• Korean Journal of Organic Agriculture
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• v.26 no.2
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• pp.217-232
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• 2018

Drought is a major obstacle to high agricultural productivity, worldwide. In drought, it is usually presented by the simultaneous action of high temperature and drying. Also there are negative effects of plant growth under drying conditions. In this study, the effect of Bacillus velezensis YP2 on plant growth-promotion and soil drying stress tolerance of kale plants, Brassica oleracea var. alboglabra Bailey, were investigated under two different conditions; greenhouse and field environments. Root colonization ability of B. velezensis YP2 was also analysed by using plating culture method. As a result of the greenhouse test, the YP2 strain significantly promoted the growth of kale seedlings in increasement of 26.7% of plant height and 142.2% of shoot fresh weight compared to control. B. velezensis YP2 have the mitigation effect of drying injury of kale by decreasing of 39.4% compared to control. In the field test, B. velezensis YP2 strain was also found to be effective for plant growth-promotion and mitigation of drying stress injury on kale plants. Especially, relative water contents (RWC; %) were higher in B. velezensis YP2 treated kales than in control at 7, 10, 14 day after non-watering. The root colonization ability of YP2 strain was continued at least for 21 days after soil drenching treatment of B. velezensis YP2. Our result suggested that enhancement of plant growth and drying injury reduction of kale plants were involved in kale root colonization by B. velezensis YP2, which might be contributed to increasing water availability of plants. Consequentially, the use of B. velezensis YP2 might be a beneficial influence for improving productivity of kale plants under drying stress conditions.

• Journal of Korean Society of Forest Science
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• v.61 no.1
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• pp.8-14
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• 1983

This study was to diagnose the ontogenetic ability of drought tolerance in trees, and was to investigate the seasonal changes in tissue-water relations parameters, ${\pi}_o$, ${\pi}_p$, $E_{max}$, $N_s/DW$, $V_o/W_s$ and $RWC_{(tlp)}$, obtained from P-V curves on the Pinus koraiensis and Abies holophylla shoots. The results obtained are as follows; 1) Seasonal changes of original osmotic pressure at maximum turgot, ${\pi}_o$, were -1.2 to -1.6 MPa in Pinus koraiensis and -1.4 to -1.7 MPa in Abies holophylla. 2) Seasonal changes of osmotic pressure at incipient plasmolysis, ${\pi}_p$, were -1.8 to -2.1 MPa in Pinus koraiensis and -1.6 to -2.1 MPa in Abies holophylla. 3) Seasonal changes of relative water content at incipient plasmolysis, $RWC_{(tlp)}$, were 70 to 77% in Pinus koraiensis and 69 to 85% in Abies holophylla. 4) Seasonal changes of maximum bulk modulus of elasticity at maximum hydration, $E_{max}$, were 2.2 to 6.3 MPa in Pinus koraiensis and 3.1 to 7.9 MPa in Abies holophylla. 5) Seasonal changes of number of osmoles of solute in symplasm versus dry weight, $N_s/DW$, were 0.5 to 1.3 in Pinus koraiensis and 0.3 to 1.0 in Abies holophylla. 6) Seasonal changes of original osmotic water volume versus total water volume (symplasmic and apoplastic water), $V_o/W_s$, were 55 to 65%r in Pinus koraiensis and 40 to 65% in Abies holophylla. Consequently, as the comparative values of ${\pi}_o$, ${\pi}_p$, $E_{max}$, $N_s/DW$, $V_o/W_s$, and $RWC_{(tlp)}$, it might be suggested that Abies holophylla shoot could have more or less a greater ability of drought tolerance as compared with Pinus koraiensis shoot.

• Journal of the Korean Institute of Landscape Architecture
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• v.39 no.1
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• pp.117-123
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• 2011

This study aims to suggest a suitable soil thickness and soil mixture ratio of a green roof system by verifying the growth of Chrysanthemum zawadskii var. coreanum as affected by different green roof systems using rainwater. The experimental planting grounds were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios (SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$) and with excellent drought tolerance. Ornamental value Chrysanthemum zawadskii var. coreanum was planted. The change in plant height, green coverage ratio, chlorophyll content, fresh weight, dry weight, and dry T/R ratio of Chrysanthemum zawadskii var. coreanum were investigated from April to October 2009. For 15cm soil thickness, the plant height of Chrysanthemum zawadskii var. coreanum was not significantly different as affected by the soil mixing ratio. However, it was found to be higher in the amended soil mixture, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ and $P_4P_4L_2$ than in the sandy loam soil, as it was SL overall. For 25cm soil the plant height differences were in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was observed not to be different by soil mixing ratio with soil thickness of 15cm, but, the lowest green coverage ratio in the SL. In the 25cm soil thickness, the green coverage ratio was 86-89% with a good coverage rate overall. The change in chlorophyll contents with 15cm soil thickness was found to be the highest in the SL treatment and the lowest in the $P_5P_3L_2$ treatment. For 25cm thickness, the highest value was in the $P_4P_4L_2$ and SL, and the lowest in the$P_7P_1L_2$. Fresh weight and dry weight were larger in soil with 25cm thickness. Therefore, the growth of Chrysanthemum zawadskii var. coreanum as affected by a different green roof system for using rainwater was higher in soil with 25cm thickness than 15cm, and in PPL amended soil than in sandy loam.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.51-56
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• 2015

The objective of this study was to evaluate the effect of silicate fertilizer on growth, physiology and abiotic stress tolerance of Chinese cabbage seedlings. Five silicate concentrations (8, 16, 32, 64, and 128mM) and control (non-treatment) were applied to Chinese cabbage seedlings twice a week. Three weeks after application of silicate treatment, seedlings were used for treating abiotic stresses and were assessed for growth and physiological characteristics. Growth parameters significantly increased in 8, 16, and 32mM treatments except 64 and 128mM. Total root surface area, total root length, and number of root tips increased in 8, 16 and 32mM treatments, but they decreased in treated seedlings with 64 and 128mM of silicate. The highest growth parameters and root morphology were observed in 8mM treatment. As for the effect on the seedling physiology, transpiration rates decreased while stomatal diffusive resistance increased to increasing silicate concentration. The application of silicate reduced the electrical conductivity, heating and chilling injury index at high and low temperatures. Silicate enhanced drought tolerance of Chinese seedlings by delaying the starting time of wilting point. The starting time of wilting point in the control was 3 days after discontinuation of irrigation, while in the 8, 64 and 128mM of silicate treatments were 4 days, and the 16 and 32mM treatments were 5 days. All plants were wilted after 5 days in control without irrigation whereas it showed in 8mM treatment after 6 days, in 16, 32, 64, 128mM treatments after 7 days.

• Journal of Plant Biotechnology
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• v.44 no.1
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• pp.69-75
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• 2017

Dormancy-associated protein (DRM) is involved in the dormancy physiology of plants and is conserved in almost all plant species. Recent studies found that DRM genes are involved in the abiotic stress response, and characterization studies of these genes have been conducted in several plants. However, few studies have focused on DRM genes in woody plants. Therefore, in this study, cDNA coding for DRM (PagDRM1) was isolated from poplar (Populus alba ${\times}$ P. glandulosa), and its structure and expression characteristics were investigated. PagDRM1 encodes a putative protein composed of 123 amino acids, and the protein contains two conserved domains (Domain I and Domain II). PagDRM1 is present as one or two copies in the poplar genome. Its expression level was highest in the stem, followed by mature leaves, roots, and flowers. During the growth of cultured cells in suspension, PagDRM1 was highly expressed from the late-exponential phase to the stationary phase. In addition, PagDRM1 expression increased in response to drought, salt stress, and treatment with plant hormones (e.g., abscisic acid and gibberellic acid). Therefore, we suggested that PagDRM1 not only plays an important role in the induction of dormancy, but also contributes to stress tolerance in plants.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.311-343
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• 2004

Various aspect of epidemics broke out continually from the middle of Joseon Dynasty due to the famine and drought caused by abnormal climate of the sixteenth century and the war. Thus the Dynasty performed sacrificial rites, isolated the patients and published plenty of medical books related epidemics in order to cure of the patients, and Heojun edited 『Byeokyeoksinbang』 as 'Dangdokyeok' broke out at Gwanbuk(關北) districts in 1613, Heojun explained the cause of Dangdokyeok as meteorology under the feudal conditions, and concluded Simhwa(心火) by fever toxin, Therefore he selected the method of puting out Simhwa by attack of fever toxin. In addition he presented emergency treatment that can maintain the airway by bleeding. To treat Dangdokyeok, Heojun presented lots of prescriptions so as Seungmagalgeuntang(升麻葛根湯), Cheongyeolhaedoksan(淸熱解毒散), Yeongyopaedok-san(連翹敗毒散), Bangpungtongsaongsan(防風通聖散), Jowiseunggitang(調胃升氣湯) and Hwangryeonhaedoktang(黃連解毒湯) etc. And he proposed Samdueum (三豆飮), Realgar(石雄黃) and so on to prevent infection from that. They presume from 120 to 150 years as the period of human adaptation to the first epidemics. Dangdokyeok put a large number of people to death at first, but it wasn't referred at the history any more after Byeokyeoksinbang. So we can say that the treatment of Heojun may be effective. Common cold and dyspeptic cold broke out in our country differently from 'Shanghan(傷寒)' in the China, so we had settled 'pestilence infectious epidemic disease(瘟疫)' while 'epidemic febrile disease(溫病)' of the China. Dangdokyeok of Heojun is similar to 'Scalet fever' belonging to 'virulent heat pathogen(溫毒)', 'newly epidemic febrile disease(新感溫病)'. As a cure of Dangdokyeok, the Korean medicine uses the treatment of removing fever state whereas the western medicine uses the antibiotics to kill the streptococcus. The symptoms of Dangdokyeok are remarkably similar to those of the Scarlatina, so this occupies a high position on the world history of medicine in aspects of the period and details of symptoms. These days we have the problems that the tolerance of antibiotics increases and disease of unknown cause is prevalent. It means the western medicine get to limits. So if we progress epidemiography based on Heojun's medicine, we may contribute to the world history of medicine.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.7-7
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• 2017

Unfavorable weather and soil conditions reduce rice yield and land and water productivity, aggravating existing encounters of poverty and food insecurity. These conditions are foreseen to worsen with climate change and with the unceasing irrational human practices that progressively debilitate productivity despite global appeals for more food. Our understanding of plant responses to abiotic stresses is advancing and is complex, involving numerous critical processes - each controlled by several genetic factors. Knowledge of the physiological and molecular mechanisms involved in signaling, response and adaptation, and in some cases the genes involved, is advancing. Moreover, the genetic diversity being unveiled within cultivated rice and its wild relatives is providing ample resources for trait and gene discovery, and this is being scouted for rice improvement using modern genomics and molecular tools. Development of stress tolerant varieties is now being fast-tracked through the use of DNA markers and advanced breeding strategies. Large numbers of drought, submergence and salt tolerant varieties were commercialized over recent years in South and Southeast Asia and more recently in Africa. These varieties are making significant changes in less favorable areas, transforming lives of smallholder farmers - progress considered incredulous in the past. The stress tolerant varieties are providing assurance to farmers to invest in better management of their crops and the ability to adjust their cropping systems for even higher productivity and more income, sparking changes analogous to that of the first green revolution, which previously benefited only favorable irrigated and rainfed areas. New breeding tools using markers for multiple stresses made it possible to develop more resilient, higher yielding varieties to replace the aging and obsolete varieties still dominating these areas. Varieties with multiple stress tolerances are now becoming available, providing even better security for farmers and lessening their production risks even in areas affected by complex and overlapping stresses. The progress made in these less favorable areas triggered numerous favorable changes at the national and regional levels in several countries in Asia, including adjusting breeding and dissemination strategies to accelerate outreach and enabling changes at higher policy levels, creating a positive environment for faster progress. Exploiting the potential of these less productive areas for food production is inevitable, to meet the escalating global needs for more food and sustained production systems, at times when national resources are shrinking while demand for food is mounting. However, the success in these areas requires concerted efforts to make use of existing genetic resources for crop improvement and establishing effective evaluation networks, seed production systems, and seed delivery systems to ensure faster outreach and transformation.

• Journal of Environmental Science International
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• v.19 no.9
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• pp.1137-1142
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• 2010

This study proposes a guideline of a green roof system suitable for the local environment by verifying the growth of Zoysia japonica in a shallow, extensive, green roof system under rainfed condition. The experimental soil substrates into which excellent drought tolerance and creeping Z. japonica was planted were made with different soil thicknesses(15cm, 25cm) and soil mixing ratios(SL, $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$, $P_4P_4L_2$). The plant height, green coverage ratio, fresh weight, dry weight and chlorophyll contents of Z. japonica were investigated. For the soil thickness of 15cm, the plant height of Z. japonica was significantly as affected by the soil mixing ratio and it was shown in the order SL= $P_4P_4L_2$ < $P_7P_1L_2$ = $P_5P_3L_2$ < $P_6P_2L_2$. For the soil thickness of 25cm, the plant height was increased in order to SL < $P_7P_1L_2$, $P_6P_2L_2$, $P_5P_3L_2$ < $P_4P_4L_2$. The green coverage ratio was not observed by soil the mixing ratio or soil thickness. However, the green coverage ratio was 86~90% with a good coverage rate overall. The chlorophyll contents of Z. japonica were not significantly affected by the soil mixing ratio in the soil thickness of 15cm, but were higher in the natural soil than in the artificial soil at 25cm soil thickness. The fresh weight and dry weight of Zoysia japonica were heavier in the 25cm thickness than in the 15cm thickness and in the artificial soil mixture than in the natural soil. The result indicated that the growth of Zoysia japonica was more effective in the 25cm soil thickness with artificial soil than in the 15cm soil thickness with natural soil in the green roof system under rainfed condition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.1
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• pp.28-38
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• 2012

This study was conducted to investigate growth performance, photosynthesis, water use efficiency (WUE), and stomatal conductance ($g_s$) of container seedlings of Liriodendron tulipifera and Zelkova serrata growing under three different irrigation periods (1 time/1 day, 1 time/2 days and 1 time/3 days) for high seedling quality. The root collar diameter and height of L. tulipifera and Z. serrata seedlings were highest with 1 time/1 day irrigation, whereas they were lowest with 1 time/3 days irrigation. The two species showed low drought tolerance. As irrigation period was shortened, biomass and seedling quality index (SQI) of the two species increased. The ratio of height to root collar diameter (H/D) and the ratio of below to aboveground biomass (T/R) of the two species were lower with 1 time/3 days than at other irrigation periods. L. tulipifera and Z. serrata seedlings showed significantly higher photosynthetic capacity with 1 time/1 day irrigation. As irrigation period was shortened, $g_s$ of two species increased, while their WUE decreased significantly (P<0.05) These results show that 1 time/1 day irrigation provides the most optimal water condition for container seedling production of two species and irrigation controlling is very important for growth and quality of container seedlings.

• Journal of Climate Change Research
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• v.7 no.1
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• pp.9-17
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• 2016

Climate change affects plant responses on physiological characteristics and growth, and Pinus densiflora, one of the major tree species in Korea, are expected to be particularly vulnerable to rising temperature and increased precipitation. This study was conducted to investigate the effects of an open-field warming and precipitation manipulation on physiological characteristics and growth of P. densiflora seedlings. Seedlings of 2-year-old P. densiflora were planted in April, 2013, in open-field nursery located at Korea University. The air temperature of warmed plots had been set to be $3^{\circ}C$ higher than the control plots using infrared lamps. Precipitation was manipulated to be 30% lower or higher than the control, using transparent panels and drip irrigation. Net photosynthetic rate, total chlorophyll content, seedling height, root collar diameter and biomass were measured from April, 2014 to April, 2015. The increase in new shoot biomass from warming was statistically significant, with the biomass in warmed plots about 2-fold higher than in the control plots in 2014 and 2015. This result might be related to advanced bud burst and increased occurrence of abnormal new shoots in warmed plots. Meanwhile, the results of net photosynthetic rate, total chlorophyll content, seedling height, root collar diameter and total biomass from warming and precipitation manipulation were not statistically significant, but tendencies of lower net photosynthetic rate and higher seedling height and biomass in warmed plots compared to the control were shown. Such might be speculated as results of the extended growth period. When root to shoot (R/S) ratio was calculated from the biomass data obtained in April 2014 and April 2015, increased R/S ratio was observed regardless of the treatments applied. Drought tolerance of P. densiflora and particularly low annual precipitation observed in 2014 were suggested as the possible reasons.