• 농촌계획
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• 제12권1호
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• pp.37-48
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• 2006

The objectives of this study were to develop an evaluation method of regional vulnerability to agricultural drought and to classify the vulnerability patterns. In order to test the method, 24 city or county areas of Gyeonggi-do were chose. First, statistic data and digital maps referred for agricultural drought were defined, and the input data of 31 items were set up from 5 categories: land use factor, water resource factor, climate factor, topographic and soil factor, and agricultural production foundation factor. Second, for simplification of the factors, principal component analysis was carried out, and eventually 4 principal components which explain about 80.8% of total variance were extracted. Each of the principal components was explained into the vulnerability components of scale factor, geographical factor, weather factor and agricultural production foundation factor. Next, DVIP (Drought Vulnerability Index for Paddy), was calculated using factor scores from principal components. Last, by means of statistical cluster analysis on the DVIP, the study area was classified as 5 patterns from A to E. The cluster A corresponds to the area where the agricultural industry is insignificant and the agricultural foundation is little equipped, and the cluster B includes typical agricultural areas where the cultivation areas are large but irrigation facilities are still insufficient. As for the cluster C, the corresponding areas are vulnerable to the climate change, and the D cluster applies to the area with extensive forests and high elevation farmlands. The last cluster I indicates the areas where the farmlands are small but most of them are irrigated as much.

• 한국기후변화학회지
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• 제6권3호
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• pp.223-231
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• 2015

Although a considerable part of climate change can be explained by temperature change, hydrological change such as precipitation, evapotranspiration, and runoff impact more on society. For the ascertain a hydrological change in agriculture sector, this study estimate evapotranspiration of cropland in the Korean peninsula, and then to assess the drought severity in the past 30 years through the estimated potential evapotranspiration and observed precipitation. The potential evapotranspiration is estimated by EPIC model and Penman-Monteith method and the drought severity in cropland of the Korean peninsula is assessed using Normalized Precipitation Evapotranspiration Index (NPEI) based on the difference in precipitation and potential evapotranspiration. In North Korea, the estimated evapotranspiration tends to increase even though a significant change is not found due to the change of climate. Although a time series change in drought severity in the past 30 years is not pronounced, a deviation by year and difference between South and North Korea is certain. One reason of this is difference in precipitation and evapotranspiration change according to the latitude. The result including expansion of facilities for water management in North Korea can be used for agricultural decision making, as well as base data of climate change adaptation.

• Plant Breeding and Biotechnology
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• 제6권4호
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• pp.354-362
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• 2018

Maize has high food and industrial value, whereas has difficulties in research because of their complex and huge size genome. Nested association mapping (NAM) was constructed to better understand maize genetics. However, most studies were conducted using the reference genome B73, and only a few studies were conducted on tropical maize. Ki3, one of the founder lines of the NAM population, is a tropical maize. We analyzed the genetic characteristics of Ki3 by using RNA sequencing and bioinformatics tools for various genetic studies. As results, a total of 30,526 genes were expressed, and expression profile were constructed. A total of 1,558 genes were differentially expressed in response to drought stress, and 513 contigs of them come from de novo assemblies. In addition, high-density polymorphisms including 464,930 single nucleotide polymorphisms (SNPs), 21,872 multiple nucleotide polymorphisms (MNPs) and 93,313 insertions and deletions (InDels) were found compared to reference genome. Among them, 15.0 % of polymorphisms (87,838) were passed non-synonymous test which could alter amino acid sequences. The variants have 66,550 SNPs, 5,853 MNPs, and 14,801 InDels, also proportion of homozygous type was higher than heterozygous. These variants were found in a total of 15,643 genes. Of these genes, 637 genes were found as differentially expressed genes (DEGs) under drought stress. Our results provide a genome-wide analysis of differentially expressed genes and information of variants on expressed genes of tropical maize under drought stress. Further characterization of these changes in genetic regulation and genetic traits will be of great value for improvement of maize genetics.

• 한국유기농업학회지
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• 제24권4호
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• pp.787-795
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• 2016

The purpose of this study was to assess drought tolerance of groundcover plants for extensive green roof. Form July to November 2013, plant height, chlorophyll content, soil moisture, evapotranspiration and survival rate was measured. As results, after unirrigation started, Aster koraiensis reached 0% of soil moisture earliest followed by Sedum kamtschaticum, Hemerocallis fulva, Hylotelephium spectabile, Iris sanguinea, Hosta longipes and control. Among the plants, A. koraiensis withered earliest on 19th day of unirrigation experiment, followed by H. longipes and H. fulva (27th day); and I. sanguinea (29th day). S. kamtschaticum and H. spectabile survived even after 120th day of the experiment. As for chlorophyll content, I. sanguinea showed constant values in early stage than rapidly decreased right before its withering. Chlorophyll content of A. koraiensis and H. fulva showed rapid decrease from the beginning, while that of H. spectabile and S. kamtschaticum showed continuous reduction for first 30 days and the reduction was slowed down since then. In conclusion, H. longipes, I. sanguinea and H. fulva were found most applicable for extensive green roof considering scenic aspect.

• Current Research on Agriculture and Life Sciences
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• 제31권2호
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• pp.139-147
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• 2013

This study analyzed agricultural water distribution systems for the utilization of water demand-oriented water supply systems. Three major TM/TC(telemeter/telecontrol) districts of agricultural water management were selected for analyzing the characteristics of the water distribution systems. In addition, the characteristics of the water supply systems for general water supply zones based on irrigation facilities were also investigated, along with the case of special water management during the drought season. As a result, high annual and monthly variations were observed for the water supply facilities, including the reservoirs and pumping stations. In particular, these variations were more obvious during the drought season, depending on the type of facility. The operations of the pumping stations and weirs were more sensitive to the stream levels than the reservoirs, and the smaller reservoirs were influenced more than the larger reservoirs. Therefore, a water-demand-oriented water supply system should consider the existing general practices of water management in the agricultural sector, and focus on achieving a laborsaving system rather than water conservation in the case of reservoirs. Equal water distribution from the start to the end point of irrigation channels could be an effective solution for managing pumping stations.

• 농업과학연구
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• 제50권4호
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• pp.759-771
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• 2023

Plant growth-promoting rhizobacteria (PGPR) are naturally occurring bacteria that intensively colonize plant roots and are crucial in promoting the crop growth. These beneficial microorganisms have garnered considerable attention as potential bio-inoculants for sustainable agriculture. PGPR directly interacts with plants by providing essential nutrients through nitrogen fixation and phosphate solubilization and accelerating the accessibility of other trace elements such as Cu, Zn, and Fe. Additionally, they produce plant growth-promoting phytohormones, such as indole acetic acids (IAA), indole butyric acids (IBA), gibberellins, and cytokinins.PGPR interacts with plants indirectly by protecting them from diseases and infections by producing antibiotics, siderophores, hydrogen cyanide, and fungal cell wall-degrading enzymes such as glucanases, chitinases, and proteases. Furthermore, PGPR protects plants against abiotic stresses such as drought and salinity by producing 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and modulating plant stress markers. Bacteria belonging to genera such as Bacillus, Pseudomonas, Burkholderia, Pantoa, and Enterobacter exhibit multiple plant growth-promoting traits, that can enhance plant growth directly, indirectly, or through synergetic effects. This comprehensive review emphasizes how PGPR influences plant growth promotion and presents promising prospects for its application in sustainable agriculture.

• 한국산림과학회지
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• 제50권1호
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• pp.25-28
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• 1980

본 연구(硏究)는 잣나무, 젓나무, 은행나무의 내건성(耐乾性)의 관계((関係)하는 수분특성(水分特性)의 저요인(諸要因)을 pressure chamber technique에 의해 1980년(年) 8월(月) 10일(日)부터 9월(月) 4일(日)에 걸쳐 측정, 그 결과(結果)를 고찰(考察)한 것이다. 지엽(枝葉)의 최대포수시(最大飽水時)의 침투압(浸透圧)(${\pi}_0$), 초기원형질분리점(初期原形質分離点)의 침투압(浸透圧)(${\pi}_p$) 및 상대함수율(相対含水率)(RWC), 총(総) symplasmic water(Vo)에 대한 초기원형질분리점(初期原形質分離点)의 생세포군(生細胞群) 함수량(含水量)(Vp)과의 비(比)(Vp/Vo)등을 비교(比較)할때, 젓나무는 잣나무보다 선천적(先天的)으로 내건(耐乾)에 강(強)한 지엽(枝葉)의 수분특성(水分特性)을 갖고 있으며, 은행나무는 이들 양수종(両樹種) 보다 강(強)한 내건성(耐乾性)임을 시사(示唆)했다.

• 한국농공학회논문집
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• 제66권2호
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• pp.35-52
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• 2024

This study conducted an assessment of potential impacts on the drought in agricultural reservoirs using the recently proposed SSP (Shared Socioeconomic Pathways) scenarios by IPCC (Intergovernmental Panel on Climate Change). This study assesses the potential impact of climate change on agricultural water resources and infrastructure vulnerability within Gyeongsangnam-do, focusing on 15 agricultural reservoirs. The assessment was based on the KRC (Korea Rural Community Corporation) 1^st vulnerability assessment methodology using RCP scenarios for 2021. However, there are limitations due to the necessity for climate impact assessments based on the latest climate information and the uncertainties associated with using a single scenario from national standard scenarios. Therefore, we applied the 13 GCM (General Circulation Model) outputs based on the newly introduced SSP scenarios. Furthermore, due to difficulties in data acquisiton, we reassessed potential impacts by redistributing weights for proxy variables. As a main result, with lower future potential impacts observed in areas with higher precipitation along the southern coast. Overall, the potential impacts increased for all reservoirs as we moved into the future, maintaining their relative rankings, yet showing no significant variability in the far future. Although the overall pattern of potential impacts aligns with previous evaluations, reevaluation under similar conditions with different spatial resolutions emphasizes the critical role of meteorological data spatial resolution in assessments. The results of this study are expected to improve the credibility and accuracy formulation of vulnerability employing more scientific predictions.

• 농업생명과학연구
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• 제50권1호
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• pp.33-43
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• 2016

다양한 생리적 인자를 사용하여 참느릅나무 등 총 26 종의 식물체를 대상으로 내건성을 검정하였다. 새, 도깨비가지, 긴담배풀은 수분 중단 8 일 후부터 시들었다. 매듭풀, 비수리와 참느릅나무는 수분 중단 9-10 일 후부터 80% 이상이 시들었다. 매듭풀은 수분 중단 10 일후부터, 비수리와 참느릅나무는 수분중단 11 일후부터 90% 이상이 시들었다. 수분 공급을 중단하는 처리를 통하여 새, 도깨비가지, 참느릅나무, 매듭풀, 비수리와 참느릅나무는 내건성 식물종으로 확인할 수 있었다. 그 가운데 차풀의 증산률은 0.042ml/㎠·4hr 로 가장 높은 반면에, 비수리와 참느릅나무는 각각 0.005 와 0.010ml/㎠·4hr 의 낮은 값을 나타내었다. 생리적 인자들의 테스트에서, 잎 면적와 증산률은 식물종마다 다르게 나타났다. 참느릅나무의 단위 증산률은 다른 식물종들과 비교하여 낮은 값을 가졌다. 새, 매듭풀, 비수리와 참느릅나무는 높은 상대수분함량을 가졌으며, 낮은 상대수분손실량을 보였다. 이러한 결과를 바탕으로 내건성 식물은 비수리와 참느릅나무로 최종 확인되었고, 생리적 인자를 이용한 내건성 식물을 선발 시스템이 가능함을 보여 주었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.91-91
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• 2017

Drought is the most serious abiotic stress limiting rice production. However, little progress has been made in the genetic analysis of drought tolerance, because it is a complex trait controlled by a number of genes and affected by various environmental factors. In here, we screened 218 rice genetic resources for drought tolerance at vegetative stage and selected 32 highly drought tolerant varieties in greenhouse. Under rain-fed conditions, Grain yield of Nagdong was decreased by 53.3% from 517 kg/10a to 241 kg/10a when compare to irrigation condition. By comparison, grain yield of Samgang was decreased by 23.6% from 550 kg/10a to 420 kg/10a. The variety Samgang exhibited strong drought tolerance and stable yield in rain-fed conditions and was selected for further study. To identify QTLs for drought tolerance, we examined visual drought tolerance (VDT) and relative water content (RWC) using a doubled haploid (DH) population consisted of 101 lines derived from a cross between Samgang (a drought tolerance variety) and Nagdong (a drought sensitive variety). Three QTLs for VDT were located on chromosomes 2, 6, and 11, respectively, and explained 41.8% of the total phenotypic variance. qVDT2, flanked by markers RM324 and S2016, explained 8.8% of the phenotypic variance with LOD score of 3.3 and an additive effect of -0.6. qVDT6 was flanked by S6022 and S6023 and explained 12.7% of the phenotypic variance with LOD score of 5.0 and an additive effect of -0.7. qVDT11, flanked by markers RM26765 and RM287, explained 19.9% of the phenotypic variance with LOD score of 7.1 and an additive effect of -1.0. qRWC11 was the only QTL for RWC to be identified; it was in the same locus as qVDT11. qRWC11 explained 19.6% of the phenotypic variance, with a LOD score of 4.0 and an additive effect of 9.7. To determine QTL effects on drought tolerance in rain-fed paddy conditions, seven DH lines were selected according to the number of QTLs they contained. Of the drought tolerance associated QTLs, qVDT2 and qVDT6 did not affect tiller formation, but qVDT11increased tiller number. Tiller formation was most stable when qVDT2 and qVDT11 were combined. DH lines with both of these drought tolerance associated QTLs exhibited the most stable tiller formation. These results suggest that qVDT11 is important for drought tolerance and stable tiller formation under drought stress condition in field.