• Plant Disease and Agriculture
• /
• v.5 no.2
• /
• pp.77-83
• /
• 1999

In 1997 surveys 82 out of 180 crucifer fields were infected with clubroot disease in a range of 1-100% of diseased plants and among crucifier crops Chinese cabbage was the most severe, In cropping systems Chinese cabbage-monocropping of Chinese cabbage-radish were found to be most common in major Chinese cabbage production areas. Welsh onion squash or paddy rice were also planted between cropping of Chinese cabbage. Paddy fields converted to upland were lowered in incidence of clubroot disease and fields with loam to silty loam soil were more severe in disease than those with sandy soil. Soil pH and organic contents were nor related to clubroot disease severity. Soil fauua such as total fungi bacteria actinomyces Pseudomonads and Bascillus were not correlated with severity of the disease. Root rall development on Chinese cabbage seedlings was initifially observed under a microscope 13 days after inoculation with Plasmodiophora brassicae but 18 days by naked eyes after inoculation. Root galls were formed mostly around collar roots and gradually spread to main root lateral roots and secondary root branches. Root galls started to enlarge greatly in size and weight from 23 days after inoculation. Chinese cabbage plants at mid-growth stage with root gall development were reduced to 1/2 of that of healthy plants in number of leaves 1/4-1/5 in above ground fresh weight 1/6 in root length but increased to 3 times in diameter of collar root. Diseased plants had little root hairs. Diseased Chinese cabbage plants at harvest were reduced by 9,1-11.8% in head weight compared to healthy plants a positive correlation was observed between root and head weight but those relationships were rot found in the diseased plants.

• Korean journal of applied entomology
• /
• v.22 no.3 s.56
• /
• pp.181-185
• /
• 1983

Ditylenchus destructor Thorne 1945 was found to be the causal organism of the new root rot disease of Panax ginseng, which occurred extensively in Dongseong area of Cheolweon-gun, Gangweon Province, Korea in 1982. Thirty-six percent of the investigated fields was damaged due to the potato rot nematode. Infected roots showed brown discoloration of cortex and suberization outside the cambium. Cortex of the severly infected roots became sponge-like in texture and cavity was produced in the central portion of the root. Only the severely infected ginseng plants exhibited sympotoms of sudden wilting of leaves. The number of potato rot nematode in such field soils was $8.5\~222/30g$ soil, while there was no such symptoms on leaves if the number was less than 7.

• Journal of Korean Society of Forest Science
• /
• v.48 no.1
• /
• pp.59-63
• /
• 1980

The resistance to water transport were measured for the species which are easy for rooting and the species which are difficult for rooting from cutting to rooting. The experimental materials were selected as Euonymus japonica and Viburnum Awabuki for the species easy to root and Quercus glauca, Pasania edulis and Rhaphiolepsis umbellata var. integerreima for the species that are difficult to root. The results were summarized as follows; 1. As the time passed after cutting, the variation of total resistance (RT) showed a slow increase for the species easy to root, while the species that were difficult to root showed a rapid increase. 2. The stem resistance without leaves (RS) showed a rapid increase for the species easy to root but the species difficult to root had nearly constant values. 3. The stem resistance in the cross section (RC) increased noticably for the species difficult to root showed no increase. Furthermore the stem resistance in the cross section (RC) depended on the variation of the stem resistance without leaves (RS). 4. The total resistance (RT) consisted mainly of the resistance of the axil part (RL) for the species difficult to root.

• Korean Journal of Medicinal Crop Science
• /
• v.16 no.2
• /
• pp.79-85
• /
• 2008

Some studies of dandelion have been carried out on bioactivities, however, no comparative analysis on antioxidant and cytotoxic activities in the Korean dandelion (T. coreanum NAKAI.; KD) and dandelion (T. officinale WEB.) have been reported. In this study, the extracts of KD and dandelion analyzed relative phenolic contents and free radical scavenging, antioxidant enzyme and cytotoxic activities. The extract of Korean dandelion leaves (KDL) exhibited a higher phenolics content ($368{\pm}11.5\;mg/l00\;g$) and a strong free radical scavenging activity ($RC_{50}$value;87.89 ug/ml) than other parts and BHT (120.12 ug/ml), synthetic antioxidant. At ascorbate peroxidase (APX) activity, the dandelion root (DR) had a greater (38.8 U/mg protein) antioxidant enzyme compare to the dandelion leaves (12.2 U/mg protein). The catalase (CAT) and superoxide dismutase (SOD) followed higher enzyme activity in Korean dandelion root (KDR) than other parts. In a cytotoxic activity against human cancer cell, the extracts of KDR was found to be active against Calu-6, HCT-116, and SNU-601 cell lines, with $IC_{50}$ values of 522.34, 532.74 and 614.85 ug/ml, respectively. These results suggest that KD and dandelion would be an alternative antioxidant source, based on natural plant resources.

• Proceedings of the Ginseng society Conference
• /
• 1978.09a
• /
• pp.55-66
• /
• 1978

Five ginsenosides $(A_1,\;A_2,\;B_1,\;B_2,\;C)$ and a yellow pigment were isolated from American ginseng stems and leaves. Ginsenoside $A_2,\;B_1,\;B_2$ and C were proven to be identical with Korean ginseng root ginsenoside $Rg_1,$ Rd, Re and $Rb_2,$ respectively. The yellow pigment proved identical with panasenoside isolated from Korean ginseng leaves. Ginsenoside $A_1$, which was also present in American ginseng roots, was not identical to any of the known root (ginsenoside $R_{0}-Rg_{2}$) and leaf (ginsenoside $F_{1}-F_{3}$) Korean ginseng saponins. A gas-liquid chromatographic method was developed to analyze ginsenosides and sapogenins in rabbit plasma and urine samples. Panasenoside and stigmasterol were found to be the best internal standards for ginsenosides and sapogenihs, respectively. Ginsenoside C had a significantly longer half-life, higher plasma protein binding, lower metabolic and renal clearance than ginsenoside $A_1,\;A_2\;and\;B_2$. Ginsenosides were not found in rabbit plasma and urine samples after oral administration. Ginsenoside C had a higher toxicity than ginsenoside $A_2$ after intraperitoneal administration to mice. Toxicity was not observed after oral administration of the ginsenosides.

• Korean Journal of Organic Agriculture
• /
• v.6 no.1
• /
• pp.151-160
• /
• 1997

Azospirillum sp., photosynthetic bacteria(Rhodopseudomonas sp.) and Pseudomonas sp. were separated and screened from soil and soilless culture, and identificated. The antifungal activities against root-infected pathogens and plant growth promoting effects of the cultured solution of the starins(5.0$\times$105 cells/$m\ell$) in the peatmoss compost on the early growth of cucumber and tomato seedling were investigated. Azospirillum sp. and Pseudomonas sp. showed a antifungal activities against Fusarium sp., Pythium sp. and Rhizoctonia sp in thed ranges of 51.0% to 72.0% on potato dextrose agar medium, however photosynthetic bacteria had not antifungal activities. When cultured solution of Azospirillum sp., photosynthetic bacterial and Pseudomonas sp. were bacterialized by mixing with peatmoss compost, early growth of cucumber and tomato in terms of plant height, number of leaves, leaf area, root length, fresh anf dry weight of leaf, stem and root were promoted, especially photosynthetic bacteria had a the best plant growth promting activities.

• Plant Biotechnology Reports
• /
• v.5 no.4
• /
• pp.309-315
• /
• 2011

Rice grown in anaerobic waterlogged soil accumulates ammonium as a major source of nitrogen (N). We have compared the physiological symptoms of rice seedlings subjected to N-starvation stress with those receiving sufficient N, based on measurements of shoot/root length and weight and an analysis of protein expression patterns. N starvation marginally increased root growth but notably decreased shoot biomass. N uptake was reduced by >50% in the roots and shoots of N-starved seedlings. To better understand the mechanism of N starvation in rice, we performed a comparative proteome analysis of proteins isolated from rice leaves. Twenty-five differentially expressed proteins were analyzed by matrixassisted laser desorption/ionization time-of-flight (TOF) mass spectrometry and electron spray ionization quadrupole TOF. Functional analysis of the N-starvation response proteins suggested their involvement in protein synthesis and fate, metabolism, and defense. These results indicate that these proteins may play important roles in regulating the plant's complex adaptation responses for N use during N starvation. The proteins may be useful for further characterization of protein function in plant N nutrition.

• Journal of Plant Biology
• /
• v.14 no.4
• /
• pp.5-13
• /
• 1971

Pot and paddy field tests were conducted to study red discoloration of rice var. IR 667 leaves with reference to the leading Korean native variety Jinhung and Paldal, with the following results: 1. Minor elements such as Mn, Fe, B, Al, Ca and Si had no influence on the discoloration, but a supply of various soluble nitrogen compounds completely restricted it. The more prosperous the growth of IR 667 with nitrogen, the more severe the discoloration appears when nitrogen absorptin becomes limited. 2. Chlorotic pigments extracted from both IR 667 and Jinhung were compared spectrophotometrically, and found to have different spectral peaks. IR 667 had peak closer to red than Jinhung, indicating the characteristic of the variety. IR 667 was observed to be more sensitive to nitrogen deficiency than Jinhung or the other japonica variety. 3. It was concluded that all the factors limiting nitrogen supply for IR 667 growth, such as low nitrogen application, restriction of root respiration (low temperature, poor drainage, toxic gases or substances in the root zone, etc.) and pest injuries, would result in the appearance of the so-called red discoloration, because of the reduction in nitrogen uptake. Since, the discoloration of IR 667 is varietal characteristic when grown in Korea, control of it may be beneficial cultural practice in increasing grain yield, although the increased succeptibility to pests and a drop in the rate of maturity due to relatively high nitrogen level in the leaves may result in an unexpected drop in yield. It is anticipated that further exploration conducted from practical point of view will establish the relatioknships between the extent of red discoloration, nitrogen availability and grain yield in IR 667.

• Food Science and Biotechnology
• /
• v.14 no.2
• /
• pp.177-180
• /
• 2005

Antioxidant activity of crude extracts from colored sweet potato cultivars by plant parts such as root, stem and leaf was evaluated. The highest TBARS values were obtained from root samples of sweet patato, and followed by stems and leaves, indicating that leaf sample showed the strongest antioxidant activity. Sweet potato cultivars with yellow flesh and leaf part exhibited strong antioxidant activities. Antioxidant activities of leaf and stem extracts were maintained for 21 days and were a little lower than that of BHT. The DPPH radical scavenging activity was the highest in "Sinhwangmi" leaf, and followed by "Jami" root. Chlorogenic acid was detected as the most abundant antioxidant substance among all fractions. These results suggest that the antioxidant activity of sweet potato differs depending on plant part and cultivar.

• Korean Journal of Veterinary Service
• /
• v.36 no.4
• /
• pp.227-232
• /
• 2013

The dried root of Angelica gigas (A. gigas) has been traditionally used as an oriental medicine, which is known to improve blood circulation and blood stasis. In the present study, leaves and stalks of A. gigas were used to investigate their effects on the innate immunity. The extracts were prepared from leaves and stalks of A. gigas and were fed to mice. The numbers of blood cells, total WBCs, neutrophils, lymphocytes, eosinophils and basophils were increased by 50% in mice fed with leaves extract of A. gigas compared to control mice. However, the numbers of blood cells were decreased when treated with stalks extract of A. gigas. The level of cholesterol and triglyceride in serum was markedly reduced in both mice group fed with leaves extract and stalks extract of A. gigas compared to control group (P<0.01). There was no significant change in the level of albumin, total protein, phosphate and calcium in serum. Activity of cationic peptide was found to be diffused in the testicles of mice fed with leaves extract of A. gigas compared to control group, which might be due to increased lysozyme in testicle. The lysoplate assay and immunohistochemistry assay suggest that the extract of leaves and stalks of A. gigas are immunogenic, but the effects might be related with acquired immune response rather than innate immunity.