• The Plant Pathology Journal
• /
• v.23 no.3
• /
• pp.223-225
• /
• 2007

Many plant growth-promoting rhizobacteria (PGPRs) have been known for beneficial effects on plants including biological control of soilborne pathogens, induced systemic resistance to plant pathogens, phytohormone production, and improvement of nutrient and water uptake of plants. We developed a simple and rapid method for screening potential PGPR, especially phytohormone producing rhizobacteria, or for analyzing their functions in plant growth using cucumber seedling cuttings. Surface-sterilized cucumber seeds were grown in a plastic pot containing steamed vermiculite. After 7 days of cultivation, the upper part 2 cm in length of cucumber seedling, was cut and used as cucumber cuttings. The base of cutting stem was then dipped in a microcentrifuge tube containing 1.5ml of a bacterial suspension and incubated at $25^{\circ}C$ with a fluorescent light for 10 days. Number and length of developed adventitious roots from cucumber cuttings were examined. The seedling cuttings showed various responses to the isolates tested. Some isolates resulted in withering at the day of examination or in reduced number of roots developed. Several isolates stimulated initial development of adventitious roots showing more adventitious root hair number than that of untreated cuttings, while some isolate had more adventitious root hair number and longer adventitious roots than that of untreated control. Similar results were obtained from the trial with rose cuttings. Our results suggest that this bioassay method may provide a useful way for differentiating PGPR's functions involved in the development of root system.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.6 no.2
• /
• pp.78-88
• /
• 2003

This study was conducted to develop the plant-mat for ecological restoration which was formed as the thin multi-layers of woven nets, soil media, seeds, etc. The experimental site was selected at a slope of 240$m^2$ at the rear of Design College of Sangmyung University and divided into 8 sub-experimental plots (20$m^2$ each) according to mat types. (forest-type and grass-type mats with and without seed attachment, respectively) Also, the existing vegetation plot and the no-treatment plot were included in this experiment for comparison. The experiment construction was conducted on September 3, 2002. Mat covered plots regardless of seed attachment showed nearly no signs of erosion even if rainy season in summer compared to the no-treatment plot. Vegetation monitoring result showed that germination rates were somewhat high in both forest and grass-type mats without seed attachment in the initial germination stage. Although germination rates of seed attached mats were somewhat slower than non-seed attached mats in the germination stage, but over time, it showed a good rooting and shooting environment for germinated tree and grass species because of soil media existence within the mat. This indicates that while non seed-attached mats require follow-up maintenance, seed-attached mats does not require maintenance after rooting and germination.

• Korean Journal of Organic Agriculture
• /
• v.20 no.4
• /
• pp.475-490
• /
• 2012

Since 1997, Korean Ministry of Knowledge Economy and Ministry of Environment have established data on some 400 basic raw and subsidiary materials and process like energy, petro-chemical, steel, cement, glass, paper, construction materials, transportation, recycling and disposal etc by initiating establishment of LCI database. Regarding agriculture, Rural Development Administration has conducted establishment of LCI database for major farm products like rice, barley, beans, cabbage and radish etc from 2009, and released that they would establish LCI database for 50 items until 2020 later on. The domestic LCI database for seeds, seedling, agrochemical, inorganic, fertilizer and organic fertilizer etc is only at initial stage of establishment, so overseas LCI databases are brought and being used. However, since the domestic and overseas natural environments differ, they fall behind in reliability. Therefore, this study has the purpose to select organic farming materials, survey the production process for various types of organic farming materials and establish LCI database for the effects of greenhouse gas emitted by each crop during the process. As for selecting methods, in this study organic farming materials were selected in the method of direct observation of material and bottom-up method a survey method with focus on the organic farming materials admitted into rice production. For the basic unit of carbon emission amount by the production of 1kg of organic farming material, the software PASS 4.1.1 developed by Korea Accreditation Board under Ministry of Knowledge Economy was used. The study had the goal to ultimately provide basic unit to calculate carbon emission amount in executing many institutions like goal management system and carbon performance display system etc in agricultural sector to be conducted later on. As a result, emission basic units per 1kg of production were calculated to be 0.04968kg-$CO_2$ for oystershells, 0.004692kg-$CO_2$ for expanded rice hull, and 1.029kg-$CO_2$ for bordeaux mixture liquid.

• The Korean Journal of Mycology
• /
• v.40 no.4
• /
• pp.258-265
• /
• 2012

Bacterial strains isolated from diseased red pepper fruits showed inhibitory effect on mycelial growth and spore germination of Colletotrichum gloeosporioides. The bacterium was identified as Paenibacillus sp. based on its physiological, biochemical characteristics and MicroLog analysis and named Paenibacillus sp. IUB225-08. The bacterium showed the highest level of antifungal activity C. gloeosporioides when cultured at $25^{\circ}C$ for 60 hrs in LB broth with initial pH of 7.0. The butanol fraction from culture extract of Paenibacillus sp. IUB225-08 effectively inhibited the mycelial growth and spore germination of C. gloeosporioides than any other agricultural chemicals tested. Pepper fruits and seeds treated with spores of C. gloeosporioides showed symptoms, while those treated with the culture extract and C. gloeosporioides together did not show any symptoms. Therefore, the culture extract of Paenibacillus sp. IUB225-08 have a potential for biocontrol agent of red pepper anthracnose.

• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.3
• /
• pp.200-208
• /
• 1999

In this paper, the corona discharge is analyzed by Finite Element Method(FEM) combined with Flux-corrected Transport(FCT) algorithm. In the previous papers, Finite Difference Method(FDM) combined with FCT was used. Usually in the FDM, the regionof interest is discretized with structured grids. But to refine local regions with same resolution, much more grids are required for the structured grids than for unstructured grids than for unstructured grids. Therefore, we propose the FEM-FCT method to simulate the corona discharge. The proposed method has good flexibility in model shape and can reduce the computational cost by the local refinement where the physical quantities have steep gradients. Using the proposed method, we study the streamer growth of parallel plate electrodes which is initiated by the low and high perturbation density. We find that the varying the initial density of perturbation has very little effect on the streamer propagation. And the corona discharge of the rod-to-plane electrode is simulated. On the surface of the rod electrode, the high concentration of the electric field gives rise to many number of streamer seeds. The strong axial streamer propagate to the plane electrode. The weaker non-axial streamer repel each other and stop growing more. The results are very similar to those of the papers which used the FDM-FCT method on structured grids. Thus we can conclude that the proposed FEM-FCT method is more efficient than the conventional FDM-FCT method by virtue of the reduction in computational grids number.

• Fisheries and Aquatic Sciences
• /
• v.1 no.2
• /
• pp.269-275
• /
• 1998

Spider crabs, Libinia emarginata, were eyestalk-ablated unilaterally and bilaterally to manipulate endogenous methyl farnesoate (MF) to increase during the embryogenesis. Endogenous MF were measured weekly over the embryogenesis of the crab, using HPLC with the aids of GC/MS and MS database (CAS 010485-70-8) for the identification of the hormone. Initial MF titers both in the hemolymph and embryos of intact control were at bottom levels and the hormone concentrations kept unchanged (p<0.05), reflecting physiological unnecessaries of the hormone in the embryogenesis. Eyestalk ablation significantly stimulated the crabs to increase endogenous MF in both tissues (p<0.0l). In the response of the embryos to the increased MF, no growth stimulations were observed, at least, in the first part of embryogenesis. The increased mortalities and immature sheddings of embryos resulted from the crabs under the influence of elevated MF in both tissues, instead, suggesting that the elevated MF against the crab's requirement blocked the normal developmental process of the crab embryos. These data can give crustacean endocrinologists some insights to understand the effects of the hormone on the crustacean reproduction studied previously in which JH analogs ambiguously affected the crustacean reproduction depending on the reproductive stages. The data also can give shrimp aquaculturists some implication of a possible generation of unfavorable shrimp seeds attributed to elevated egg MF originated from their eyestalk-ablated mother shrimp.

• Korean Journal of Food Science and Technology
• /
• v.36 no.2
• /
• pp.262-267
• /
• 2004

Processed foods were developed using amaranth starch and flours. Amaranth seeds were untreated (UT), defatted (DF), germinated (GM), roasted (RT), popped (POP), and extruded (EX1 and EX2). Amaranth flours showed A-type pattern on X-ray diffractograms, while crystallinity was not observed in POP, EX1, and EX2. POP and EX1 showed highest (740.3%) and lowest (38.5%) water-binding capacities, respectively. Transmittances of RT, POP, EX1, and EX2 flour suspensions were higher than those of others. Transmittance of amaranth starch and flours differed with processing methods. RT, POP, EX1, and EX2 showed higher transmittance at $60^{\circ}C$. Initial pasting temperature of amaranth flours by RVA were $68.1-73.0^{\circ}C$, and peak viscosities of GM and RT were 31.6 and 401.1 RVU, respectively. Melting endotherms of POP, EX1, and EX2 were not observed in DSC thermograms.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.23 no.4
• /
• pp.59-67
• /
• 2020

In this study, the effects of windbreak fences composed of natural vegetation on one-year-old seedlings were analyzed to develop restoration methods for an endangered subalpine species, the dwarf Siberian pine (Pinus pumila (Pall.) Regel). One-year-old seedlings were planted in 2016 by sowing seeds that had been collected from the Daecheongbong area on Mt. Seoraksan, South Korea, in 2014. The area near Daecheongbong was selected as the experimental site, and treatment and control plots (2m×2m) were installed at the site. To analyze the effects of wind protection, windbreak fences were constructed in the treatment plots using hairy Korean rhododendrons (Rhododendron mucronulatum Turcz. var. ciliatum Nakai) from the surrounding area and weather stations were installed to investigate atmospheric temperature, humidity, and wind speed. In all control plots without windbreak fences, dwarf Siberian pine seedlings were killed by strong winds seven months after planting. In contrast, the average survival rate of the seedlings in treatment plots was 96.7% after seven months, 64.2% after two years, and 45% after three years, with most (85.3%) of the seedlings showing good initial root establishment. Accordingly, windbreak fences composed of natural vegetation are suitable for promoting the early establishment of seedlings in the restoration of dwarf Siberian pine stands.

• Journal of the Korean Society of Tobacco Science
• /
• v.17 no.1
• /
• pp.27-32
• /
• 1995

A new flue-cured tobacco mutant line BU 8832-85 was developed at Taegu Experiment Station, Korea Ginseng and Tobacco Research Institute in 1994. KF 8832-85 was resulted from a cross of flue-cured cultivars NC 95$\times$NC 2326, and developed by a pedigree system of breeding ; initial selection was made by plant type and resistance to bacterial wilt(BW) disease(heudomonas solanaceamm) in the F2 generation under the natural field conditions infested with the pathogen. One white flowered plant was occurred by spontaneous mutation in a certain line among the F3 generatioin while the others were pink. Six plants from the seeds by selfing were selected at the field infested with the pathogen among 240 populations with white flowering in the F4, KF 8832-85 was selected based on yield and leaf quality trials among 6 lines in Fs generation. BCF 8832-85 was compared with its Parent for certain agronomic and chemical characteristics at Taegu Experiment Station in 1993 and 1994. The results showed that KF 8832-85 have white flower, the stalk height was approximately that of NC 2326 but averaged about loom taller than NC 95. It produced ground suckers as much as NC 95, and did not breakdown leaf at the same as WC 2326. KF 8832-85 have high resistance to bacterial wilt disease. Yield of KF 8832-85 was 10 and 18% higher then that of NC 2326 and WC 95, respectively. Price per Kg was equal to that of NC 2326. The contents of nicotine and reducing sugar did not differ significantly from NC 95, while total nitrogen was significantly lower than NC 95. Therefore, the new mutant line is genetically stable for agronomic and chemical characteristics and provides a source of bacterial wilt disease resistance for use in breeding resistant flue-cured cultivars. Key words : Mutant line, White flower, Spontaneous mutation.

• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.739-744
• /
• 1998

Changes of volatile flavor compounds in sesame oil during industrial process (roasting temp. $225{\pm}2^{\circ}C$, roasting time 15 min) were investigated. Total volatile flavor compounds of 1 st expressed oil from roasted sesame seeds were 536.3 ppm, and those of 2nd expressed oil from sesame seed cake, residue of 1st expression, were 266.8 ppm. Those of 1st filtered oil, fixed oil and 2nd filtered oil were 472.2 ppm, 472.4 ppm and 443.0 ppm, respectively. Volatile flavor compounds were gradually decreased during processing. Top notes $(peak{\;}No.1{\sim}26)$ playing an important role in the aromatic character of sesame oil, of 2nd expressed oil were markedly reduced (70.67% of initial content). Especially pyrazine compounds showed the largest reduction in 2nd expressed oil. Total volatile flavor compounds of fixed oil, filtered oil were reduced slightly.