• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.473-480
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• 1983

To obtain basic information on the Korean local com lines a total of 57 lines were selected from 1,000 Korean local collection at Chungnam National University, and classified by principal component analysis, and genetic nature was investigated. There were a great variation in mean values of plant characters of the lines. The mean values of plant characters except for density of kernels varied with types of crossing. All characters except for tasselling dates were reduced in magnitude when selfed, while those characters were increased when topcrossed. The inbreeding depression varied with plant characters and lines. The characters such as yield, kernel weight per ear, ear weight and plant height showed great degree of inbreeding depression. Group I showed high inbreeding depression in such characters as 100 kernel weight, leaf number, plant height and days to tasselling, while group II showed high inbreeding depression in other plant characters. Heterosis of plant characters varied also with lines. The ear weight, kernel weight per ear, yield, 100 kernel weight, and plant height were some of the plant characters showing high heterosis. Group II showed high values of heterosis in such characters as ear length, ear diameter, ear weight, kernel weight per ear, 100 kernel weight and leaf length, while group I was high in heterosis in other plant characters. The degree of homozygosity was highest in ear weight (79.1%) and lowest in ear number per plant (-2.1%). Group II showed higher degree of homozygosity than group I. Correlation coefficients between characters of sibbed and topcrossed lines were positive for all characters. Highly significant correlation coefficients between sibbed and topcrossed lines were obtained especially for characters such as ear number per plant, plant height, leaf length and yield per plot.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.215-228
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• 1977

In order to provide good germplasm for developing good corn hybrids, a total of 948 Korean indigenous corn lines were collected from various parts of country and major morphological characterstics of ears were investigated. The results obtained were as follows; 1) Ear Type; From the east-north mountaionus region where more than 80% of total corn production is practiced, cylinder (type I) or similar types to cylinder corn were collected, and from the southern plain region, where rather small scales of corn is grown, cone type (type IV) or similar types to cone were prevalent. 2) Kernel color; In the ear colors of all the indigenous corn lines collected from ten regions, ears with mono color were 54.4%, ears with two color mixed were 39.0% and ears with three or more color mixed were 6.6%. In northern mountainous region, region A and region I, ear color was mostly white or white plus other colors, while in other regions ear color was yellow or yellow plus other colors. 3) Denting; Dent type was only 4.3% of Korean indigenous corn lines collected, and others were flint type. Dent type was collected from northern regions, where foreign corn varieties were introduced and grown. 4) Ear row number; Ear row numbers of indigenous corn lines collected were 12 to 16. There was no significant differences among the ear row numbers in a ear ciassified by regions. However, it was observed that ear row number was closely related to kernel size. For instance, the ears with 24 ear-rows were the smallest in kernel size. 5) Quality of starch; 70.9% of the indigenous corn lines collected were kernels with hard starch. Corn with soft starch was 26.0% and medium type was 3.1%. In region A and region I, where lot of corn is grown, corn with hard starch was more frequently collected. 6) Pop corn and waxy corn; In all the indigenous corn lines collected, popcorn was distributed uniformly through the regions except region I, and waxy corn was found more in the northern mountainous region. 7) Ear length; The mean ear length of indigenous corn lines collected was 13cm. In region A and region I ear length was larger than that in other regions. 8) Ear diameter; The mean ear diameter of indigenous corn lines collected was 3.3cm. In region A and region I ear diameter was larger than that in other regions. 9) Kernel length, kernel width and kernel thickness; The mean kernel length, kernel width and kernel thickness of indigenous corn lines collected were 0.82cm, 0.42cm, and 0.78cm, respectively. The kernel size in the region A and region I was larger than that in other regions. 10) Ear weight; The mean ear weight of indigenous corn lines collected was 58.04gr. Ear weight was remarkably heavier in region A and region I. The heaviest ear weighed 330gr, and the lightest ear weighed 5 gr. 11) Kernel weight of a ear and 100 kernel weight; Kernel weight of a ear and 100 kernel of indigenous corn lines collected were 47.07gr and 15.07gr, respectively. Kernel weights and 100 kernel weights were much heavier in region A and region I than other regions.

• Journal of Animal Environmental Science
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• v.12 no.2
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• pp.61-66
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• 2006

This study was carried out to investigate the relationship between the physical dimensions of ear and age for swine. The physical dimensions of ear and weight for twenty pigs were investigated on 1, 20, 40, 90, 120, and 150 days of age, respectively. The thickness of ear was measured at the upper, middle, and lower part of fore perimeter, and the middle and lower part of hind perimeter. The length of ear was measured for width and height. The thickness of ear increased rapidly from 1 day to 20 days of age, then it developed gradually after that period of time. The thickness at the lower part of fore perimeter increased most rapidly from 1 day to 20 days of age. In the length of ear, width increased gradually whereas height increased rapidly from 1 day to 90 days of age and then they almost did not. All the regression equations between the physical dimensions of ear and age were best represented by $Y=a+b\;X^{0.5}$. These results suggest that RFID has to be installed on the middle part of hind perimeter and an ID chip has to be installed on the lower part of fore perimeter.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.3
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• pp.267-273
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• 2013

We evaluated the morphological characteristics of 79 popcorn inbred lines, which were developed to breeding popcorn variety at Maize Experiment Station, Gangwon Agricultural Research and Extension Services, by examining ten quantitative and three qualitative characteristics. In the survey of 3 qualitative traits for 79 popcorn inbred lines, most inbred lines respectively showed purple (46 inbred lines) at tassel color (QL1), green (55inbred lines) at silk color (QL2) and green (75 inbred lines) at stem color (QL3). While, on the survey of 10 quantitative traits among 79 popcorn inbred lines, they showed the morphological variation in plant height (QN1, $174.2{\pm}34.9$ cm), ear height (QN2, $103.4{\pm}24.7$ cm), ear length (QN3, $9.4{\pm}3.0$ cm), kernel setting length (QN4, $8.4{\pm}2.6$ cm), ear thickness (QN5, $24.9{\pm}7.7$ mm), ear row number (QN6, $14.0{\pm}2.3$ number), ear weight (QN7, $36.5{\pm}26.0$ g), kernel weight (QN8, $30.9{\pm}19.3$ g), 100 kernel weight (QN9, $10.4{\pm}3.8$ g) and germination rate (QN10, $95.3{\pm}8.1%$), respectively. As a result, 5 inbred lines (PS0-001, PS0-003, PS1-002, PS1-003, PS2-009) in the 79 popcorn inbred lines have showed comparatively high values for the five quantitative traits. On the principal component analysis, silk color (QL2), ear length (QN3), kernel setting length (QN4), ear thickness (QN5), ear weight (QN7), kernel weight (QN8) and 100 kernel weight (QN9) greatly contributed in positive direction on the first principal components, whereas tassel color (QL1), stem color (QL3), ear height (QN2) and ear row number (QN6) contributed in negative direction on the first principal component. In addition, plant height (QN1), ear height (QN2), and kernel weight (QN8) contributed in positive direction on the second principal component, and also tassel color (QL1), silk color (QL2), ear length (QN3), ear row number (QN6) and 100 kernel weight (QN9) contributed in negative direction on the second principal component.

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.120-120
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• 2020

Based on the simple sequence repeat (SSR) marker, a Korean wheat core collection were established with 616 wheat accessions. Among them, the SNP genotyping for the entire genome was performed using DNA chip array to clarify the whole genome SNP profiles. Consequently, a total of 35,143 SNPs were found and we re-established a mini-core collection with 247 accessions. Population diversity and phylogenetic analysis revealed genetic diversity and relationships from the mini core set. In addition, genome-wide association study (GWAS) was performed on 19 phenotypic traits; ear type, awn length, culm length, ear length, awn color, seed coat color, culm color, ear color, loading, leaf length, leaf width, seeding stand, cold damage, weight, auricle, plant type, heading stage, maturation period, upright habit, and degree of flag leaf. The GWAS was performed using the fixed and random model circulating probability unification (FarmCPU), which identified 14 to 258 SNP loci related to 19 phenotypic traits. Our study indicates that this Korean wheat mini-core collection is a set of germplasm useful for basic and applied research with the aim of understanding and exploiting the genetic diversity of Korean wheat varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.4
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• pp.477-484
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• 2020

This study was conducted to investigate the effects of slow-releasing fertilizer and sowing date on waxy corn propagated through double cropping without tillage. "Mibaek 2" was sown for first cropping on March 25^th, April 5^th, and April 15^th, and for second cropping on July 5^th, July 15^th, and July 25^th in 2018-2019. In order to save labor, slow-releasing fertilizer was utilized only one time before sowing. The accumulated temperature from sowing to silking was about 590-700℃. It took 65-77 days when "Mibaek 2" was sown in early April, but the one sown in early July took 42-52 days. In the first cropping, the culm length and ear length caused by the sowing date had no statistical significance, but the kernel set length was the highest at 123 cm in the sowing district on April 5^th. The weight of marketable ears was the highest at 100%, in addition to soil testing-based recommended fertilization. Meanwhile, in the second cropping, culm length, ear length, and yield were less compared to the first cropping. The culm length, kernel set length, ear length, and seed set length decreased as sowing date was delayed. The number and yield of marketable ears were the highest at 100%, in addition to soil testing-based recommended fertilization like in the first cropping. It has been found that securing yield by July 15^th to finish the second seeding of the crop in the central part of Korea is advantageous. These results of this study will be helpful to farmers for the double cropping of waxy corn cultivation and management.

• Korean Journal of Plant Resources
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• v.1 no.1
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• pp.1-7
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• 1988

This experiment were carried out to study the heritability, genotypic, pheno-typic and environmental correlation in four edible oil crops. Heritabilities of flowering date, maturing date, plant height and weight of 1, 000 grains in rape were high. A highly significant positive correlation was found between flowering date and maturing date, plant hight and ear length, number of pods per ear and flowering date, maturing date and plant hight, The number of seed per pod showed also significant positive correlation with flowering or maturing date as well as with the relationship between weight of 1, 000 grains and plant height or ear length inrapeseed, respectively. Heritabilities of maturing date, length of stem with eapsule and number of seed per capsule were high, in sesame. Genotypic correlation between plant height and length of stem with capsule, length of stem with capsule and number of capsule per plant, number of capsule per plant and weight of 1, 000 grains, weight of 1, 000 grains and yield were highy positive in sesame. Heritabilities of flowering date, length of main stem, weight of 100 grains and number of shells per square meter in peanut were high, There was positive genotypic correlation between length of main stem and yield, number of shells per quare meter and matured seed ratio, number of shells per square meter and yield, 100 grains weight and yield. On the other hand, a significant negative correlation appeared between flowering date and yield. Heritabilities of days to flowering, stem length, stem diameter and weight of 1, 000 grains in perila were high. There was positive genotypic correlation between stem length and stem diameter, number of pods per plant, stem weight etc, between number of internodes and number of pods per plant, stem weight, number of valid branches and number of pods plant as well, respectively. While, a significant negative correlation was observed between number of valid branches and weight of 1, 000 grains, between number of pods per plant and weight of 1, 000 grains.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.9
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• pp.1042-1050
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• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX(Korea Train eXpress) in tunnel. The severe pressure change in tunnel may give rise to the ear-discomfort for passenger and fatigue for car body. The external and internal pressure of rolling stock have been measured by using the running test with atmospheric pressure sensors and portable data acquisition system in high speed train. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. We found that there are similar patterns of external pressure change for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity. And, the patterns of pressure wave in tunnel are classified into eight groups.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1655-1660
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• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX(Korea Train eXpress) in tunnel. The external and internal pressure of rolling stock have been measured by using the atmospheric pressure sensors and portable data acquisition system on Seoul-Busan high speed railroad line. These pressure change may give rise to the ear-discomfort for passenger and fatigue for car body. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. From the results of experiment, the pattern of pressure change generally agrees to RTRI's experimental result for Shinkansen. We found that there are similar patterns of external pressure variation for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity.

• Journal of the Korean Society for Railway
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• v.7 no.3
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• pp.200-207
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• 2004

Theoretical study has been conducted to clarify pressure characteristics of KTX (Korea Train eXpress) in tunnel. The severe pressure change in tunnel may give rise to the ear-discomfort for passenger and fatigue for car body. Critical tunnel lengths which are induced by x-t diagram analysis can be applied to the experimental results measured by using the running test with atmospheric pressure sensors and portable data acquisition system in previous study. In this study, the tunnels from 200m to 4000m in length have been chosen for the investigation of tunnel length effects. We found that there are similar patterns of external pressure change for each critical tunnel length. The critical tunnel lengths are governed by train speed, train length and sonic velocity. And, the patterns of pressure wave in tunnel are classified into eight groups.