• Proceedings of the Korean Society of Crop Science Conference
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• 2003.10a
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• pp.181-182
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• 2003

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.92-93
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• 2000

• 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.

• Plant Breeding and Biotechnology
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• v.6 no.4
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• pp.337-353
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• 2018

We used Illumina/HiSeq sequencing for analysis of gene expression profiling among four maize seed types (dent, CM3 and CM6; waxy, CM5 and CM19) at 10 DAP (days after pollination). A total of 88,993,000 (CM3), 103,817,340 (CM6), 103,139,640 (CM5), and 66,978,958 (CM19) sequence reads were generated with read lengths of about 0.9, 1.0, 1.0, and 0.7 billion bp, respectively. We obtained 69.1 (CM3), 71.0 (CM6), 71.2 (CM5), and 71.8% (CM19) high quality reads from the raw data and compared them with reference RNA sequences in a public DB (NCBI). It was revealed that mapped reads were 58%, 63%, 62%, and 62% of the EST reference in CM3, CM6, CM5 and CM19, respectively; and more than 51,000 genes were expressed based on RPKM criteria (over 0.25 value) in each CM3, CM6, CM5, and CM19 inbred line. In differentially expressed gene (DEG) analysis, we found that 3,527 genes were differentially expressed by at least two-fold with 1,709 upregulated in the two waxy inbred lines and 1,818 upregulated in the two dent inbred lines. We also detected genes for the sucrose and starch biosynthesis pathways based on BINs, and different expression patterns between waxy and dent inbred lines were shown for the gene set for starch synthesis, such as sh2, bt2, du1, wx1, and ae1. Although some genes were more expressed in dent lines, most genes for starch synthesis were much expressed in waxy lines. Especially, there was greater expression of the sus2 gene in both waxy lines compared with the dent lines.

• Korean journal of applied entomology
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• v.60 no.4
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• pp.431-448
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• 2021

We decided the efficient application timings of organo-synthetic insecticides for controlling the first generation larvae of O. furnacalis through investigations of insect stage-specific densities, damage aspects in maize, and effects of insecticides. A waxy maize cultivar, Ilmichal, was cultivated from April 20 (sowing) to July 26 (harvest, dough stage of maize) in Suwon, 2016. The maximum and 50% cumulative catch dates of the overwintering generation adults in the sex pheromone trapping were May 29 and May 31, respectively. Most of the first generation larvae finished their occurrence till the early reproductive stage of maize. The first generation larvae fed on leaves inside the whorl leaves before tassel and stem development of maize, sequentially moved to tassel and stem, and then moved finally to stem and ear parts. In the results of insecticide applications at different dates, the 9-11 leaf stage (June 10~17) and the 6-7 leaf stage (June 3) of maize were the most efficient application timings for direct spray of Etofenprox EC to maize, and for application of Carbofuran granules onto soil surface, respectively, which resulted in suppression of tunnelling damages. The timings for the two insecticides were 12-19 days and 5 days after the adult maximum catch date, respectively. Those timings after the 50% cumulative adult catch date were advanced 2 days.

• 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 Agricultural Science
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• v.28 no.2
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• pp.65-69
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• 2001

In order to evaluate the characteristics of growth and yield in $F_1$ waxy hybrids using Korean local maize lines, six hybrids including check, Chalok #1, were planted at the experinental field of the Chungnam National University. Stern and ear heights of $Yeonnong{\times}Jaerae$ and $FR805/IK_3{\times}Koryong$ hybrids were higher than the check hybrid. Number of tillers per plant in all hybrids were similar as 0.3 to 0.5 per plant. Ear length of waxy hybrids was longer than 15cm of check hybrid and ear diameter was also thicker than check except $FR805/IK_3{\times}Koryong$ waxy hybrid. A final result, $Yeonnong{\times}Jaerae$ among hybrids was comparatively superior to other hybrids in the test.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.3
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• pp.213-217
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• 2015

Soil moisture shortage can reduce yield of waxy corn because maize is one of the sensitive crops to the drought stress. Farmers cannot irrigate due to limited water resource and irrigating facilities although applying water is the most effective practice to solve the drought problem. The study was conducted to investigate the pre-treatment effect of salicylic acid on reducing drought damage of waxy corn (Zea mays L.). Salicylic acid at concentration of 0.2 mM was applied at seven-leaf stage or ten-leaf stage three times. Drought stress was imposed by withholding irrigation from 11 days before anthesis to 10 days after anthesis. Application of salicylic acid significantly increased ear length by 11.0~12.3% and yield by 8.8~11.3% compared with non-treated control, indicating that the drought injuries of waxy corn can be alleviated through pre-treatment of salicylic acid at the vegetative stage.

• 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.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.2
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• pp.175-184
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• 1995

In order to substitute sweet and super sweet maize hybrid seeds which are introduced at current, and to meet national demand for human consumption, inbreds and hybrids of waxy maize were developed by using Korean native lines, Six inbreds were used to produce 15 hybrids in a diallel cross, Six inbreds used were significantly different in tasseling dates, plant and ear heights, leaf area, and shank length, The inbred line, Bosung showed the longest shank length among the lines used, The ear characters like ear length and diameter, 100 kernel weight, row number, and kernel number per ear varied among lines, The inbred line Bosung was again significantly different from other lines in ear length and diameter, row number and 100 kernel weight. However, ]ewon had the highest kernel yield per 100. Hybrids were also different in plant and ear characteristics depending upon the inbreds used. The hybrids of Bosung showed the longest ear length and the heaviest kernel weight. Highest kernel yield per unit area was obtained by the hybrids crossed with Dangjin, The general combining ability(GCA) of Dangjin was found very effective in reducing plant and ear height of hybrids. The GCA of Jewon was very effective in increasing tiller number per plant. The inbred line Bosung was effective in increasing ear length and 100 kernel weight and in decreasing row number. The hybrid which showed the highest specific combining ability in ear length and 100 kernel weight was Jewon Chilbo.