• 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.

• 한국농공학회논문집
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• 제60권3호
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• pp.1-13
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• 2018

Recently, the frequency and intensity of drought have been increasing due to the sudden abnormal climate in Korea. The occurrence of agricultural drought has been steadily increasing from 5 times in the 1980s to 2000s in 20 years, 6 times in the 10 years from 2000 to 2010, and 4 times in the recent period from 2011 to 2015. Therefore, this study analyzed the effect of water shortage caused by drought by improving the function of agricultural reservoir. The target area analyzed the data such as "Comprehensive Information System for Rural Water" operated by Korea Rural Community Corporation. As a result, we selected the target area as Wanju - gun, Jeollabuk - do in consideration of the rate of water storage compared with the normal 25 years, the completion year of the facility, the area of coverage per reservoir site and the low capacity. As a result of evaluating the improvement effect of agricultural facilities, it was analyzed that the irrigation area increased by about 25.7% when the water level was increased by 1m and the irrigation area increased by about 51.3% when the water level was increased by 2m. The results of the drought impact assessment after improving the function of the agricultural facilities were analyzed that it was effective to improve the function after more than 4m depth.

• 대한토목학회논문집
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• 제29권2B호
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• pp.181-191
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• 2009

본 연구에서는 2007년 IPCC AR4와 함께 제시된 SRES A2 시나리오를 이용해서 기후변화가 한반도 가뭄에 미치는 영향을 평가하기 위한 방안을 제시하고자 한다. IPCC는 DDC를 통해서 총 24개의 기후모형의 결과를 월 단위로제공하고 있다. 이 중 노르웨이 BCCR의 BCM2 모형과 NCEP 자료를 이용하여 최근린법(K-NN)과 인공신경망(Artificial Neural Network)이론을 적용함으로써, 온도와 강수량을 기상청 산하 서울지점으로 축소하였다. 최근린법의 경우, 온도와 강수량 모두를 축소하는 것이 가능하였지만, 인공신경망이론을 적용하여 축소할 경우, 온도는 비교적 잘 축소하였으나 강수량의 경우는 발산하는 결과를 보였다. 마지막으로 기후변화가 가뭄에 미치는 영향을 평가하기 위해서 최근린법으로부터 축소된 월 단위 강수량을 이용하여 서울지점의 표준강수지수를 산정하였다. BCM2 모형에 의하면 서울지점의 경우, 미래에는 전반적으로 온도가 증가하고 가뭄의 지속기간이 길어짐에 따라 가뭄이 더욱더 심각하게 된다는 결과를 예측하였다.

• 한국작물학회지
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• 제47권1호
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• pp.48-53
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• 2002

To investigate the changes in the composition and pool size of carbohydrates under drought stress, white clover (Triforium repens L.) were exposed to -0.04 Mpa(well-watered, control) or to -0.12 Mpa (drought-stressed) of soil water potential during 28 days. Dry weight of leaves in drought-stressed plants was remarkably decreased by 45% within 14 days and 74% within 28 days compared to those of the control. Glucose concentration in drought-stressed plants was increased, while that of control was slightly decreased or remained at same level throughout experimental period. Fructose and sucrose concentrations in leaves were not significantly changed for drought-stressed plants, but those of the control were significantly decreased on plant after 14 days. Fructose and sucrose concentrations in stolon of control plants were sharply decreased, while that of drought-stressed plants was less varied. Those concentrations in roots were generally increased in drought-stressed plants. The concentration of total soluble sugars at 28 day was 438.0 and 632.6 mg $g^{-l}$ dwt. in control and drought stressed plants, respectively. Starch concentration of stolon and roots of control plants was significantly increased to 2.0 and 1.4 times of initial level, respectively, whereas those of drought stressed plants was nearly same level or slightly decreased compared to initial level.l.

• 한국작물학회지
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• 제47권2호
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• pp.95-101
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• 2002

To investigate the changes in the composition and pool size of nitrogen metabolites under drought stress, white clover (Trifolium repens L.) were exposed to -0.04MPa (well-watered, control) or to -0.12MPa (drought-stressed) of soil water potential during 28 days. Dry weight of leaves in drought-stressed plants was remarkably decreased by 45% and 74% within 14 days and 28 days, respectively, compared with control. For nitrate concentration after 28 days of treatment, a significant difference (1.6 times higher in drought-stressed plants) was observed only in stolon. NH$_3$-NH$_4$$^{+}$ concentration in all three organs of drought-stressed plants linearly increased to more than 1.6 times higher level at 28 day when compared to the initial level (day 0), while the increasing rate in control was much less than that of drought-stressed plants. Proline concentrations in drought-stressed plants remarkably increased and reached to 7, 13 and 17 times higher level at 28 day compared to control. Protein concentration in leaves of drought-stressed plants tended to decrease, while it slightly increased during the first 14 days and reached a plateau afterward in control. There was not significant difference in the proteins concentration of stolon and roots throughout experimental period. On SDS-PAGE analysis, two major proteins specifically induced by drought stress (16-kD and 18-kD) were detected in stolon.n.

• 한국물환경학회지
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• 제37권5호
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• pp.369-380
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• 2021

In this work, we analyzed the effects of drought on the water temperature (WT) of Nakdong river basin major river sections using Standardized Precipitation Index (SPI) and WT data. The analysis was carried out on a seasonal basis. After calculating the optimal time scale of the SPI through the correlation between the SPI and WT data, we used the copula theory to model the joint probability distribution between the WT and SPI on the optimal time scale. During spring and fall, the possibility of environmental drought caused by high WT increased in most of the river sections. Notably, in summer, the possibility of environmental drought caused by high WT increased in all river sections. On the other hand, in winter, the possibility of environmental drought caused by low WT increased in most river sections. From the risk map, which quantified the sensitivity of WT to the risk of environmental drought, the river sections Nakbon C, Namgang E, and Nakbon K showed increased stress in the water ecosystem due to high WT when drought occurred in summer. When drought occurred in winter, an increased water ecosystem stress caused by falling WT was observed in the river sections Gilan A, Yongjeon A, Nakbon F, Hwanggang B, Nakbon I, Nakbon J, Nakbon K, Nakbon L, and Nakbon M. The methodology developed in this study will be used in the future to quantify the effects of drought on water quality as well as WT.

• 한국지하수토양환경학회지:지하수토양환경
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• 제26권1호
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• pp.76-87
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• 2021

Groundwater is considered to be the best water resource to solve water shortage problems during drought periods. Even though excessive pumping (overdraft) during short-period may give an unprofitable effect on groundwater hydrology, it has a primary role to solve a lack of water resources and to maintain incomes of farmers. This study evaluated maximum irrigation amounts of groundwater to each local-government and province during drought periods. Maximum irrigation amounts of groundwater were evaluated using cumulative groundwater usage data of each local-government during normal and drought years. Maximum irrigation amounts of groundwater during drought periods would be roughly identified as approximately 1.3 times more than the exploitable amounts of groundwater resources for each local-government. Drawdown-limitation depth on groundwater levels at each monitoring well was determined by transforming the maximum irrigating amounts into degree of change on levels. Universal limitation depth of drawdown on groundwater levels was evaluated to be approximately three times of annual fluctuating range on groundwater levels for each monitoring well. Systematic response on groundwater demands with abiding by drawdown-limitation depth can attain an optimal irrigation of groundwater resources during short-term drought.

• 한국작물학회지
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• 제59권1호
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• pp.54-58
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• 2014

물 자원이 제한되거나 관수 설비가 갖추어지지 않은 곳에서 찰옥수수의 한발 피해를 줄이고자, 종실용 옥수수에 대한 수분 스트레스 경감 효과가 보고되어진 살리실산과 앱시식산의 처리 효과를 살펴보았다. 출웅기 9일 전부터 출웅 후 14일까지 관수를 중단하였으며, 생장조절제는 출웅기에 1회 처리하였다. 살리실산과 앱시식산의 처리 농도는 각각 0.5 mM과 0.1 mM이었다. 한발 처리에 의해 ASI가 3.0~3.3일 늘어났으며, 간장은 47~51 cm, 이삭장은 4.6~5.0 cm, 이삭경은 4.4~5.3 mm, 열수는 1.5~2.0개, 수량은 2.4~2.5 Mg/ha 줄었다. 살리실산과 앱시식산의 처리에 의한 한발 피해의 경감 효과는 뚜렷하지 않았다. 찰옥수수에 대한 살리실산과 앱시식산의 한해 경감 효과를 위해서는 수분 부족 스트레스를 받기 이전에 처리하거나, 저농도로 몇차례에 나누어 처리하는 것이 필요한 지에 대한 추후 검토가 필요하다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.231-231
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• 2017

Drought limits rice production under upland condition. This study quantified the effect of rhizobacteria inoculation on rice root system developmental response to drought and its role in maintaining high soil water use, and dry matter production under drought using NSIC Rc192 (rainfed lowland rice variety). The source of inoculant was Streptomyces mutabilis, a recently isolated rhizobacteria containing plant growth promoting compounds such as ACC deaminase, indole-3-acetic acid and phosphatase (Cruz et al., 2014, 2015). In the first experiment, pre-germination inoculation of seeds with S. mutabilis significantly increased the shoot and root (radicle) length as well as root hair lengths, relative to the non-inoculated control. In the second experiment, rice plants inoculated with S. mutabilis and grown in rootbox with soil generally had greater total root length under drought regardless of the timing of inoculations, relative to the non-inoculated control. Consequently, improved root system development contributed to the increase in soil water uptake under drought and thus, dry matter production. Among inoculation treatments, one-time inoculation of S. mutabilis either at pre-germination or pre-drought stress at 14 days after sowing (DAS), had significantly greater shoot dry matter production than three-time inoculation at pre-germination, at thinning (3 DAS) and at pre-drought (14 DAS). This study demonstrated the effectiveness of rhizobacteria (S. mutabilis) containing growth promoting compounds for enhancing drought dehydration avoidance root traits and improving the growth of rice plants under drought condition.

• 대한토목학회논문집
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• 제38권3호
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• pp.387-393
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• 2018

기후변화의 영향으로 극심한 가뭄에 의한 피해가 증가하고 있으며, 이러한 피해를 줄이기 위하여 극한 가뭄에 대한 정량적인 분석이 필요하다. 따라서 본 연구에서는 극한 가뭄의 위험도에 대한 정량적 분석을 위해 임계수준방법을 측우기 강우자료, 관측 강우자료, 미래 기후변화 시나리오 강우 자료에 적용하여 가뭄사상을 정의하고 가뭄의 지속기간과 심도를 도출하였다. 또한, 코플라 함수를 활용하여 가뭄 지속기간 및 심도를 동시에 고려하는 이변량 가뭄빈도해석을 실시하였다. 이변량 가뭄빈도곡선을 바탕으로 과거 현재 미래에 대한 위험도를 산정했으며, 과거 및 현재를 기준으로 미래의 극한 가뭄에 대한 위험도를 분석하였다. 그 결과 과거 및 현재에 비해 미래의 평균 가뭄 지속기간은 짧게 나타났으나 평균 가뭄 심도는 매우 크게 나타났다. 따라서 미래에는 짧은 기간의 심한 가뭄들이 발생할 것으로 예측된다. 또한, 최대가뭄의 위험도를 분석한 결과 미래의 최대 가뭄 위험도는 과거 및 현재에 비해 각각 1.39~1.94배, 1.33~1.81배 큰 것으로 확인되었다. 최종적으로 미래에서 과거 및 현재의 기왕최대 가뭄 이상의 극한 가뭄위험도는 0.989와 1.0 사이의 범위를 가지는 것으로 나타나, 미래에는 극한 가뭄의 발생확률이 높은 것으로 판단된다.