• KOREAN JOURNAL OF CROP SCIENCE
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• v.54 no.2
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• pp.172-180
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• 2009

This study was carried out to compare the physicochemical characteristics and sensory quality of Sogokju (Korean traditional rice wine) prepared with waxy rice varieties. Among tested waxy rice varieties, highest protein contents (8.11%) was observed in cv. Sangjuchal, and highest whiteness and L-value were observed in cv. Hwaseonchal, while no significant differences in gelatinization temperature could be observed among tested varieties, and cv. Boseokchal and Sinseonchal exhibited higher breakdown viscosity compared to the others. The alcohol contents of Sogokju with waxy rice varieties ranges from 13.0 to 13.4%, and the brix degree and turbidity were within the range of 20.5 to 24.6 $^{\circ}Bx$, and 0.0344 to 0.0530, respectively. The highest L-value (6.90), b-value (l.45), pH (4.79), total acidity (0.8384%), and glucose content (10.843 g/100 ml) could be observed in Sogokju made with cv. Sangjuchal. The organic acids such as succinic acid, malic acid, citric acid and oxalic acid could be detected in Sogokju. Although no variety-dependant differences in appearance, aroma, and taste could be found in sensory evaluation, Sogokju made with cvs. Sinseonchal, Haepyeongchal, and Hwaseonchal showed higher overall quality than Sogokju made with cv. Dongjinchal, which is most widely used for Sogokju used for Sogokju production nowadays.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.166-176
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• 2015

Research was initiated to investigate root growth characteristics of major cool-season grasses (CSG) and to collect basic information useful for sports turf design, construction and maintenance. Several turfgrasses were evaluated in the USGA (United States Golf Association) soil system. Turfgrass entries were comprised 3 blends and 3 mixtures of Kentucky bluegrass (KB, Poa pratensis L.), perennial ryegrass (PR, Lolium perenne L.), and tall fescue (TF, Festuca arundinacea Schreb.). Significant differences were found in root growth, rooting potential and rooting development. These characteristics increased with time after seeding, but varied with establishment stages. In early stage, root length was highest with PR, intermediate with TF and lowest with KB. Evaluation in a middle stage indicated that root growth was similar to early-stage evaluation, but decreased by 13 to 31% compared with early-stage values. Root growth of late stage increased by 34 to 85% over middle-stage root growth. Overall, thhere was not much difference in root length among treatments, with all except Mixture I reaching 22cm in root length. Rooting potential ranking was variable with establishment stage, being PR > KB > TF in early stage, PR > TF > KB in middle stage and TF > PR > KB in late stage. At the end of the study, TF was rated best for rooting development, followed by PR and finally KB. Our results showed that TF was the best species in regard to overall rooting characteristics. TF exhibited excellent rooting development with time after establishment. Bunch-type PR showed fast root growth in the early stage, but rooting quality characteristics decreased with time, especially for rooting development. By contrast, rhizomatous-type KB was poor in early-stage root growth, but rooting characteristics improved with time after establishment. These variations in rooting characteristics among CSGs were considered to arise from differences in establishment vigor, growth habit and genetic characteristics. Information on root growth, rooting potential and rooting development by establishment stages will be useful for sports turf design, construction and maintenance.

• Korean Journal of Ecology and Environment
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• v.40 no.2
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• pp.285-293
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• 2007

The study was to determine zonal characteristics of nutrients and chlorophyll and evaluate their trophic relations in Daechung Reservoir. For this study, we compared longterm water quality data among three zones along with trophic state using 1993 to 2002 dataset, obtained from the Ministry of Environment, Korea. Total phosphorous (TP), Secchi depth (SD) and chlorophyll (CHL) showed typical longitudinal declines from the riverine to lacustrine zone, but total nitrogen (TN) was not evident. Largest seasonal variations in TP and CHL occurred during the summer monsoon from July to August. In the reservoir, ambient TN averaged 1.67 mg $L^{-1}$ and ratios of TN : TP averaged 88.04, indicating that nitrogen is not likely limited but phosphorus limitation was evident. Trophic State Index (TSI), based on CHL, TP, and SD, varied depending on the zones and seasons. Mean TSI (TP) in the riverine zone was 62 during the monsoon, indicating a hypertrophic condition, whereas the mean was 40 in the lacustrine, indicating a nearly oligotrophic. Values of TSI (CHL) showed maximum in the transition zone during the monsoon. The deviation analysis of TSI showed that about 65% of TSI (CHL)-TSI (TP) and TSI (CHL)-TSI (SD) values were less than zero and the lowest values were -42, indicating an effect of inorganic turbidity on algal growth in the reservoir. Correlation analysis of CHL vs. SD shewed greater correlation coefficient (p<0.001, r=-0.47) in the transition than other two zones (p<0.001, $r{\leq}-0.40$). Correlation analysis of TP vs. CHL was greatest in the lacustrine and TP was minimum in the lacustrine zone, indicating a lowest yield of algal biomass in the lacustrine. Overall data suggests that zonal response of chlorophyll yield at a given nutrient unit is clearly differed among the longitudinal gradients, so the management strategy such as cross sectional modelling should be provided in each zone.

• Journal of Animal Science and Technology
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• v.51 no.3
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• pp.185-192
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• 2009

Fatty acid synthase (FASN) is a multi-functional enzyme with a central role in the synthesis of long-chain fatty acid and has been considered as a positional candidate gene for BTA 19 quantitative trait loci (QTL) affecting milk-fat content and fatty acid composition. In this study, we sequenced the FASN gene in several cattle breeds including Hanwoo and imported beef cattle, and identified novel DNA polymorphisms and their linkage relationship in Hanwoo. We found a significant frequency difference of the FASN (AF285607) g.17924 A$\rightarrow$G polymorphism between Hanwoo (70%) and other breeds and this polymorphism has been known for an association with fatty acid composition in Angus. Furthermore, by direct DNA sequencing in 18 unrelated Hanwoo, we identified 27 SNPs including nine novel variations in the FASN gene. Among 27 SNPs identified in the FASN gene, four SNPs were further genotyped in 100 Hanwoo and 96 imported beef cattle, and analyzed for haplotype construction and association with beef quality traits. We performed haplotype block and linkage disequilibrium studies using four selected SNPs. Two different haplotype blocks (block A: g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$ A; block B: g.13125 C$\rightarrow$T and g.17924 G$\rightarrow$A) were constructed and the block A in particular had a very high r2 (0.936), which indicated a nearly complete linkage disequilibrium existed between the g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$A polymorphisms. A total of four major haplotypes (frequency > 0.05) were identified with the four polymorphisms including TATG (0.36), CGCG (0.31), CGTA (0.19) and TACG (0.06). Statistical association analysis revealed that the g.10568 C$\rightarrow$T and g.11280 G$\rightarrow$A polymorphisms in the FASN were significantly associated with meat color (P=0.004) and texture (P=0.0114). The g.13125 C$\rightarrow$T and g.17924 G$\rightarrow$A polymorphisms in the FASN were also significantly associated with back-fat thickness and quantity index (P=0.0179 and 0.0495, respectively). Our findings suggested that the FASN gene polymorphisms may be used for determining the (unsaturated) fatty acid contents and carcass trait in the Hanwoo beef.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.7-14
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• 2014

Tyrosinase (TYR) gene is located on chromosome 1 in chicken and it is composed of five exons and four introns. TYR gene is described as a key enzyme in melanin biosynthesis. Most examples of complete albinism in chicken have been due to defects in the tyrosinase gene. The association of feather color and sequence polymorphism in the Tyrosinase (TYR) gene was investigated using Korean Native chicken H breed (H_PL), Korean Native chicken L/W breed(L/W_PL) and 'Woorimatdag' commercial chickens (Woorimatdag_CC). From L_PL and W_PL breed analyses, 4 synonymous SNPs (locus G33A, G116A, C217T and C247T) and 2 SNPs (G838A and G958A) were detected in 4th exon and 4th intron of TYR gene respectively. The genotype frequencies for 6 SNPs were compared between L_PL and W_PL and W_PL represented homozygous SNP types in all the analyzed SNP positions while L_PL displayed various SNP types.

• The Korean Journal of Mycology
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• v.25 no.1 s.80
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• pp.46-67
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• 1997

From 1985 to 1993, we collected 20 isolates throughout Kangwon and obtained 6 isolates from other sources. A. mellea formed rhizomorph actively, and some of A. osroyae were poor in the formation of rhizomorph and some without formation of rhizomorph. A. tabescens was active in the growth of aerial mycelium and poor in the development of rhizomorph. In A. gallica, the mycelium development among the isolates were variable greatly, and especially in isolate A8(KNU-250), the mycelial development was similar to that of A. osroyae, but A8(KNU-250) showed the feature of A. gallica to change medium into brown color. In PCR-RFLP analysis of the IGS region in rDNA, the homology between each isolate in the A. mellea and A. ostoyae showed 100% homology. A. tabescens showed $0.919{\sim}0.974$ homology, and A. gallica showed $0.619{\sim}1.000$ homology. A19 and A12 showed 100% homology as the same group, but compared with other subgroups they showed less than 10% homology as $0.051{\sim}0.108$ value. In RAPD analyses, the isolates of A. mellea showed high homology among themselves as $0.983{\sim}1.000$, and A. ostoyae also showed high similarity. The homology between isolates of A. tabescens showed $0.594{\sim}0.953$ value because A. gallica showed $0.280{\sim}0.733$ value, and the variations between isolates were greater than other species. Especially, A19 and A22 were identified as new novel group which were remoted from other groups, and the homology between these two isolates showed 0.921 value, and the genetic similarity between these groups and other 4 groups showed less than 7% as $0.012{\sim}0.069$ value. Of 5 species identified in this study, 4 species were identified as A. mellea, A. ostoyae, A. tabescens, and A. gallica that were already reported ones and 1 species was suggested as a new specie in Korea.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.73-84
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• 2006

The objective of this study was to analyze long-term temporal trends of water chemistry and spatial heterogeneity for 10 sampling sites of the Yeongsan River watershed using water quality dataset during 1995 to 2004 (obtained from the Ministry of Environment, Korea). The water quality, based on multi-parameters of biological oxygen demand (BOD), chemical oxygen demand (COD), conductivity, dissolved oxygen (Do), total phosphorus (TP), total nitrogen (TN) and total suspended solids (TSS), largely varied depending on the sampling sites, seasons and years. Largest seasonal variabilities in most parameters occurred during the two months of July to August and these were closely associated with large spate of summmer monsoon rain. Conductivity, used as a key indicator for a ionic dilution during rainy season, and nutrients of TN and TP had an inverse function of precipitation (absolute r values> 0.32, P< 0.01, n= 119), whereas BOD and COD had no significant relations(P> 0.05, n= 119) with rainfall. Minimum values in conductivity, TN, and TP were observed during the summer monsoon, indicating an ionic and nutrient dilution of river water by the rainwater. In contrast, major inputs of total suspended solids (TSS) occurred during the period of summer monsoon. BOD values varied with seasons and the values was closely associated (r=0.592: P< 0.01) with COD, while variations of TN were had high correlations (r=0.529 : P< 0.01) with TP. Seasonal fluctuations of DO showed that maximum values were in the cold winter season and minimum values were in the summer seasons, indicating an inverse relation with water temperature. The spatial trend analyses of TP, TN, BOD, COD and TSS, except for conductivity, showed that the values were greater in the mid-river reach than in the headwater and down-river reaches. Conductivity was greater in the down-river sites than any other sites. Overall data of BOD, COD, and nutrients (TN, TP) showed that water quality was worst in the Site 4, compared to those of others sites. This was due to continuous effluents from the wastewater treatment plants within the urban area of Gwangju city. Based on the overall dataset, efficient water quality management is required in the urban area for better water quality.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.1
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• pp.38-44
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• 2005

In addition to the variation in nitrate accumulation of vegetables due to environmental conditions, there is also a distinct genetic variation. The variation of nitrate accumulation in some cultivars of lettuce and spinach commonly cultivated in Korea was investigated. Ten cultivars for both lettuce and spinach were grown in plastic containers filled with a 1:1 mixture of perlite and vermiculite with application of Hoagland No. 2 nutrient solution of high nitrate content (17.3 mM N) in a greenhouse condition. Plants were harvested four weeks after transplanting four-leaf stage seedlings. Plant growth was measured by fresh and dry matter of shoot, and contents of nitrate and other inorganic ions and organic solutes including sugar, amino acids and organic acids were measured. Large and significant genotypical variations in the nitrate content of the plants were found for both lettuce and spinach, and high negative correlations between nitrate content and fresh or dry weight were found in lettuce and spinach. Variation in nitrate accumulation of lettuce and spinach cultivars was not directly related to the differences in contents of organic and inorganic solutes, and this result indicates that photosynthesis and osmotic regulation are not directly related with the nitrate accumulation. Considering the correlations between nitrate content and plant growth of this study, it can be simply suggested that different cultivars of lettuce and spinach have their own inherited growth and physiological characteristics and also optimum nitrogen level required for the growth. Therefore when available nitrogen in root media is higher than the optimum level required for the inherited growth potential, some of the excess nitrate supplied can be accumulated in plants.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1120-1125
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• 2012

To assess fertilizer value of an quasi-aerobically fermented liquid clipped-grass fertilizer, aerobic incubation experiment using two texturally contrasting loam (L) and sandy loam (SL) soils was conducted for 60 days to investigate temporal variations in N mineralization pattern of the liquid fertilizer applied. To do so, the quasi-aerobically fermented liquid clipped-grass fertilizer was prepared, applied to each soil at a rate of 200 kg-N $ha^{-1}$ and aerobically $25^{\circ}C$ in the dark. During incubation, soil water content was adjusted to field moisture capacity (-33 kPa of soil matric potential) by adding distilled water as necessary to maintain their initial weights. At desired time of incubation (0, 1, 5, 10, 20, 40, and 60 days after incubation), soil was sampled and analyzed for inorganic nitrogen ($NH_4{^+}$-N and $NO_3{^-}$-N) concentrations, pH, EC, total carbon contents and total nitrogen contents. Concentrations of $NH_4{^+}$-N began to decrease right after incubation for L soils, and 10 days after incubation for SL soils, while those of $NO_3{^-}$-N began to increase onset of $NH_4{^+}$-N disappearance. The results of this study showed that quasi-aerobically fermented liquid clipped-grass fertilizer could serve as an alternative to chemical N fertilizer.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.260-267
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• 1998

This experiment used the enclosed bench-scale reactors of 242 liters was conducted to obtain basic data on temporal and spatial variations in temperature, oxygen and moisture content, which were important factors of biological activities, during composting of mixture of dairy manure and rice straw. The reactors with thermocouples, oxygen sensor and datalogger were aerated at four different rates of 0.09, 0.18, 0.90 and 1.79 l $min^{-1}kg$ dry $solids^{-1}$. The higher aeration rates were, the faster the rates of increase and decrease in composting temperature were in both of initial and turnover stage, and the smaller the temperature difference between exhaust air and composting materials. Composting temperature of initial stage increased suddenly in all aeration rates, then stationary phase of temperature in materials and exhaust air showed at $50{\sim}53^{\circ}C$ for 5 hours and at $45^{\circ}C$ between 5 and 15 hours, respectively. In initial stage the maximum temperature was decreased with increasing aeration rates but in the stage after turnover it was the opposite except for 1.79 l $min^{-1}kg^{-1}$. Time arrived at the maximum temperature of composting materials was later in low-aeration rates than high-aeration rates at both stages. Time maintained high-temperature more than $45^{\circ}C$ was rapidly decreased with increasing aeration rates. In initial stage of composting maintaining time of $65^{\circ}C$ or more was the longest in the treatments of 0.09 and 0.18 l $min^{-1}kg{-1}$, while those of $55{\sim}65^{\circ}C$ and $45{\sim}55^{\circ}C$ was in 0.90 and 1.79 l $min^{-1}kg{-1}$, respectively. The minimum oxygen content and the maximum oxygen consumption rate in exhaust air through composting materials showed the increased trends with increasing aeration rates. In initial stage the minimum oxygen content was ranged from 0.9% to 7.4% for 32 to 59.5 hours and the maximum oxygen consumption rate was $1.89{\sim}6.48$ $gh^{-1}kgVS^{-1}$. In the stage after turnover their levels were $2.1{\sim}19.9%$ and $1.76{\sim}3.49 %$g/h-㎏ VS, respectively, for 16 to 49.5 hours.