• The Plant Pathology Journal
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• 제21권2호
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• pp.158-163
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• 2005

Virus-induced gene silencing (VIGS) is a recently developed gene transcript suppression technique for characterizing the function of plant genes. However, efficient VIGS has only been studied in a few plant species. In order to extend the application of VIGS, we examined whether a VIGS vector based on TRV would produce recognizable phenotypes in soybean. Here, we report that VIGS using the Tobacco rattle virus (TRV) viral vector can be used in several soybean cultivars employing various agro-inoculation methods including leaf infiltration, spray inoculation, and agrodrench. cDNA fragments of the soybean phytoene desaturase(PDS) was inserted into TRV RNA-2 vector. By agrodrench, we successfully silenced the expression of PDS encoding gene in soybean. The silenced phenotype of PDS was invariably obvious 3 weeks after inoculation with the TRV-based vector. Real-time RT-PCR analyses showed that the endogenous level of GmPDS transcripts was dramatically reduced in the silenced leaf tissues. These observations confirm that the silenced phenotype is closely correlated with the pattern of tissue expression. The TRV-based VIGS using agrodrench can be applied to functional genomics in a soybean plants to study genes involved in a wide range of biological processes. To our knowledge, this is the first high frequency VIGS method in soybean plants.

• Journal of Microbiology and Biotechnology
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• 제19권10호
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• pp.1098-1102
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• 2009

Gamma-linolenic acid (GLA, C18:3 ${\Delta}^{6,9,12}$) is synthesized by a delta-6 fatty acid desaturase using linoleic acid (LA, C18:2 ${\Delta}^{9,12}$) as a substrate. To enable the production of GLA in the conventional yeast Pichia pastoris, we have isolated a cDNA encoding the delta-6 fatty acid desaturase from Cunninghamella echinulata MIAN6 and confirmed its function by heterogeneous expression in P. pastoris. Sequence analysis indicated that this cDNA sequence has an open reading frame of 1,404 bp, which encodes a 52 kDa peptide of 468 amino acids. This sequence has 64% identity to the previously reported delta-6 fatty acid desaturase from Rhizopus oryzae. The polypeptide has a cytochrome b5 domain at the N-terminus including the HPGG motif in the heme-binding region, as reported for other delta-6 fatty acid desaturases. In addition, this enzyme differs from other desaturases by the presence of three possible N-linked glycosylation sites. Analysis of the fatty acid composition demonstrated the accumulation of GLA to the level of 3.1% of the total fatty acids. Notably, the amounts of ginkgolic acid (C17:1) and palmitic acid (C16:0) were increased from 1.3% to 29.6% and from 15% to 33%, respectively. These results reveal that the modification of the fatty acid biosynthetic pathway by genetic manipulation in order to produce specific polyunsaturated fatty acids in P. pastoris is a promising technique.

• Asian-Australasian Journal of Animal Sciences
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• 제13권5호
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• pp.666-672
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• 2000

Two experiments were conducted to determine the ileal digestibility of the amino acids contained in sunflower meal using the regression technique and then applying the values obtained, in a growth trial, using growing-finishing pigs. For the digestibility trial, four 20 kg crossbred ($Yorkshire{\times}Landrace{\times}Beijing$ Black) barrows were fitted with simple Tcannula in the terminal ileum. After recovery, the barrows were fed one of four experimental diets according to a $4{\times}4$ Latin Square design. The pigs were fed corn-soybean meal based diets supplemented with 0, 25, 50 or 75% sunflower meal. For the growth trial, 80 crossbred ($Yorkshire{\times}Landrace{\times}Beijing$ Black) growing pigs (21.5 kg) were fed corn-soybean meal diets supplemented with 0, 5, 10 or 15% sunflower meal. Five pens (2 gilts and 2 castrates) were assigned to each treatment. With the exception of arginine and valine, the digestibility coefficients for the indispensible amino acids declined as the level of sunflower meal in the diet increased. During both the growing (21.5-49.1 kg) and finishing (49.1-90.3 kg) periods and over the entire experiment (21.5-90.3 kg), average daily gain declined in a linear manner (p<0.05) with increasing amounts of sunflower meal. Feed intake was not significantly altered while feed conversion declined in a linear manner (p<0.05) during the grower period only. When the entire experimental period was taken into account, there would appear to be little penalty in either growth or feed conversion for including sunflower meal at levels up to 10% of the diet. Therefore, the price relationship between sunflower meal and other high-protein feedstuffs may provide an excellant opportunity for pork producers to use sunflower meal in order to reduce feed costs.

• 농업과학연구
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• 제43권2호
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• pp.194-204
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• 2016

The pear psylla, Cacopsylla pyricola, is a very small sap-feeding insect of many commercial pear varieties that could be considered the most serious insect pest of pear. Detailed information on plant penetration activities of the pear psylla is essential to study its feeding behavior used to evaluate resistant traits to chemical control. The application of the electrical penetration graph technique (EPG) could provide a relevant insight into the nature of this resistance. EPG waveforms of C. pyricola were characterized on the basis of amplitude, frequency, voltage level, and electrical origin. Feeding behaviors of C. pyricola were recorded and analyzed by EPG analysis. During EPG monitoring, waveform PA occurred at the start of stylet penetration of pear leaf epidermal cell. Waveform PB followed, in which stylet secreted saliva was observed. Waveforms PC1 and PC2 involved penetrating and sucking behaviors in parenchyma cells and vascular parenchyma, respectively. In addition, waveform PC1 represented salivation into bundle sheath cells and ingestion from parenchyma. Otherwise, behaviors of salivation into phloem and ingestion from phloem produced waveforms PE1 and PE2, respectively. On the other hand, ingestion from xylem tissues showed waveform PG. Among the feeding patterns of C. pyricola described above, phloem feeding patterns occurred most frequently, followed by xylem feeding and parenchyma penetration patterns in descending order.

• 한국환경복원기술학회지
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• 제16권1호
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• pp.147-157
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• 2013

Rice is a main crop and rice field is the most important farmland in Korea. This study was conducted to propose the methodology assessing impact and vulnerability on rice production by climate change at the regional and national level in Korea. We evaluated a vulnerability of rice paddy according to the outbreak of a main disease and pest of a rice plant. As results, Jeju-do, Gyeongsangnam-do, and Jeollanam-do were more vulnerable area than others. In contrast, the southern central region including Gyeonggi-do was less vulnerable than others. The vulnerable index was significantly higher in 2050s (0.5589) than in present (0.3500). This result showed that the vulnerable to the disease and pest enlarge in the future. The adaptive capacity highly contributed to the vulnerability assessment index. The daily maximum temperature of June and the daily average temperature from May to August also contributed the climate exposure index. The area of occurring sheath blight, rice leaf blast and striped rice borer was related to the system sensitivity index. The ability of water supply (readjustment area of arable land per paddy field area) and rice production technique (rice yield per hectare) were the highly contributed variables to the adaption capacity index.

• ETRI Journal
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• 제44권4호
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• pp.573-587
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• 2022

The agricultural sector is completely different from other sectors since it completely relies on various natural and climatic factors. Climate changes have many effects, including lack of annual rainfall and pests, heat waves, changes in sea level, and global ozone/atmospheric CO₂ fluctuation, on land and agriculture in similar ways. Climate change also affects the environment. Based on these factors, farmers chose their crops to increase productivity in their fields. Many existing agricultural ontologies are either domain-specific or have been created with minimal vocabulary and no proper evaluation framework has been implemented. A new agricultural ontology focused on subdomains is designed to assist farmers using Jaccard relative extractor (JRE) and Naïve Bayes algorithm. The JRE is used to find the similarity between two sentences and words in the agricultural documents and the relationship between two terms is identified via the Naïve Bayes algorithm. In the proposed method, the preprocessing of data is carried out through natural language processing techniques and the tags whose dimensions are reduced are subjected to rule-based formal concept analysis and mapping. The subdomain ontologies of weather, pest, and soil are built separately, and the overall agricultural ontology are built around them. The gold standard for the lexical layer is used to evaluate the proposed technique, and its performance is analyzed by comparing it with different state-of-the-art systems. Precision, recall, F-measure, Matthews correlation coefficient, receiver operating characteristic curve area, and precision-recall curve area are the performance metrics used to analyze the performance. The proposed methodology gives a precision score of 94.40% when compared with the decision tree(83.94%) and K-nearest neighbor algorithm(86.89%) for agricultural ontology construction.

• 한국토양비료학회지
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• 제48권4호
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• pp.295-304
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• 2015

To develop a technique for efficient management of fertility for cucumber in greenhouse, a quick test method to quantify nitrate ($NO_3{^-}$) content in soil solution and leaf petiole juice using a simple instrument that are easy to use for farmers was investigated. N fertilizer (urea) was applied at 0, 50, 100 and 200% levels of the recommended application rate from 30 days after transplanting to harvest by soil fertigation treatments. Stable results were obtained from analysis of nitrate ($NO_3{^-}$) using top $10^{th}$ or $11^{th}$ leaf petioles collected between 10 to 11 am in the morning. Under the semiforcing culture, $NO_3{^-}$ content of leaf petiole juice was highest at 60 days after transplanting (DAT) at all fertigation treatments. Appropriate $NO_3{^-}$content of leaf petiole juice was $2,418{\pm}78{\sim}2,668{\pm}118$ at 45 DAT, $3,032{\pm}90{\sim}3,332{\pm}63$ at 60 DAT, $2,709{\pm}50{\sim}3,158{\pm}155$ at 75 DAT, $2,535{\pm}49{\sim}2,907{\pm}83$ at 90 DAT, and $2,242{\pm}48mg\;L^{-1}$ at 105 DAT. In addition, appropriate $NO_3{^-}$ content of soil solution was $167{\pm}9{\sim}212{\pm}15$ at 45 DAT, $83{\pm}10{\sim}112{\pm}12$ at 60 DAT, $49{\pm}3{\sim}92{\pm}6$ at 75 DAT, $71{\pm}9{\sim}103{\pm}9$ at 90 DAT, and $73{\pm}9mg\;L^{-1}$ at 105 DAT. The cucumber yield at 100% N level of fertigation was $7,770kg\;10a^{-1}$ and no difference in yield was found at 200% N level of fertigation. However, there was 12% decrease in yield at 50% N fertigation and, 17% decrease at 0% N fertigation. Under retarding culture, $NO_3{^-}$ concentration of leaf petiole juice was highest at 55 days after transplanting (DAT) at all fertigation treatments. Appropriate $NO_3{^-}$ content of leaf petiole juice was $2,464{\pm}102{\sim}2,651{\pm}33$ at 45 DAT, $3,025{\pm}71{\sim}3,314{\pm}84$ at 55 DAT and $2,488{\pm}92mg\;L^{-1}$ at 65 DAT, respectively. Appropriate $NO_3{^-}$ content of soil solution was $111{\pm}10{\sim}155{\pm}14$ at 45 DAT, $93{\pm}7{\sim}147{\pm}14$ at 55 DAT, $67{\pm}4mg\;L^{-1}$at 65 DAT, respectively. The cucumber yield at 50% N fertigation was not different from $1,697kg\;10a^{-1}$ of 100% N fertigation level and even with that of the 200% N fertigation. However, there was 21% decrease in yield at 0% N fertigation.

• 농촌지도와개발
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• 제13권1호
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• pp.69-83
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• 2006

This study aims to develop useful programs, which would promote the economic activities of rural elderly and their living standard as the silver population is growing in the society, to present the direction of policy related to the elderly for governmental agencies, and make it available as data that can be accessed by civil servants, in charge of elderly-related matters and currently serving at city office and municipal and county agricultural technique center, so that they can provide education to the elderly. For this, first, the economic condition of the rural elderly and their requirements have to be diagnosed. Second, we developed a program that specially aimed at improving their economic activities. To develop of program, a survey questionnaire was administered with the 881 elderly over 60 years old who live in 110 rural villages. Face to face interview was carried out by professional interviewer. The result was once posted in the 2nd issue of volume 14th of this journal in 2004 with the title of "Study of the rural elderly's activities and needs of economics." Based on such result of study, we developed the program to provide jobs to the rural elderly that are suitable for them. 2 types programs, which differ from each other depending on the subject of implementing the welfare of the elderly, were developed: first, "program to create jobs for rural elderly at the policy supporting level, which requires the government to drive forward, and second, 'program to provide education to rural elderly at the social level' to foster them as competent human resources."

• 농촌지도와개발
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• 제21권2호
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• pp.29-56
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• 2014

본 연구는 오디 시설재배기술이라는 신기술을 수용하지 않은 농가 200명을 대상으로 혁신확산이론과 기술수용이론을 결합한 연구모델을 통해 각각의 요인들이 신기술 수용 및 확산에 미치는 영향 정도를 분석하기 위하여 기술수용모형을 바탕으로 유용성, 용이성, 위험성이라는 내생변수를 통해 신기술 수용 및 확산에 영향을 미치는 외부요인간의 관계를 구조방정식 모형 분석을 실시하여 검증하였다. 분석결과는 채택된 지표중에서 인지된 유용성에 영향을 미치는 개인의 혁신성과 인지된 위험성 변수의 교육지원 품질, 기술지원 품질과 자금지원정도 지표는 부(-)의 영향을 미치고 나머지 지표들은 정(+)의 영향을 미치는 것으로 나타났다. 분석결과를 바탕으로 오디 시설재배의 조기확산을 위해서는 먼저 기술보급 담당자의 전문성과 기술수준을 높이고, 신기술 수용농가와 더불어 애로사항 발생에 따른 해결을 위한 인적 네트워크를 구축하여 운영할 필요가 있다. 다음은 오디재배 농가들은 시설재배기술이 쉽지만 시설투자에 대한 부담 때문에 유용성에는 회의적인 반응을 보이므로 시설투자비에 대한 개인별 맞춤형 자금보조가 필요하다. 끝으로 기술수용에 부정적인 농가들을 대상으로 재배기술교육과 신기술 수용현장견학과 경영성과에 대한 홍보를 지속적으로 실시하면 빠른 시일 내에 보급이 가능할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제25권2호
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• pp.240-247
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• 2012

Dietary supplementation with conventional linted cottonseed hulls (LCSH) is a common practice in livestock production all over the world. However, supplementation with mechanically delinted cottonseed hulls (DCSH) and cottonseed linter residue (CLR) is uncommon. Cottonseed by-products, including LCSH, DCSH and CLR, were assessed by chemical analysis, an in situ nylon bag technique, an in vitro cumulative gas production technique and in vitro enzyme procedure. The crude protein (CP) content of CLR (302 g/kg dry matter (DM)) was approximately 3 times that of LCSH and 5 times that of DCSH. The crude fat content was approximately 3 times higher in CLR (269 g/kg DM) than in LCSH and 4 times higher than in DCSH. Neutral detergent fibre (311 g/kg DM) and acid detergent fibre (243 g/kg DM) contents of CLR were less than half those of DCSH or LCSH. Metabolisable energy, estimated by in vitro gas production and chemical analyses, ranked as follows: CLR (12.69 kJ/kg DM)>LCSH (7.32 kJ/kg DM)>DCSH (5.82 kJ/kg DM). The in situ degradation trial showed that the highest values of effective degradability of DM and CP were obtained for CLR (p<0.05). The in vitro disappearance of ruminal DM ranked as follows: CLR>LCSH>DCSH (p<0.05). The lowest digestibility was observed for DCSH with a two-step in vitro digestion procedure (p<0.05). The potential gas production in the batch cultures did not differ for any of the three cottonseed by-product feeds. The highest concentration of total volatile fatty acids was observed in CLR after a 72 h incubation (p<0.05). The molar portions of methane were similar between all three treatments, with an average gas production of 22% (molar). The CLR contained a higher level of CP than did LCSH and DCSH, and CLR fermentation produced more propionate. The DCSH and LCSH had more NDF and ADF, which fermented into greater amounts of acetate.