• Plant Biotechnology Reports
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• v.3 no.3
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• pp.175-182
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• 2009

Simple, reproducible, high frequency, improved plant regeneration protocol in Eastern Cottonwood (Populus deltoides) clones, WIMCO199 and L34, has been reported. Initially, aseptic cultures established from axillary buds of nodal segments from mature plus trees on MS liquid medium supplemented with $0.25mg\;1^{-1}$ KIN and $0.25mg\;1^{-1}$ IAA. Nodal and internodal segments were found to be extra-prolific over shoot apices during course of aseptic culture establishment, while $0.25mg\;1^{-1}$ KIN concentration played a stimulatory role in high frequency plant regeneration. Diverse explants, such as various leaf segments, internodes, and roots from in vitro raised cultures, were employed. Direct plant regeneration was at high frequency of 92% in internodes, 88% in leaf segments, and 43% in root segments. This led to the formation of multiple shoot clusters on established culture media with rapid proliferation rates. Many-fold enhanced shoot elongation and growth of the clusters could be achieved on liquid MS medium supplemented with borosilicate glass beads, which offer physical support for proliferating shoots leading to faster growth in comparison to semi-solid agar or direct liquid medium. SEM examination of initial cultures confirmed direct plant regeneration events without intervening calli. In vitro regenerated plants induced roots on half-strength MS medium with $0.15mg\;1^{-1}$ IAA. Rooted 5- to 6-week-old in vitro regenerated plants were transferred into a transgenic greenhouse in pots containing 1:1 mixture of vermicompost and soil at $27{\pm}2^{\circ}C$ for hardening and acclimatization. 14- to 15-week-old well-established hardened plants were transplanted to the field and grown to maturity. The mature in vitro raised poplar trees exhibited a high survival rate of 85%; 4-year-old healthy trees attained an average height of 8 m and an average trunk diameter of 25 cm and have performed well under field conditions. The regeneration protocol presented here will be very useful for undertaking genetic manipulation, providing a value addition to Eastern Cottonwood propagation in future.

• Korean Journal of Environmental Agriculture
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• v.18 no.2
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• pp.164-168
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• 1999

For investigating transfer factors of $^{137}Cs$ in the arable land of Korea, mature crop plants and topsoils were collected from paddy and upland fields located at 33 areas of the country and $^{137}Cs$ concentrations were measured by ${\gamma}-spectrometry$. The $^{137}Cs$ concentrations in soil were in the range of $0.7{\sim}17.7$ Bq/kg-dry in the paddy fields and $1.2{\sim}27.8$ Bq/kg-dry in the upland fields. The $^{137}Cs$concentrations in hulled seed, detected for 12 areas only, were in the range of $0.019{\sim}0.111$ Bq/kg-dry and those in Chinese cabbage, detected also for 12 areas only, were in the range of $0.012{\sim}0.066$ Bq/kg-fresh. Soil-to-plant transfer factors of $^{137}Cs$ were in the range of $1.2{\times}10^{-3}{\sim}1.1{\times}10^{-2}$ for hulled seed and $6.8{\times}10^{-4}{\sim}1.7{\times}10^{-2}$ for Chinese cabbage. Inboth plant stuffs, the factor tended to decrease with increasing soil organic matter or cation exchange capacity and, in hulled seed, it tended to increase with increasing soil clay content. No statistical significance was, however, found in all those relationships. Present results can be utilized for estimating radiation risk resulting from the food consumption by Korean people and deciding agronomical counter-measures at the time of an nuclear accident.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.2
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• pp.77-82
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• 1998

Aerenchyma development in rice (Oryza sativa L.) roots is quite important for adaptation to waterlogged or reduced soil conditions. Anatomical observations were carried out to clarify the development of schizogenous and lysigenous aerenchyma in elongating crown roots of rice. The crown roots of 3rd and 4th phytomer were taken from rice plants of the 8th leaf stage grown by hydroponic culture. The schizogenous intercellular spaces in the cortex of crown root tip were observed using a light microscope with semi ultra-thin sections and the lysigenous aerenchyma in mature tissue of crown root were observed using a cryo scanning electron microscope (cryo-SEM) with freezing fracture method. The schizogenous intercellular spaces in the root tip exist obviously in the middle portion of cortical cell layers close to the root-root cap junction, but not in root cap, stele and outer cell layers of cortex. The air spaces were formed at the junction of four neighbouring cells of inner cortex in the transverse sections, and between longitudinal cell layer connected along the root axis. Although many of those spaces were filled with liquid, some spaces seem to exist as air spaces. The lysigenous aerenchyma in the cortex, which hardly filled with liquid, emerged at 3-4 cm segment from the root tip and increased toward the basal region of root axis. The developing process of lysigenous aerenchyma was primarily separation of a radial row of cells caused by the shrinking and collapsing of cortical cells and then formation of septa along the radial cell rows by the fusion of cell wall with each other. These results suggest that the schizogenous and lysigenous aerenchyma playa role as a passage for the movement of oxygen into the root tip region where oxygen is required for respiration.

• Korean Journal of Medicinal Crop Science
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• v.4 no.3
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• pp.265-268
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• 1996

According to the research of the cultivation result of Gardenia for 5 years to investigate its cultivation conditions and problems, the development of the variety with early mature and high yielding is urgent and that of rooted cutting cultivation method by the experiment of rooted cutting, bed soil, growth regulator and cutting period are pressing. The development of cultivation method with planting year, planting density, supplementary period and amounts of supplementary of Gardenia planted on growing field are required and for the disease and insect pest control, the research of the cultivation method with disease and insect pest resistance is ne­eded by auxotrophic fertilizing and organic agricultural method, not by agriltural chemicals.

• Journal of Plant Biotechnology
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• v.32 no.4
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• pp.281-285
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• 2005

To establish the mass proliferation system of Ardisia pusilla DC, the shoot tips of Ardisia pusilla DC were cultured on the MS and half-strength MS medium supplemented with $0{\sim}5.0$ mg/L BA or $0{\sim}0.5$ mg/L thidiazuron(TDZ), respectively. A few multiple shoot formation observed when the shoots were cultured on MS medium containing TDZ. However, the frequency of multiple shoot formation was reached up to 82.4%, when the shoots were cultured on half-strength MS medium supplemented with 0.5 mg/L BA. Also the number of shoot per explant was 7.1. To promote rooting from multiple shoot, newly formed shoots were transferred to half-strength MS medium containing 0.5 mg/L IBA or 0.5 mg/L NAA, respectively. Regenerated plantlets were grown to normal mature plants in soil.

• Journal of Plant Biotechnology
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• v.31 no.3
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• pp.203-207
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• 2004

To establish high frequency shoot formation from two cultivars (Cheongyangjaerae and Myungan) of boxthorn (Lycium chinense Mill.), hypocotyl segments with cotyledons from seedlings were used as explants. High frequency adventitious shoot formation (more than 80%) were obtained from hypocotyl segments with cotyledon on MS medium supplemented with 1.0 mg/L zeatin, when precultured for 3 weeks under dark conditions followed by transfer to light conditions. But there was no shoot induction in the explants cultured without preculture under dark conditions. Roots were induced from the shoots when transferred to rooting medium supplemented with 1.0 mg/L IAA for 4 weeks. Regenerated plantlets were grown to normal mature plants in soil.

• Ocean and Polar Research
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• v.26 no.1
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• pp.23-32
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• 2004

As a baseline survey for long-term monitoring on environmental change around the Antarctic King Sejong Station, distribution pattern of Deschampsia antarctica Desv., a flowering plant newly colonized were investigated qualitatively and quantitatively in both austral summer 2002 and 2003. Dispersal of the seeds and vegetative leaves by skuas might lead to the colonization into this area from neighbors in Maxwell Bay. The pioneer populations were observed around ponds and a stream of the Sejong Point in January 2002, and the maximum dispersal area was four times expanded after a year. Most of the populations were formed on the stable and well-drained substrate, which consisted of moss carpet of Sanionia georgico-uncinata (65%) and pebbles (25%), while only a few young individuals were observed on the unstable and watertight silt-sandy area. Especially, S. georgico-uncinata was being effectively utilized as their primary substrate with the soft, coarse and water-contained leaves. Also the perennial mature plants of D. antarctica were mainly formed on the moss carpet rather than pebbles. A few individuals were grown on other mosses of Polytrichastrum alpinum, Bryum pseudotriquetrum, Pohlia cruda, and Conostomum magellanicum and on a liverwort of Cephaloziella varians. We expect that dispersal of D. antarctica and the following succession to grass field will be countinuously and dynamically proceeded in this area, with the characteristics of ecological niche against the initial moss populations, on the similar continuity of environmental conditions. The continuous observations are needed with establishment of database on environmental change of micro-habitats, e.g. the water content and nutrients of soil and the underground temperature and permafrost.

• Food Science and Preservation
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• v.7 no.2
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• pp.150-154
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• 2000

The use of artificially synthesized inorganic manure for the production of fruits and vegetables gives rise to soil contamination as well as noxious effects against human. Changes in quality of strawberry (SN) cultivated with a natural organic manure developed to solve such problems were studied during storage at 4$^{\circ}$C for 2 weeks. SN showed higher weight/volume ratio and lower weight loss during storage than strawberry (control) cultivated with commercial synthetic mature. Sweetness was higher in SN (9.2 Brix) than in control (8.2 Brix), and decrease in sweetness during storage was smaller in SN than in control. Redness (b) of strawberry was 32.1 in SN and 30.2 in control, and the redness decreased during storage showing 25.2 and 23.0, respectively, after 2 weeks. Hardness was higher in SN than in control, and decrease in hardness during storage was smaller in SN than in control. Vitamin C content was slightly higher in SN than in control, and mineral contents were generally higher in SN than in control.

• Korean Journal of Agricultural Science
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• v.46 no.4
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• pp.897-905
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• 2019

To compare the composting characteristics of food waste supplemented with various bulking agents, aerated composting was performed by mixing sawdust, ginkgo leaves, insect feces, and mushroom waste at ratios of 6 : 4 (w/w). The initial temperatures (day after treatment [DAT] 3) of the sawdust, ginkgo leaves, insect feces and the mushroom waste mixtures were 39, 58, 65, and 51℃, respectively. The DAT 3 temperature was the highest in the food waste-insect feces mixture (65℃) and the lowest in the sawdust one (39℃). However, the insect feces treatment was terminated at DAT 21 because of a high water content (70.92%). The water content (DAT 56) of the composted food waste supplemented with sawdust, mushroom waste, and ginkgo leaves stood at 51.28, 39.81, and 44.92%, respectively. Therefore, the fully mature composts satisfied the water content requirement of less than 55% as recommended in the fertilizer standards of the RDA of Korea. The results of the CoMMe-101, Solvita and seed germination index methods indicate that the mushroom waste and ginkgo leaves treatments matured relatively quicker than that of the sawdust one. Based on the above observations, it is concluded that the mushroom waste and ginkgo leaves are more effective bulking agents compared to sawdust and as such, are recommended as suitable replacements for sawdust in food waste composting.

• Journal of Environmental Science International
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• v.10 no.3
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• pp.201-208
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• 2001

To investigate the physio-chemical components and properties of aerosol particles in urban area sampling of aerosol particles was carried out in the campus of Hokkaido University, Sapporo, Japan, during snowfall. Aerosol particles were collected on millipore filter papers using a low volume air sampler. Their shapes, sizes and chemical components were analyzed by a SEM(Scanning Electron Microscope) and an EDX(Energy Dispersive X-ray). As a results, ice crystals of dendrite and column types were predominantly shown at mature and developing stage of snowfall intensity. The denerite and sector plate types of ice crystals were mainly originated from the sea but column types were come from soil. Scavenging effect by snowfall was greatly also shown at dendrite type ice crystals that embryo was fully developd. Al, Si elements were shown at high frequencies as compared with others. Na, Cl components were especially shown at high frequencies under the sea-breeze wind during snowfall. Anthropogenic aerosol particles had shown with irregular shapes and sizes, relatively. Mainly 3-7$\mu$m aerosol particles were abundant and coarse particles also could be seen during snowfall. Ca, Zn, Fe components mainly caused by spike tires from vehicles in winter season were dominant before snowfall, however the element S mainly caused by human activity was rich after snowfall. The pH values of snow in Sapporo city were higher than those at coastal area. The concentration of chemical components in aerosol particles was also affected by surface winds. Aerosol particles in urban area, Sapporo were mainly affected by human activities like vehicles and combustion with wind system. And their types were related with snowfall intensity.