• Korean Journal of Plant Resources
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• v.29 no.4
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• pp.479-494
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• 2016

The aim of this study is to select the superior resources of high yield, high content of functional material optimal to mechanical harvesting by the evaluation of crop growth and yield characteristics in sorghum germplasm. One hundred accessions of sorghum germplasm were used in this experiment. Days from seeding to heading date showed the range from 68 to 94 days with the highest frequency proportion was the group from 80 to 85 days, which occupied 34% (34 plant resources) of 100 germplasm. Ear types of 100 sorghum germplasm could be classified as 7 types of broom-tillering, half broom-tillering, extreme open-loose type, open-loose type, intermediate type, compact type, extreme-compact type of which intermediate type was the highest ratio of 28% (28 plant resources) of 100 germplasm. Yield showed the range from 106 to 365 ㎏/10a with the highest frequency proportion of it was the group from 150 to 200 ㎏/10a, which occupied 44% (44 plant resources) of 100 germplasm. Among 100 sorghum germplasm, 18 ideal resources of high yield and short plant height appropriate for mechanical harvesting were selected. In order to evaluate high content of functional substance, selected 18 resources were analyzed for total polyphenol content, DPPH radical scavenging activity and total anthocyanin content. Finally, we selected 5 resources of short plant height, high yield, high content of total polyphenol and high DPPH radical scavenging activity among 18 genetic resources.

• Journal of The Korean Society of Grassland and Forage Science
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• v.36 no.4
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• pp.318-324
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• 2016

In order to study the effect of barley, Italian ryegrass (IRG), and legume mixture on nitrogen fixation and transfer to grasses on spring paddy field, an experiment was carried out from Oct. 2006 to June 2007 in Naju, Korea. A split plot design with three replications was used for the experiment. One reference plot was assigned for each treatment to determine nitrogen fixation. Main plots consisted of Chinese milk vetch, crimson clover, forage pea, and hairy vetch with barley, respectively. Subplot treatment were barley or IRG with four seeding ratio of legumes (50:50, 60:40, 70:30, and 80:20). To estimate N fixation by legumes, $^{15}N$ isotope dilution technique was used. $^{15}N$ fertilizer [$(^{15}NH_4)_2SO_4$ solution at 99.8 atom N] was uniformly applied to $600cm^2$ in the middle of each plot on April 15, 2007. Plots were harvest by hand on June 8, 2007. Dried sample were ground to a fine power and analyzed for total N isotope N. $^{15}N$ was determined using elemental analyzer-isotope ratio mass spectrometry. The calculation of N transfer was determined with the isotope dilution method. The content of N was higher in legumes than that in barley or Italian ryegrass. Nitrogen level in forage pea was significantly higher than that of other legumes. There were significantly differences in N content between legumes in IRG mixture. Atom % $^{15}N$ excess was significantly different in legumes with barley. The 60:40 sub plot had higher (p<0.05) atom % $^{15}N$ than other seeding ratio treatments. The enrichment ranged from 0 to 0.58. Compared to barley, the enrichment of IRG with its accompanied legumes was higher, ranging from 0.38 to 1.0. The N derived from the atmosphere (Ndfa) ranged from 0% to 49.5% with barley-legume mixture. It ranged from 0 to 60.5% in IRG-legume plots. N transfer from legumes to neighboring grasses was 12.3 to 90.9 kg/ha for barley-legume mixture and 31.7 to 107.8 kg/ha for IRG plots. IRG plots showed higher N transfer for IRG-legume mixture in general based on difference method. Based on $^{15}N$ dilution method, the N transfer was 0 to 36.1 kg/ha for barley-legume mixture and 0 to 50.6 kg/ha for IRG plots. There was a tendency toward higher N transfer on the difference method than that of the $^{15}N$ dilution method.

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.201-210
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• 2017

BACKGROUND: The current study was to monitor of 9 veterinary antibiotics (ceftiofur, clopidol, florfenicol, sulfamethazine, sulfamethoxazole, sulfathiazole, tetracycline, tiamulin, and tylosin) in manure using liquid chromatography-tandem mass spectrometry (LC-MS/MS) in positive and negative electrospray ionization mode. METHODS AND RESULTS: Sample preparation was carried out using Mcllvaine buffer and citrate salts to adjust the pH of the sample followed by purification with dispersive solid phase extraction (d-SPE). Separation of analytes during LC-MS/MS analysis was conducted using an Eclipse Plus $C_{18}$ column and the mobile phase was in gradient mode with, 0.1% formic acid and 5 mM ammonium formate in methanol (A) and 0.1% formic acid and 5 mM ammonium formate in distilled water (B). The linearity of the matrix-matched calibrations of all tested antibiotics was good, with $R^2$ determination coefficients ${\geq}0.9920$. The limit of detection (LOD) and quantifications (LOQ) were $0.1-67.0{\mu}g/kg$ and $0.4-200.0{\mu}g/kg$, respectively. Analysis of 13 solid and liquid manure samples taken from the Republic of Korea revealed concentrations less than $0.7{\mu}g/kg$ for tiamulin, $1497.6{\mu}g/kg$ for sulfamethazine. CONCLUSION: To monitor 9 veterinary antibiotics from manure samples in 13 provincial areas throughout the Republic of Korea, an analytical method was developed. The developed method was fully validated and successfully applied for monitoring various veterinary antibiotics in manure samples.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.8
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• pp.971-978
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• 2017

Danggui leaf (Angelica acutiloba Kitagawa) has numerous dietary fiber and healthy functional properties such as anti-inflammatory activity. However, it is usually discarded after its roots are harvested. For wide application of danggui leaf, squeezed danggui leaf juice was used for making pan bread. Treatments included imported wheat flour (IMWF) and domestic wheat flour (DOWF) as a control, 1% soluble solid contents of squeezed danggui leaf juice instead of wheat flour (1% SDLJ), 2% SDLJ, 3% SDLJ, and 4% SDLJ. In the fermentation expansion, dough volume was not significantly different between DOWF and 1% SDLJ, whereas it decreased according to increased amount of squeezed danggui leaf juice. Regarding physical properties, springiness and cohesiveness decreased according to increased amount of squeezed danggui leaf juice and longer storage period. Gumminess, brittleness, and hardness increased according to increased amount of squeezed danggui leaf juice, although these were not statistically different among IMWF, DOWF, and 1% SDLJ after making pan bread. Principal component analysis (PCA) was performed to assess the correlation between storage period and physical properties. In the PCA, variance proportion of principal component (PC) 1 was 0.87 while that of PC 2 was 0.10. Further, 1% SDLJ showed similar results as DOWF and INWF after making pan bread and after 3 days of storage. In conclusion, use of 1% SDLJ is desirable for making squeezed danggui leaf juice.

• Korean Journal of Poultry Science
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• v.42 no.1
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• pp.77-86
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• 2015

Chicken is one of the major livestock, especially for supplying proteins to human. The chicken genome size is approximately one-third compared with that of the human genome and regarded as a valuable model animal for genetics and development biology. In this study, we constructed the genetic linkage map for Korean native chicken (KNC) using 131 microsatellite (MS) and 8 single nucleotide polymorphism (SNP) markers. As a result, the total map length was calculated as 2729.4 cM and the average genetic distance between markers was 19.64 cM. The marker orders and genetic distances were well matched with the consensus linkage map except for the physical order of ADL0278 and MCW0351 in GGA8. In addition, the recombination rates in marcrochromosomes were 3.7 times higher than that of microchromosomes. The average numbers of alleles, expected heterozygosity (Hexp) and polymorphic information content (PIC) values were calculated as 5.5, 0.63 and 0.58, respectively. These results will give useful information for the understanding of genetic structure and QTL studies in KNC.

• Korean Journal of Soil Science and Fertilizer
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• v.27 no.2
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• pp.65-71
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• 1994

This study was conducted to investigate the influence of treatment of fly ash on heavy metal contents in the arable soils. Rice was cultivated on the two types of paddy field(clay loam and sandy loam soil) with 0, 4, 8, 12t/10a of anthracite fly ash and bituminous coal fly ash, respectively. And soybean was cultivated on the same types of upland field with those of 0, 3, 6, 9t/10a, respectively. At the harvest time, the heavy metal contents in surface and subsoil were investigated. The results were summarized as follows : 1. Anthracite fly ash. 1) In the paddy field of clay loam, the contents of Cu and Zn in the surface soil and Cd and Ni in the subsoil were increased with the increase of the amount of fly ash applied, but the others didn't show that tendency. 2) In the paddy field of sandy loam, only the content of Fe was increased in the surface and subsoils. 3) In the case of upland soil, the concentration of Ni and Cr in the surface soil and Cd in the subsoil were increased in the clay loam soil, and those of Cr in the surface soil and Pb in the subsoil were increased in the sandy loam soil. 2. Bituminous coal fly ash 1) In the paddy field of clay loam, the contents of Cu and Zn in the subsoil were increased with increase of the amount of fly ash applied, but in the case of sandy loam, those of Pb and Ni in the surface soil were increased. 2) In the upland soil of clay loam, the concentration of Ni in the surface soil and Pb in the subsoil were increased. 3) In case of upland soil of sandy loam, the contents of Cr and Fe were increased in the surface and subsoil, respectively, but those of Cu and Mn were increased in the both of the surface and subsoil.

• Journal of Food Hygiene and Safety
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• v.33 no.4
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• pp.310-315
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• 2018

Under the "Positive List System (PLS)," a uniform limit of 0.01 mg/kg is applied if the agricultural product does not have a Maximum Residue Limit (MRL) for a pesticide. The purpose of this research is to conduct residual pesticide monitoring on tropical fruits distributed in Gyeonggi-do to investigate the effects of PLS and provide basic materials for establishing MRLs of residual pesticides for tropical fruits produced in Korea. By inspecting 120 tropical fruits distributed in Gyeonggi-do according to Multi-class pesticide multi-residue methods, we detected sevenfruits from threekinds of banana, mangoes, and kiwis with six different residual pesticides. Azoxystrobin and chlorpyrifos were detected from bananas, chlorfenapyr from mangoes, and chlorothalonil, iprodione, and procymidone from kiwis. A single case of chlorfenapyr and chlorothalonil was found with a mango and a kiwi produced in Korea, respectively, and by applying PLS we found that they exceeded the MRL of residual pesticide. Thus, it is necessary to set the MRL of residual pesticides for tropical fruits produced in Korea.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.309-315
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• 2009

Maintenance of adequate soil water content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil water movement for precision irrigation would allow efficient supply of water to crops, thereby resulting in minimization of water drainage and contamination of ground water. This research reports on the characterization of spatial and temporal variations in water contents through three different textured soils, such as loam, sandy loam, and loamy sand, when water is applied on the soil surface using an one-line drip irrigation system and the soils are dried after the irrigation stops, respectively. Water contents through each soil profile were continuously monitored using three Sentek probes, each consisting of three capacitance sensors at 10, 20, and 30cm depths. Spatial variability in water content for each soil type was strongly influenced by soil textural class. There were big differences in wetting pattern and the rate of downward movement between loam and sandy loam soils, showing that the loam soil had a wider wetting pattern and a slower rate of downward movement than did the sandy loam soil. The wetting pattern in loamy sand soil was not apparent due to a low variability in water content (< 10%) by a lower-water holding capacity as compared to those measured in the loam and sandy loam soils, implying that the rate of water drainage below a depth of 30cm was high. When soils were dried, there were highly exponential relationships between water content and time elapsed after irrigation stops ($r^2$${\geq}$0.98). It was estimated that equilibrium moisture contents for loam, sandy loam, and loamy sand soils would be 17.6%, 6.2%, and 4.2%, respectively.

• Journal of Bio-Environment Control
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• v.18 no.4
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• pp.431-435
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• 2009

This study was conducted to compare the effect of various LED and UVa light to enhanced coloration of paprika fruits cultivars; 'Special', 'Helsinki'. Immatured paprika fruits were irradiated with red LED, blue LED and UVa lights which were high intensity (red: $50{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $70{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $3{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$) and low intensity (red: $20{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, blue: $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, UVa: $0.25{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The coloration of 'Special' cultivar was increased the fastest in high intensity UVa light for 2 days after treatment. There were no significantly difference among treatments except the low intensity UVa light. The coloration of 'Helsinki' was increased the fastest in blue LED light, and followed by red LED light and UVa light for 2 days after treatment. The $a^*/b^*$ value of 'Special' and $b^*$ value of 'Helsinki' that indicated the paprika fruit coloration were generally higher high intensity LED and UVa lights than low intensity LED and UVa lights. We couldn't find out any significantly different coloration effect among all treatments in final days of coloration. and rather than UVa treatment fruit shrunk the surface of paprika fruits.

• Journal of Food Hygiene and Safety
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• v.24 no.3
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• pp.232-237
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• 2009

This study was conducted to develop a model for describing the effect of storage temperature (4, 10, 15, 20, 25, 30 and $35^{\circ}C$) on the growth of Escherichia coli O157 : H7 in ready-to-eat (RTE) lettuce treated with or without (control) alkaline electrolyzed water (AIEW). The growth curves were well fitted with the Gompertz equation, which was used to determine the specific growth rate (SGR) and lag time (LT) of E. coli O157 : H7 ($R^2$ = 0.994). Results showed that the obtained SGR and LT were dependent on the storage temperature. The growth rate increased with increasing temperature from 4 to $35^{\circ}C$. The square root models were used to evaluate the effect of storage temperature on the growth of E. coli O157 : H7 in lettuce samples treated without or with AIEW. The coefficient of determination ($R^2$), adjusted determination coefficient ($R^2_{Adj}$), and mean square error (MSE) were employed to validate the established models. It showed that $R^2$ and $R^_{Adj}$ were close to 1 (> 0.93), and MSE calculated from models of untreated and treated lettuce were 0.031 and 0.025, respectively. The results demonstrated that the overall predictions of the growth of E. coli O157: H7 agreed with the observed data.