluate the growth and yield of 'Hwangdaok' at three different locations from 2014 to 2016. The number of days to silking of 'Hwangdaok' is 76. The plant height is 262 cm and ear height ratio is 51%, which are similar to those of 'Jangdaok'. It has resistance to lodging. The number of ears per 100 plants is 95. The ear length is 21.3 cm and weight of 100 seeds is 34.7 g, similar to those of 'Jangdaok'. It has moderate resistance to southern leaf blight (Bipolaris maydis) and European corn borer (Ostrinia nubilalis). The grain yield (10 ton/ha) of 'Hwangdaok' is 6% higher than that of 'Jangdaok'. The seed production rate of 'Hwangdaok' is acceptable due to good synchronization of flowering period during crossing between the seed parent, KS203, and the pollen parent, KS190, in Yeongwol. F1 seed yield was 1.68 ton/ha. 'Hwangdaok' can be a suitable cultivar to plain areas in Korea. (Variety registration No. 7502).

• Korean journal of applied entomology
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• v.17 no.4 s.37
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• pp.193-199
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• 1978

Five parents and their 10 $F_1$ crosses of maize (Zea mays L.) were tested by means of diallel analysis for the inheritance of peroxidase activity following Puccinia sorghi rust infection. Peroxidase activity was measured at day zero and at 2 days and 8 days after inoculation. Peroxidase activity was increased significantly by P. sorghi infection in all 15 genotypes after 8 days, but not after 2 days. Highly significant differences in peroxidase activity were detected among the 15 genotypes. The highly genera] resistant inbred, CM105, and its hybrids showed exceptionally high peroxidase activity in both healthy and infected plants. However, another highly resistant inbred, Oh545, showed exceptionally low peroxidase activity. Significant general combining ability (GCA) and specific combining ability (SCA) means quares were detected for peroxidase activity independent of disease. GCA mean spuares, however, were consistently a major contiribution to the inheritance of peroxidase activity in the infected plants whereas SCA men square contributions were minor. Rust resistant maize plants controlling mongenic dominant $Rp_1^d$gene showed stronger peroxidase reroxidase responses than their susceptible counterparts in the gel electrophoresis and densiometric tracings. The increased peroxidase activity occurred in both major leaf peroxidases, $Px_3\;and\; Px_7$.

• Journal of Animal Science and Technology
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• v.65 no.4
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• pp.792-803
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• 2023

This study aimed to assess the impact of weather events on the sorghum-sudangrass hybrid (Sorghum bicolor L.) cultivar production trend in the central inland region of Korea during the monsoon season, using time series analysis. The sorghum-sudangrass production data collected between 1988 and 2013 were compiled along with the production year's weather data. The growing degree days (GDD), accumulated rainfall, and sunshine duration were used to assess their impacts on forage production (kg/ha) trend. Conversely, GDD and accumulated rainfall had positive and negative effects on the trend of forage production, respectively. Meanwhile, weather events such as heavy rainfall and typhoon were also collected based on weather warnings as weather events in the Korean monsoon season. The impact of weather events did not affect forage production, even with the increasing frequency and intensity of heavy rainfall. Therefore, the trend of forage production for the sorghum-sudangrass hybrid was forecasted to slightly increase until 2045. The predicted forage production in 2045 will be 14,926 ± 6,657 kg/ha. It is likely that the damage by heavy rainfall and typhoons can be reduced through more frequent harvest against short-term single damage and a deeper extension of the root system against soil erosion and lodging. Therefore, in an environment that is rapidly changing due to climate change and extreme/abnormal weather, the cultivation of the sorghum-sudangrass hybrid would be advantageous in securing stable and robust forage production. Through this study, we propose the cultivation of sorghum-sudangrass hybrid as one of the alternative summer forage options to achieve stable forage production during the dynamically changing monsoon, in spite of rather lower nutrient value than that of maize (Zea mays L.).

• 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.66 no.4
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• pp.392-402
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• 2021

The present study investigated the effects of tillage practices (deep cultivation [DC] and conventional tillage [CT]) and extended planting dates (mid-June to July) for maize-onion rotation in paddy fields. The silage corn (Zea mays L.) cultivar 'Kwangpyeongok' and the waxy corn cultivar 'Ilmichal' were planted on June 14, July 3, and July 15 in 2019. In both maize, the plant height of June 14 planted was up to 100 cm greater than that of July 15 planted on August 16 and up to 40 cm on August 30. At 30 Days after planting, the leaf area index (LAI) of silage corn planted on July 3 and 15 greater than that of corn planted on June 14 due to high temperature in the early season; however, there were no differences in the LAI of waxy corn according to the planting date. Despite favorable temperature, plants sown on July 3 and 15 experienced high moisture stress during the seedling stage due to consistent rainfall, and waxy corn was highly sensitive to high moisture stress. The total yield of silage corn was 1,232 (845 in TDN), 860 (598 in TDN), and 765 (508 in TDN) DW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. The fresh marketable ear yield of waxy corn was 872, 814, and 525 FW kg·10a^-1 for plants sown on June 14, July 3, and July 15, respectively. After the completion of maize cultivation, onion seedlings (Allium cepa L.) were transplanted on November 12, 2019, and harvested on May 27, 2020. Neither summer tillage nor maize planting date affected onion growth or yield. The marketable onion yield was 8,305 and 7,848 kg·10a^-1 with DC and CT, respectively. In conclusion, DC did not improve maize growth or yield under paddy conditions. Mid-June to early July is a practical window for maize planting for growers in this region.

• Journal of Life Science
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• v.8 no.1
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• pp.8-13
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• 1998

The maize mitochondrial mutant (NCS2) is derived from homologous recombination between genes encoding NADH dehydrogenase subunit 4 and subunit 6. Plants from mitochondria mutants exhibited severe related growth and development including dwarfism and striping on the leaves. Aborted embryos from NCS2 mutants have been rescued and cultured on the N6 medium supplemented with 2,4-D 1 mg/l. Most calli from NCS2 aborted embryos showed slow growing pattern at first stage. However, upon continuous culturing them on the medium, those were segregated into mutant and normal callus lines. These segregations could be detected by using PCR method with three primers. Such segregation seems to be resulted from the preferential growth of normal cells over the mutant cells on the normal culture condition. Therefore, this method can be used for determining rate of indirect cytoplasmic segregation by estimating amplified band intensities. When NCS2 mutant callus lines cultured on regeneration medium, no adventitious shoot induction was observed. However, callus lines with more mitochondria induced adventitious shoots. These studies suggest that mitochondria NADH-dehydrogenase for electron transport in the inner membrane of mitochondria is essential for the differentiation and development of plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.11
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• pp.1316-1326
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• 2017

We evaluated the proximate compositions of raw materials, total polyphenols, total flavonoids, and radical scavenging activities of roasted maize tea according to cultivation period and variety. Proximate compositions of raw materials were significantly different according to cultivation period and variety, and quality characteristics of roasted maize tea extracts were significantly different according to cultivation period. Total polyphenols, total flavonoids, and radical scavenging activities of roasted maize tea were significantly different before and after roasting. The total polyphenol content of Pyeonggangok cultivar sown on April 5th was elevated about 3.60-fold before and after roasting by $3.42{\pm}0.16$ and $12.22{\pm}0.67mg$ gallic acid equivalents/g, respectively. Overall, total polyphenol content was higher in roasted maize tea produced using maize sown on April 5th. 1,1-Diphenyl-2-picrylhydrazyl radical scavenging activity of Gangdaok cultivar sown on April 5th was elevated about 31.6-fold before and after roasting by $7.61{\pm}1.93$ and $240.37{\pm}8.82mg$ Trolox equivalents (TE)/g, respectively. 2,2'-Azino-bis-3-ethylbenzothiazoline-6-sulfonic acid radical scavenging activity of Pyeonggangok cultivar sown on April 5th was elevated about 5.5-fold before and after roasting by $153.84{\pm}1.32$ and $843.54{\pm}3.64mg$ TE/g, respectively. The correlation between proximate compositions of raw materials and quality as well as antioxidant characteristics of roasted maize tea showed overall significance.

• Korean Journal of Agricultural Science
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• v.15 no.2
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• pp.123-131
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• 1988

This study was done to investigate the interplanting effects of corn, when a corn hybrid with tillers (IK derivaties) was interplanted with a corn hybrid without tillers(Jinjoo Ok). The interplanting ratios of two hybrids, IK and Jinjoo Ok, were 1 to 1, 1 to 2, 1 to 3, 2 to 1, and 3 to 1. The interp1anting effects were compared with monoculture for major agronomic characteristics. 1. The plant height was increased when interplanted regardless of the interplanting ratios of the two hybrids. The general growth of IK hybrid was a little hindered when the interplanting ratio of Jinjoo Ok hybrid increased. 2. The number of tillers produced by the IK hybrid increased until 40 days after emergence and appeared to increase as the interplanting ratio of IK hybrid increased. 3. When monocultured, the fresh weight of IK hybrid per 10a was 8,096kg and and 6,677kg at silking and dough stages, respectively and these were 77%, 53% over the fresh weight of Jinjoo Ok at the sarne stages. When IK and Jinjoo Ok hybrids were interplanted in 1 to 1 ratio, the fresh weight of IK was 20% higher than that of Jinjoo Ok monocultured. 4. The highest grain yield per 10a was obtained from the Jinjoo Ok hybrid monocultured and the yield was 434kg. Even the interplanting ratios between IK and Jinjoo Ok were 1 to 1 and 1 to 3, the grain yield of Jinjoo Ok was 16% and 13% over the IK, respectively. 5. Root and stalk lodging of IK hybrid was 29% when monocultured and seemed to increase as the interplanting ratio of Jinjoo Ok increased. The lowest lodging was found when the interplanting ratio of IK and Jinjoo Ok was 1 to 1. 6. Stem diameter of IK hybrid was also decreased as the interplanting ratio of Jinjoo Ok increased. The ear height of IK was lowered as the interplanting ratio of IK was increased. The two hybrids tested seemed to have tolerance to the black streaked dwarf virus(BSDV).