• Journal of Animal Science and Technology
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• v.52 no.5
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• pp.441-448
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• 2010

This study was carried out to investigate the effects of the seeding dates and growth periods on the growth characteristics, dry matter yield and feed value of corn for silage in paddy field. The experimental design was arranged in a randomized block design with three replications. Treatments consisted of five seeding dates, 1 May (T1), 8 May (T2), 15 May (T3), 22 May (T4) and 29 May (T5). And harvesting time homologized by August 24. Therefore, growing periods were 115 days (T1), 108 days (T2), 101 days (T3), 94 days (T4) and 87 days (T5), respectively. In maturities at harvest time, T1, T2, T3, T4 and T5 were full dent, early dent, late dough, dough and early dough stage, respectively. Plant height and numbers of root system were highest in T5 (p<0.01), but leaf length was higher in T4 than others (p<0.05). Dead leaf, tip filling degree and ear circle were higher in T1 than others (p<0.05, 0.01). Leaf width, ear height, leaf number, ear length, stem diameter, stem hardness and brix were not significantly different among the treatments. Dry matter yield and TDN yield were higher in the order of T1 > T2 > T3 > T4 > T5 (p<0.01). Crude protein, crude ash, NDF, ADF and crude fiber were significantly higher in T4 (p<0.05, 0.01). But crude fat was the highest in T1, T3 was the lowest as compared to other treatments (p<0.01). Total EAA(essential amino acids) were higher in order of T4 > T3 > T1 > T2 > T5, and total NEAA (nonessential amino acids) were higher in order of T1 > T4 > T2 > T3 > T5, and total amino acids were higher in order of T4 > T1 > T3 > T2 > T5. But no significant differences were found among the treatments. TUFA (total unsaturated fatty acid) and TSFA (total saturated fatty acid) were in order of T1 > T2 > T3 > T5 > T4 (p<0.01). Minerals were the highest in T4 (4,721.25 mg/kg), and T2 (2,970.80 mg/kg) was the lowest as compared to other treatments (p<0.05). Based on the above results, seeding dates could be recommended as early May, and harvest times is yellow ripe stage for qualitative and quantitative production of corn for silage in rice paddy field soil.

• Journal of Korea Soil Environment Society
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• v.3 no.2
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• pp.13-29
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• 1998

Recently, It is increasing popularity to research on the soil remediation in aspect of management by reason of the hazardous impact on the contaminated soil in Korea. It was investigated high levels of arsenic salts in soil near abandoned five mines(Darak, Daduk, Jingok, Dalsung, Ilkwang) located in Youngnam area. Arsenic, classified as group A(Human Carcinogens) from IRIS, have shown statistically significant increment in skin cancer with oral exposure. This paper was conducted to predict excess cancer risk value (to the skin cancer) based on multiple pathway such as soil ingestion, dermal uptake and food(plant) ingestion contaminated by arsenic, and also, to identify the remedial goal regarded in future land use. The mine having the highest arsenic level was Daduk(mean : 1950mg/kg) and the next rank was Jingok(1690mg/kg), Ilkwang(352.37mg/kg), Dalsung(86.08mg/kg), Darak(0.83mg/kg). The chronic daily intake to the multiple exposure were calculated using Monte-Carlo simulation regarded in future land use and used q: value was $1.5(mg/kg/day)^{-1}$ to the oral proposed by IRIS(1997). The computated excess cancer risk 95th value to all the mine regarding future land use as residential and rural area were more than $10^{-4}$. If the level of acceptable risk is aimed for 1$\times$$10^{-6}$, it could be used Darak as commercial and industrial area without soil remediation due to the lowest risk value(6$\times$$10^{-8}$ and 3$\times$$10^{-8}$). Computated remedial goal based on 1$\times$$10^{-6}$ of acceptable risk to the future land use as the residential, rural, commercial and industrial area were 0.02mg/kg, 0.003mg/kg, 97.31mg/kg and 194.62mg/kg, respectively.

• Horticultural Science & Technology
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• v.18 no.3
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• pp.334-341
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• 2000

To develop a nutrient solution for a closed hydroponic system in potato (Solanum tuberosum L.) 'Atlantic' and 'Superior' potatoes were grown with the nutrient solutions whose strengths were 0.25, 0.5, 1.0, and 1.5 of the concentration of the nutrient solution developed by the National Horticultural Experiment Station in Japan. The best results in potato growth and yield were obtained with 0.5 and 1.0 strength nutrient solutions, and nutrient compositions for potato were determined based on the 1.0 strength nutrient solution; $14.4me{\cdot}L^{-1}\;N,\;4.2me{\cdot}L^{-1}\;P,\;7.5me{\cdot}L^{-1}\;K,\;5.5me{\cdot}L^{-1}\;Ca$, and $3.5me{\cdot}L^{-1}\;Mg$ for stolon growth stage and $14.8me{\cdot}L^{-1}\;N,\;4.0me{\cdot}L^{-1}\;P,\;8.5me{\cdot}L^{-1}\;K,\;6.5me{\cdot}L^{-1}\;Ca$, and $3.0me{\cdot}L^{-1}\;Mg$ for tuber growth stage. To examine the suitability of the nutrient solutions developed for potato, the strengths of 1.0 (PS 1.0S), 0.75 (PS 0.75S), or 0.5 (PS 0.5S) were compared with half-strength of Japanese Horticultural Experiment Station' solution (JH 0.5S). Changes in pH, EC, and mineral concentrations in nutrient solutions depended more on solution strength and growth stage than on the type of nutrient solution. However, most elements in solution remained constant with plant age in PS 0.75S solution during stolon growth stage, and in PS 0.5S solution during tuber growth stage. The greatest growth and tuber yield was obtained in the standard strength solution (PS 1.0S), and potato solution developed in this experiment was recommended for hydroponic culture of potato in a closed system.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.864-871
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• 2014

Seed viability is affected by storage conditions and rapid loss of viability in storage is the major cause for low germination. This study was carried out to examine the effect of packaging materials and storage temperature on seed germination rate over 10 years in two species (Capsicum annuum L. and Brassica rapa L. ssp. pekinensis) and determine effective storage conditions for maintaining seed viability. Seeds were packaged in aluminum poly pouches under vacuum, polyethylene bottles, and paper bags containing silica gel and stored under one of two controlled conditions ($15^{\circ}C$, RH 40% or $5^{\circ}C$, RH 30%) or at ambient condition. Seed germination was recorded at 6-month intervals for 10 years. The seeds of both species showed no decline in viability until 6.5 years at 15 or $5^{\circ}C$, irrespective of packaging materials. However, under ambient conditions, the seeds of chili pepper and Chinese cabbage in paper bags lost viability after 4 and 5 years, respectively. By contrast, seeds of both species in vacuum-aluminum poly pouches exhibited a 99% germination rate after 6 years under ambient conditions. Pepper seeds in the vacuum-aluminum poly pouches maintained a 93% germination rate after 10 years in ambient conditions. These results indicated that a special seed storage facility for maintaining viability of chili pepper and Chinese cabbage seed might not be essential and seed testing would not be necessary for 10 years, if chili pepper and Chinese cabbage seeds were packed in ambient/vacuum-aluminum poly pouches or $5^{\circ}C$/vacuum-aluminum poly pouches.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.803-811
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• 2014

This study was carried out to investigate the effect of relative humidity (70, 80, 90, and 95%) and to examine the interrelationship of temperature (15, 20, and $25^{\circ}C$) and relative humidity (60, 70, 80, and 90%) in the greenhouse on growth and occurrence of white rust in chrysanthemum 'Baekma'. The developmental stages of white rust were monitored from the initial occurrence to sporidium formation in teliospores. When the relative humidity of greenhouse was adjusted to 90% or more for 40 days, the occurrence rate of white rust, the number of infected leaves, and the number of symptoms per leaf were more than 97%, 10, and 55, respectively. However, in the treatment with 70% relative humidity, the occurrence rate of white rust dropped to 30% and only two spots of symptoms were observed with only 1 or 2 infected leaves per plant. The growth of cut flowers, such as fresh weight and leaf number, was the highest in 70% relative humidity. In the 90% relative humidity treatment, the first symptom of white spot appeared at 6 days after planting in chrysanthemum infected with white rust (stage 1), and then after one day, teliospores came out through the epidermal tissue of leaf (stage 2). The telium was formed with increasing teliospores after 1 to 2 days (stage 3), and then the promycelia developed from teliospores (stage 4). After a lapse of 4 to 5 days, sporidia formed on promycelia (stage 5). Regardless of relative humidity, white rust did not occur at all in treatments at $25^{\circ}C$. In treatments at $20^{\circ}C$, the number of sporidia was high regardless of relative humidity, but white rust did not occur in 60% and 70% relative humidity. As the relative humidity was higher, the number of sporidia and occurrence rate of white rust greatly increased, but the occurrence rate of white rust decreased to less than 14% in 60% and 70% relative humidity in treatment at $15^{\circ}C$.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.772-781
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• 2013

The objective of this study was to develop simple sequence repeat (SSR) markers from expressed sequence tags (EST) of lettuce (Lactuca sativa) and identify 9 germplasms from 3 wild species of lettuce and 61 commercial cultivars using the developed EST-SSR markers. A total of 81,330 lettuce ESTs from NCBI databases were used to search for SSR and 4,229 SSR loci were identified. The highest proportion (59.12%, 2500) was represented by trinucleotide, followed by dinucleotide (29.70%, 1256) and hexanucleotide (6.62%, 280) among SSR repeat motifs. Totally 474 EST-SSR primers were developed from EST and a random set of 267 primers was used to assess the genetic diversity among 9 germplasms and 61 cultivars. Out of 267 primers, 47 EST-SSR markers showed polymorphism between 7 cultivars. Twenty-six EST-SSR markers among 47 EST-SSR markers showed high polymorphism, reproducibility, and band clearance. The relationship between 26 markers genotypes and 70 accessions was analyzed. Totally 127 polymorphic amplified fragments were obtained by 26 EST-SSR markers and two to nine SSR alleles were detected for each locus with an average of 4.88 alleles per locus. Average polymorphism information content was 0.542, ranging from 0.269 to 0.768. Genetic distance of clusters ranged from 0.05 to 0.94 between 70 accessions and dendrogram at a similarity of 0.34 gave 7 main clusters. Analysis of genetic diversity revealed by these 26 EST-SSR markers showed that the 9 germplasms and 61 commercial cultivars were discriminated by marker genotypes. These newly developed EST-SSR markers will be useful for cultivar identification and distinctness, uniformity and stability test of lettuce.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.344-360
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• 2017

Zoysiagrasses are important turf plants used for school playgrounds, parks, golf courses, and sports fields. The two most popular zoysiagrass species are Zoysia japonica and Zoysia sinica. These are widely distributed across different growing zones and are morphologically distinguishable from each other; however, it is phenotypically difficult to differentiate those that grow along the coastal line from those in beach area habitats. A combination of morphological and molecular approaches is desirable to efficiently identify these two plant cultivars. In this study, we used a rapid identification system based on DNA barcoding of the nrDNA-internal transcribed spacer (ITS) regions. The nrDNA-ITS regions of ITS1, 5.8S nrDNA, and ITS2 from Z. japonica, Z. sinica, Agrostis stolonifera, and Poa pratensis were DNA barcoded to classify these grasses according to their molecular identities. The nrDNA-ITS sequences of these species were found at 686 bp, 687 bp, 683 bp, and 681 bp, respectively. The size of ITS1 ranged from 248 to 249 bp, while ITS2 ranged from 270 to 274 bp. The 5.8S coding region ranged from 163 - 164bp. Between Z. japonica and Z. sinica, nineteen (2.8%) nucleotide sites were variable, and the G+C content of the ITS region ranged from 55.4 to 63.3%. Substitutions and insert/deletion (indel) sites in the nrDNA-ITS sequence of Z. japonica and Z. sinica were converted to cleaved amplified polymorphic sequence (CAPS) markers, and applied to the Zoysia grasses sampled to verify the presence of these markers. Among the 62 control and collected grass samples, we classified three groups: 36 Z. japonica, 22 Z. sinica, and 4 Z. japonica/Z. sinica hybrids. Morphological classification revealed only two groups; Z. japonica and Z. sinica. Our results suggest that used of the nrDNA-ITS barcode region and CAPS markers can be used to distinguish between Z. japonica and Z. sinica at the species level.

• Journal of Life Science
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• v.25 no.12
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• pp.1408-1414
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• 2015

In this study, to retain a stable bacterial inoculant, Bacillus strains showing antifungal activity were screened. The improved production, antifungal mechanism, and stability of the antifungal metabolite by a selected strain, AF4, a potent antagonist against phytopathogenic Botrytis cinerea, were also investigated. The AF4 strain was isolated from rhizospheric soil of hot pepper and identified as Bacillus subtilis by phenotypic characters and 16S rRNA gene analysis. Strain AF4 did not produce antifungal activity in the absence of a nitrogen source and produced antifungal activity at a broad range of temperatures (25-40℃) and pH (7-10). Optimal carbon and nitrogen sources for the production of antifungal activity were glycerol and casein, respectively. Under improved conditions, the maximum antifungal activity was 140±3 AU/ml, which was higher than in the basal medium. Photomicrographs of strain AF4-treated B. cinerea showed morphological abnormalities of fungal mycelia, demonstrating the role of the antifungal metabolite. The B. subtilis AF4 culture exhibited broad antifungal activity against several phytopathogenic fungi. The antifungal activity was heat-, pH-, solvent-, and protease-stable, indicating its nonproteinous nature. These results suggest that B. subtilis AF4 is a potential candidate for the control of phytopathogenic fungi-derived plant diseases.

• Journal of Life Science
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• v.23 no.8
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• pp.1025-1031
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• 2013

From a 95% ethanolic extract of H. diffusa, four marker compounds (HD1~HD4) were isolated, which were relatively unique and exist in comparably high contents. The structures of marker compounds were identified as digitolutein (1), 2-hydroxy-3-methylanthraquinone (2), (E/Z)-6-O-p-coumaroyl scandoside methyl ester (4:1 mixture) (3), and (E/Z)-6-O-p-methoxycinnamoyl scandoside methyl ester (4:1 mixture) (4), respectively, on the basis of $^{13}C$ and $^1H$-NMR analyses. The calibration curves of marker compounds showed high linearity, as their correlation coefficient ($R^2$) were in the range of 0.9991~0.9999. In addition, the limit of detection (LOD) and the limit of quantification (LOQ) were $0.03{\sim}0.07{\mu}g/ml$ and $0.099{\sim}0.231{\mu}g/ml$, respectively. The intra-day/inter-day precision and accuracy were 0.23~2.00%/0.25~1.16% and 94.60~108.44%/94.73-110.23%, respectively. The optimal HPLC conditions for the simultaneous quantification of HD1~HD4 were as follows: stationary phase; Merck Chromolith RP-18e ($100{\times}4.6mm$, $5{\mu}m$), column temp.; room temperature, UV detection at 280 nm, flow rate; 2.0 ml/min, injection volume; $10{\mu}l$, mobile phase; start with the mixture of 80% solvent A ($H_2O$ containing 0.5% acetic acid) and 20% solvent B (methanol containing 0.5% acetic acid) and gradually decrease solvent A to 40% in 9 min., then retain this condition to 18 min. Under the HPLC condition, the four marker compounds 1~4 were successfully separated without any interference of other constituents. The results obtained in this study are expected to be helpful for the development of nutraceutics and natural medicines and for the quality control of this plant.

• Journal of Life Science
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• v.30 no.4
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• pp.359-369
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• 2020

Although many studies on immune modulatory materials have used RAW 264.7 cells, few have used T cell-derived TK-1 cell lines. Moreover, although some studies have investigated the efficacy of plant-derived β-sitosterol, few have examined the immunomodulatory activity of its analogue, daucosterol. In this study, β-sitosterol and daucosterol were isolated from D. batatas and identified by nuclear magnetic resonance spectroscopy. To evaluate the immune-enhancing or inhibitory effects of the isolated phytosterols, the expression levels of the inflammatory response genes COX-2, TNF-α, IL-6, and iNOS were analyzed by RT-PCR. The relative expression levels of TNF-α and iNOS in RAW 264.7 cells were increased more than threefold with β-sitosterol treatment comparing to those of untreated control. In the case of TK-1 cells, the expression level of TNF-α was decreased and the expression level of iNOS was increased in a β-sitosterol concentration-dependent manner. The expression levels of COX-2, TNF-α, and IL-6 increased by approximately 0.7-1.2 times in RAW 264.7 cells treated with daucosterol compared to those of untreated control, but iNOS expression decreased by 0.8-0.18 times. In the case of daucosterol-treated TK-1 cells, the expression levels of TNF-α, IL-6, and iNOS were markedly reduced from those of TK-1 cells treated only with lipopolysaccaride. As a conclusion, β-sitosterol treatment increased TNF-α and iNOS expression levels in RAW 264.7 cells, thus exerting an immune- boosting effect. However, in TK-1 cells, iNOS expression increased while TNF-α expression decreased, indicating an immunosuppressive activity of β-sitosterol. Daucosterol appears to exert an immunosuppressive effect in both macrophages and T cell lines by inhibiting iNOS expression in RAW 264.7 cells and greatly inhibiting the expression of TNF-α, IL-6, and iNOS in TK-1 cells.