• 한국작물학회지
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• 제44권4호
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• pp.309-315
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• 1999

Rice seedling test was conducted to check the loging tolerance at ripening stage through evaluating the root characters. Thirteen Korean and foreign rice cultivars with direct seeding adaptable or high quality characteristics were grown in a cell pot and under submerged paddy. The root characters and pushing resistance of rice hill were determined at seedling and ripening stage, respectively. The diameter of crown root at the 7th and 8th leaf stages was thicker in lodging tolerance cultivars than those of others and showed significant-positive correlation with both pushing resistance and crown root diameter of mature plants. Also, the tensile strength of crown root at the 7th and 8th leaf stage showed highly positive correlation with the tensile strength of crown root of mature plants. The number of crown root at 7th leaf stage was significant-positively correlated with that of mature plant. The diameter of seminal root was not significantly correlated with the diameter of crown root throughout the whole growth stage. These results indicate that the diameter, tensile strength and number of crown root associated with root lodging tolerance can be detected with the seedling at about 7th or 8th leaf stage, and the seedling test using the cell pot is an useful and practical method to select lodging tolerant cultivars or lines of rice based on root characters, especially diameter of crown root.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.328-328
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• 2017

Drought is a major limiting factor that reduces rice production and occurs often especially under recent climate change. Plants have the ability to alter their developmental morphology in response to changing environment, which is known as phenotypic plasticity. In our previous studies, we found that one chromosome segment substitution line (CSSL50 derived from Nipponbare and Kasalath crosses) showed no differences in shoot and root growth as compared with the recurrent genotype, Nipponbare under non-stress condition but showed greater growth responses compared with Nipponbare under mild drought stress condition. We hypothesized that reducing root respiration as metabolic cost, which may be largely a consequence of aerenchyma formation would be one of the key mechanisms for root plasticity expression. This study aimed to evaluate the root respiration and aerenchyma formation under various soil moisture conditions among genotypes with different root plasticity. CSSL50 together with Nipponbare and Kasalath were grown under waterlogged conditions (Control) and mild drought stress conditions (20% of soil moisture content) in a plastic pot ($11cm{\times}14cm$, ${\varphi}{\times}H$) and PVC tube ($3cm{\times}30cm$, ${\varphi}{\times}H$). Root respiration rate was measured with infrared gas analyzer (IRGA, GMP343, Vaisala, Finland) with a closed static chamber system. There was no significant difference between genotypes in control for shoot and root growth as well as root respiration rate. In contrast, all the genotypes increased their root respiration rates in response to mild drought stress. However, CSSL50 showed lower root respiration rate than Nipponbare, which was associated by higher root aerenchyma formation that was estimated based on internal gas space (porosity) under mild drought stress conditions. Furthermore, there were significant negative correlations between root length and root respiration rate. These results imply that reducing the metabolic cost (= root respiration rate) is a key mechanism for root plasticity expression, which CSSL50 showed under mild drought.

• Journal of applied mathematics & informatics
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• 제28권1_2호
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• pp.373-381
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• 2010

In this paper we determine all elements in the root lattice of symmetrizable generalized Kac-Moody algebras whose reflections preserve the root systems. Also we discuss elements in the root lattices whose reflection preserve the root lattices.

• Journal of Ginseng Research
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• 제11권1호
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• pp.10-16
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• 1987

인삼제품의 품질관리와 효능연구의 시료사용에 참고자료로 활용하기 위하여 인삼근의 부위별, 연근별 사포닌 함량 및 분포를 조사하였다. 한국인삼 6년근의 부위별 조성은 뇌두(rhizome) 4.1%, 동체(main root) 47.7%, 지근(lateral)의 비는 대략 1:1이었으나 지근부는 2:1로 피층이 많았다. 사포닌분포는 동체와 세근부가 29% 정도로 거의 같고, 지근부 34.6%로 가장 많았고, 뇌두는 7% 수준으로 가장 적었다. 그러나 단위 중량당 함량에서는 세근>퇴두>지근>동체의 순으로 뇌두가 높은 반면 동체는 가장 낮았다. 연근별 사포닌 변화는 2년근 4.89%, 6년근 7.98%로서 본포이식후 4년간 약 3% 증가에 그쳤으나 뿌리의 비대성장을 고려할 때 계속적으로 합성축적 되었으며 연간 증가율은 5년근이 43.8%로 가장 왕성한 성장기임을 나타내고 4년근 19.8%, 6년근 21.1%로 비슷했다. 따라서 5년에 뿌리의 생장과 사포닌 합성축적이 최고 수준에 도달했다가 6년째 부터 쇠퇴기로 됨을 알았다. 개별 사포닌의 함량변화는 전반적으로 증가하는 경향이나 PT계 사포닌보다는 PD계 사포닌의 증가가 보다 큰 경향이었다.

• 한국약용작물학회지
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• 제21권3호
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• pp.184-190
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• 2013

This study was carried out to investigate ginsenoside content in different root parts and the correlation between root diameter and ginsenoside composition of Panax ginseng C. A. Meyer cultivated by direct seeding. The unit contents of ginsenoside were 29.65, 28.76, 26.34 mg/g, respectively in 4, 5, 6 years old. However, the total contents of ginsenoside were 431.97, 606.56, 657.80 mg/root, respectively. Total ginsenoside content of fine root was higher than that of main root and lateral root. These tendencies were related to decrease by the increase of root diameter. When diameter of main root and lateral root were the same in different ages, the total ginsenoside content was higher in the order of 4 > 5 > 6 years old roots. Except for ginsenoside-Rg1, other ginsenosides components (PD/PT and total ginsenosides) had highly negative correlation with the root diameter within whole root, main root, lateral root and fine root, which indicated that ginsenoside content is correlated to root diameter. As results, it is suggested that ginsenoside content can be predicted.

• Journal of Ecology and Environment
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• 제42권4호
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• pp.155-162
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• 2018

Background: In ecosystem carbon cycle studies, distinguishing between $CO_2$ emitted by roots and by microbes remains very difficult because it is mixed before being released into the atmosphere. Currently, no method for quantifying root and microbial respiration is effective. Therefore, this study investigated the relationship between soil respiration and underground root biomass at varying distances from the tree and tested possibilities for measuring root and microbial respiration. Methods: Soil respiration was measured by the closed chamber method, in which acrylic collars were placed at regular intervals from the tree base. Measurements were made irregularly during one season, including high temperatures in summer and low temperatures in autumn; the soil's temperature and moisture content were also collected. After measurements, roots of each plot were collected, and their dry matter biomass measured to analyze relationships between root biomass and soil respiration. Results: Apart from root biomass, which affects soil's temperature and moisture, no other factors affecting soil respiration showed significant differences between measuring points. At each point, soil respiration showed clear seasonal variations and high exponential correlation with increasing soil temperatures. The root biomass decreased exponentially with increasing distance from the tree. The rate of soil respiration was also highly correlated exponentially with root biomass. Based on these results, the average rate of root respiration in the soil was estimated to be 34.4% (26.6~43.1%). Conclusions: In this study, attempts were made to differentiate the root respiration rate by analyzing the distribution of root biomass and resulting changes in soil respiration. As distance from the tree increased, root biomass and soil respiration values were shown to strongly decrease exponentially. Root biomass increased logarithmically with increases in soil respiration. In addition, soil respiration and underground root biomass were logarithmically related; the calculated root-breathing rate was around 44%. This study method is applicable for determining root and microbial respiration in forest ecosystem carbon cycle research. However, more data should be collected on the distribution of root biomass and the correlated soil respiration.

• Journal of Ginseng Research
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• 제9권1호
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• pp.24-35
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• 1985

Rusty root of ginseng has been known as one of the limiting factors in ginseng production in Korea. An attempt was, therefore, made to elucidate biological and chemical natures of the rusty root, and the redox Potential of the ginseng cultivated soils were measured and compared with diseased and non-diseased soils. Reddish discoloration was most frequently observed on the epidermis of ginseng root and the pigments were accumulated in all epidermal cells of the diseased lesions. The lower the redox potential of the ginseng cultivated soil was, the more severe the rusty root was observed. Fe content in the diseased epidermis was 3 times higher than that of healthy one. Organic acids such as oxalic, malonic, succinic, and citric acids were also higher in the mss root than in the healthy one. Thin layer chromatogram of phenolic acid fractions obtained from the epidermal cells of the rusty root of ginseng exhibited 3 to 4 unidentified substances not found in the healthy root. Also lignification of the epidermal cells and the activity of phenylalanine ammonia lyase were greater in the rusty root than the healthy root. Colony formation and conidia production of F. solani, And mycelial growth and sclerotium formation of Sclerotinia sp. isolated from ginseng root were suppressed in a nutritionally minimal medium supplemented with water extract of rusty ginseng root epidermis. It is, therefore, suggested that rusty root of ginseng is caused by unfavorable rhizosphere environmental stress or stresses resulting abnormal metabolism in the root as a selfdefence mechanism of non-specific resistance responses.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2002년도 생물공학의 동향 (X)
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• pp.305-308
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• 2002

접종 초기 root segmentation 은 뿌리의 생장 속도를 감소시키고 그 생산성을 저하시키기도 하지만 F/D ratio를 감소시켜 뿌리가 자랄 수 있는 배지 내 공간을 제공하기 때문에 고농도 배양에 유리할 뿐 아니라, 생산성이 높은 secondary root의 비율을 증가시키기 때문에 decursinol angelate 의 생산량을 중대시킨다. 참당귀 뿌리배양을 위한 plant growth regulator의 최적 조건으로 secondary root의 생장성 측면이나 decursinol angelate 의 생산성 측면에서 4 mg/L 이상의 IBA 첨가가 요구됨을 확인하였다.

• 한국작물학회지
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• 제43권3호
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• pp.161-167
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• 1998

Root and shoot development of two rice (Oryza sativa L.) cultivars with different genetic backgrounds was studied with reference to their relative growth. Tongil type (indica-japonica hybrid) cultivar 'Kuemkangbyeo' and japonica cultivar 'Koshihikari' were grown in $5000^{-1}$ a Wagnar pots under flooded condition. Three plants with roots of both cultivars were taken in every phyllochron through the heading stage to record morphological characteristics of shoot and root system. Compared to Koshihikari, Kuemkangbyeo produced more tillers and had greater shoot weight and leaf area per hill. Length and weight of the root system in both cultivars increased exponentially with time. At the same time, root system development was significantly faster in Kuemkangbyeo than in Koshihikari after the panicle initiation stage. As a result, Kuemkangbyeo has a vigorous root system which consists of larger number of nodal roots compared to Koshihikari. Also, the root length and weight per unit leaf area of Kuemkangbyeo were larger than those of Koshihikari in the later half of growing period, which suggests possible higher physiological activity of the root system of Kuemkangbyeo which is known as a high-yielding cultivar. The relationship between root traits (crown root number, total root length, and root dry weight) and shoot traits (leaf area and leaf+culm dry weight) in both cultivars closely showed allometry until the flag leaf stage.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2014년도 춘계 학술논문 발표대회
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• pp.230-231
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• 2014

This study is concerned with the root penetration resistance competence and constructability of a waterproofing and root penetration resistance layer of an eco-bridge which is applied with various types of seeding. For the review of root penetration resistance competence, the competence was tested using herbs, woody plants, and tall trees. As a result, there was no tear of or damage to the waterproofing and root penetration resistance layer as well as the sweeping-down phenomenon of a waterproofing and root penetration resistance layer by soil. Also, the effect of the root growth of herbs, woody plants, and tall trees on the root penetration resistance system was confirmed.