• Korean Journal of Plant Resources
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• v.7 no.1
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• pp.13-15
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• 1994

Some known coumarins, decursin, nodakenetin, umbelliferone, 7-demethylsuberosin, columbianetin, decursinol angelate and decursinol, showing significant cytotoxic activities against P388 cell lines,were isolated from the roots of Angelica gigas (Umbelliferae) . 7-Demethylsuberosin and columbianetinwere obtained from Angelica gigas for the first time. Chernotaxonornic difference about coumarins com-ponents between the roots of Angelica gigas and those of A. acutiloba is also discussed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.336-339
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• 2005

Common thistle contains water-soluble substances that are antioxidative to foods. Antioxidant activities measured by DPPH method for the ground samples were the greatest in leaves, although was less than that of commonly used antioxidants, BHT and ascorbic acid. Methanol extracts and fractions from Xanthium occidentale plants dose-dependently increased DPPH free radical scavenging activity, in vitro test. The extracts from leaves showed the strongest antioxidant activity. DPPH scavenging activity of the individual fraction was in order of n-butanol>water>ethyl acetate>n-hexane fraction. By means of HPLC analysis, leaf samples of Xanthium occidentale had the highest amount of phenolic compounds, related with antioxidant activity, and followed by stems and roots. Total content of these antioxidant phenolic com­pounds for leaves extracts were detected in water fraction (36.7 mg 100 $g^{-1}$) as the greatest amount, especially chlorogenic acid (39.4 mg 100 $g^{-1}$) was the greatest component. These results suggest that Xanthium occidentale plants had potent antioxidant activity, and their activities were differently exhibited depending on plant part and fraction.

• Journal of Biosystems Engineering
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• v.22 no.4
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• pp.479-486
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• 1997

식물 뿌리에 대한 지식은 식물-토양 사이의 관계 이해, 토양의 호율적 관리, 식물에 의한 영양분과 수분의 흡수 과정 이해, 그리고 토양 등급 지수를 만드는데 있어서 아주 중요하다 식물 뿌리에 관한 정보를 정량화하기 위하여는 뿌리를 흙으로부터 씻어내고 뿌리의 길이, 표면적, 중량과 같은 식물 뿌리의 특성을 측정하여야 한다 하지만 이렇게 뿌리를 씻어 낸 다음 뿌리의 특성을 측정하는 기존의 방법을 이용할 경우 막대한 시간과 노동력이 필요하여 뿌리에 관한 많은 양의 정보를 얻는데 큰 어려움이 있다. 이 연구에서는 식물 뿌리를 관측하는데 필요한 시간과 노동력을 줄일 수 있는 식물 뿌리 측정법을 세선 작업과 자외선 명암 증진법을 이용한 영상 정보 처리 장치를 바탕으로 하여 개발하였다. 개발된 화상 정보 처리 장치를 이용하여 옥수수 뿌리의 길이를 재었을 때 기존의 뿌리 길이 측정 방법보다 2.5 배 발리 측정할 수 있는 것으로 나타났다.

• Korean journal of applied entomology
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• v.3
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• pp.21-25
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• 1964

1. Purpose of this experiment is to investigate the influence of wheat scab fungus(Gibberella zeae) remaining in soil or residues of infected plants to the growth of the seedlings of 14 different crops. 2. Susceptibility of these crops to the infection by G. zeae was investigated by planting these crops both to the artificially inoculated soils and naturally infected soils where both serious and light wheat scab epidemic have occurred previously. 3. In artifical inoculation tests, bailey, wheat, rye, soybean, rice, buckwheat, corn, cotton and greenbean has shown susceptible reaction, while indianbean, sesame, sorghum, chinese cabbage and radish has shown resistant reaction. 4. In artificial inoculation tests, there was significant difference in the germination ratio of the susceptible crops between the plants planted in inoculated soils and uninoculated soils with the exception of rice, com and cotton. Preemergence seedling blight was confined only to barley and corn, whereas postemergence seedling blight was confined to rye, wheat, rice buckwheat, barley and corn. la most of the susceptible crops secondary roots were almost rotted and the primary roots were either partially rotted or discolorated in inoculated soil. There was significant difference in the stem length of the plants grown in inoculated soils and uninoculated soils in susceptible crops. 5. No infection by G. zeae was observed when wheat, barley and rye plants were sown to the soils where both serious and light wheat scab epidemic occurred naturally.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.5
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• pp.402-406
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• 2003

Greenhouse and laboratory studies were conducted to determine the allelopathic potentials of extracts or residues from sweet potato (Ipomoea batatas L. (Lam). The extracts applied on filter paper in a Petri dish bioassay significantly inhibited root growth of alfalfa. Aqueous leachates at 40g dry tissue $\textrm{L}^{-1}$ (g $\textrm{L}^{-1}$) from leaves showed the highest inhibition against alfalfa, and followed by stems and roots. Alfalfa root growth was significantly inhibited by methanol extracts of the same plants as the concentration increased. The effect of residue incorporation into soil on seedling growth of com, soybean, barnyard grass and eclipta was examined in the greenhouse, and results showed that the leaf residues at 200g $\textrm{kg}^{-1}$ by plant parts inhibited shoot dry and root dry weights of test plants by 60-80%. By means of HPLC, causative allelopathic substances present in plant parts of sweet potato "Sinyulmi" were identified as coumarin, trans-cinnamic acid, o-coumaric acid, p-coumaric acid, and chlorogenic acid. Total content of these compounds for leaves extracts were detected as the greatest amount in EtOAc fraction, especially trans-cinnamic acid was the greatest component. These results suggest that sweet potato plants have herbicidal potentials, and that their activities exhibit differently depending on plant parts.ant parts.

• Journal of Periodontal and Implant Science
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• v.23 no.1
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• pp.159-169
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• 1993

The thirty six mandibular second molars, which were extracted because of hopeless tooth due to advanced periodontal disease, were measured the length of mesial and distal root and the distance from cementoenamel junction to root separation. The molars were cross-sectioned every 1.5 milimeter from cementoenamel junction to root apex perpendicular to long axis and each section was photographed, projected and measured with a calibrated Digital Curvi-Meter(Com Curvi-8. Japan). The root surface area (RSA), percentage of the RSA and the linear variation of the RSA were calibrated for each 1. 5 mm section. The results were as follows. 1. The mean length of the roots was 12. 98mm for mesial root, 11.84 mm for distal root. The mesial root was longer than distal root.(p<0.01) 2. The mean distance from the cementoenamel junction to the point at which the root separate from the root trunk was 3.82mm for the buccal furcation and 4.75mm for lingual furcation. The buccal root separation was coronal than the lingual root separation.(p<0.01) 3. The total root surface area was $317.78mm^2$. 4. The mean surface area of the root trunk was $150.06mm^2$ and averaged 42.54% of the total root surface area. 5. The mean root surface area was $88.79\;mm^2$ for the mesial root, $78.93mm^2$ for distal root, The mesial root surface area was wider than the distal root surface area.(p<0.05) 6. In comparision, the mean root trunk surface area of the mandibular 2nd molar was wider than that of mandibular 1st molar(p<0.01), but each root of 2nd molar was smaller than that of 1st molar(p<0.01).

• Korean Journal of Plant Tissue Culture
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• v.27 no.1
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• pp.63-69
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• 2000

In order to establish a micropropagation system for buffalo gourd (Cucurbita foetidissima ) and common milkweed (Asclepias syriaca), the effects of several plant growth regulators and culture temperature on shoot multiplication and rooting were investigated. In buffalo gourd, the greatest number of shoot from shoot tip culture and well growth of formed shoot were obtained on the MIS medium supplemented with 1.0 mg/L BA and 0.3 or 0.6 mg/L IAA. Whereas kinetin and 2iP were not effective for shoot multiplication in vitro. It was found that 22$^{\circ}C$ and $25^{\circ}C$ were suitable for shoot multiplication. Roots were easily formed by the addition of auxins, especially 1.0 or 2.0 mg/L IBA and 2.0 mg/L IAA. Over 90% of plants survived successfully after being transferred into the field. In common milkweed, BA was more effective than kinetin or 2iP for its micropropagation in vitro. The increased shoot weight and number of nodes per shoot were obtained on the medium containing 3.0 mg/L BA and 0.3 or 0.6 mg/L IAA. But 2iP promoted the shoot elongation. In addition. common milkweed was sensitive to culture temperature in vitro. Temperature around 22$^{\circ}C$ was favorable for shoot multiplication and growth, whereas temperature higher than $25^{\circ}C$ usually reduced the rate of shoot survival rate.