• The Korean Journal of Pesticide Science
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• v.14 no.4
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• pp.473-477
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• 2010

Cucumber green mottle mosaic virus (CGMMV) is one of major plant viruses infecting cucurbitaceous crops via soil or infected seeds. This study investigate ecology of infection of CGMMV in soil, and control tactics of this virus with soil hygiene and crop rotation. This virus was survival to 50% in soil without host plants for 17 months and had high vitality in debris of infected plant over 1 year. Infection rate of CGMMV was 1.0~3.6% in control soil and 12~36% in soil transplanted with wounded root of watermelon. It showed that wounded root may affect severity of soil infection. Rotation between rice and watermelon caused dramatical reduction from 76.8% in repeated cultivation to 7.3% of progeny infection by CGMMV. Therefore, it is suggested that crop rotation be effective for control of CGMMV.

• Korean Journal Plant Pathology
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• v.13 no.3
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• pp.184-190
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• 1997

Lesion enlargement of ginger rhizome rot was most rapid at 35~40 C, but delayed greatly as temperature decreased. Time needed for a killing a ginger plant, 22~25 cm long, was about 5 days at 35~40 C, but was 15 days at 15 C in a growth chamber test. Higher RH above 90%, higher soil moisture level above 80% of maximum soil moisture capacity, and deeper planting below 4cm enhanced the lesion development on ginger stems and rhizomes. Pythium myriotylum existed in field soil as forms of hyphal portion, hyphal swelling body, or oospore- or zoospore-like bodies, and served as the origin of its colonization. Inocula of P. myriotylum was randomly distributed in soil surface around ginger plants, but its density was decreased as increasing soil depth with the highest density at 0~10 cm soil depth. Population density of P. myriotylum did not vary significantly between the rhizoplane and the rhizosphere soil of a ginger plant, but differed greatly between the disessed and healthy plants with several to several hundreds times higher population in the diseased plants. A positive curvilinear relationship was found between P. myriotylum density and ginger rhizome rot severity.

• Journal of Life Science
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• v.34 no.6
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• pp.426-433
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• 2024

The environmental stress that plants are most susceptible to is water stress. Abscisic acid (ABA) is a plant hormone synthesized by plants to counteract environmental stress. The role of stomata in plants is to allow the synthesis of sucrose by absorbing CO₂, which greatly affects photosynthetic activity. In addition, stomata are pathways for transpiration, which releases H₂O and help establish a water potential gradient that allows plant roots to continuously absorb water and inorganic substances from the soil. Plants have a mechanism to minimize water loss by closing their stomata when exposed to water-stressed environments. The most well-studied hypothesis concerning the mechanism of stomatal closure is the response to water stress. When a plant receives sufficient water, its stomata open during the day and close at night due to its circadian rhythm. In addition, stomatal closure occurs when the concentration of CO₂ in the intercellular space increases. However, the mechanism of stomatal closure due to circadian rhythm and increased CO₂ concentration in the intercellular space is not well understood. When plants undergo water stress, the increased concentration of ABA in the guard cell cytoplasm induces an increase in Ca²⁺ concentration, resulting in cytoplasmic depolarization. As a result, the outward K⁺-channel of the tonoplast and the slow-type anion channels SLAC1 and SLAH3 are activated, releasing K⁺, Cl^-, and malate^2-, causing the stomata to close. Therefore, in this paper, the mechanism of stomatal closure caused by water stress was investigated.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.175-182
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• 1986

A study was conducted to survey the fauna and the field density ofp lant parastic nematodes on important cash crops in Korea. Studies were carried out with sampling about five hundred grams of soil around roots of eighteen different kinds of crops from fifty five locations throughout the country. Nematodes were elutriated from over three thousand soil samples, and identified into sixteen different genera. Among them Ditylenchus species were found to be the most abundant in fields of garlic and onion, Helicoty-lenchus of sesame, chinese cabbage and mulberry, Meloidogyne of red-pepper, tomato, cucumber and peanut, Pratylenchus of mulberry and peach, Pratylenchus of apple, Chinese cabbage and radish, Trichodorus of potato, and Xiphinema of peach and potato. Field density of Meloidogyne species was increased with the longer continuous cultivation of red-pepper in the same field.

• Korean Journal of Plant Tissue Culture
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• v.22 no.3
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• pp.121-126
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• 1995

Diploid plants were obtained by anther culture of tetraploid poplar(Populus alba L. X P.glandutosa Uyeki). The effect 2,4D on callus formation from anther culture was greater than any other auxins tested. The highest average number of multiple shoots per callus was obtained when zeatin was used at levels of 6-8 ${\mu}$M. Regenerated shoots were excised and transferred to MS basal medium. Rooted plantlets were subsequently transferred to pots containing artificial soil mix. Finally 100 plane were transplanted in nursery located in forest Genetics Research Institute. for the 300 anther clones growing in greenhouse for 6 months after transplanting, 33% were slow-growing, 47% were rapid-growing and 20% had huge leaf size with rapid-growing characteristics. Chromosome study showed a narrow range of variation from diploid to tetraploid. DNA polymorphism studies using various RAPD markers revealed some extend of differences among the anther-clones in their band pattern.

• The Journal of the Convergence on Culture Technology
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• v.5 no.4
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• pp.373-378
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• 2019

In the marine area, the salt concentration in the soil increases, and the inland heavy metal pollution increases the damage of plants. In the inland industrial development area, researches on the genetic resources of plants together with the heavy metal accumulation of Co, Ni, Zn, and so on are required. Both of these problems have caused scientists to work hard to find plants that are likely to cause stress in plant roots. In this study, seeds of Arabis stelleri var. japonica collected near the shore were used for germination. The growth and development and tolerance of both Arabis and Arabidopsis seeds were investigated under laboratory culture conditions. As a result, Arabis showed resistance about 3 times in 250 mM nickle and cobalt, and more than 4 times in 1 mM zinc when compared to Arabidopsis. The tolerance of Arabis to Na salts increased by 20% or more at 50 mM concentration and Arabis was resistant to heavy metals and salt concentration. The accumulation of Na ions in the body was measured as a preparation for studying the intracellular mechanism. As a result, it showed a further decrease in resistance to ground water roots. It is considered that the activity of the exporting gene is important rather than the mechanism of accumulation.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.77-82
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• 1999

Three floating islands have been constructed for water quality improvement for a polluted irrigation reservoir. Each floating island consists of 10 segments. Each segment hay an area of $16m^2$(4×4m) and is made of wood frames and floats(polystyrene foam). We planted three species of aquatic macrophytes(Typha angustifolia, Zizania latifolia, and Phragmites australis) in floating island on June, 1998. They grew very well without death. We would like to evaluate Phragmites australis is the most suitable aquatic macrophyte that could be planted in a floating island because it maintained the best balance of its root and shoot among them. During their grown period, net primary productivity of Typha angustifolia was $962gDM/m^2$, Zizania latifolia was $1,115gDM/m^2$, and Phragmites australis was $523gDM/m^2$. From these data, it would be estimated to 5.0Kg uptake of nitrogen by aquatic macrophytes and phosphorus 0.8Kg in 3 floating islands. The floating islands worked well as a habitat of fish and prawns. Many kinds of insect lived on the floating islands. The floating island has not only the function of water quality treatment but also several advantages: improvement of landscape and species diversity; low cost of maintenance; low technology; unnecessary of energy; less susceptible to variations in pollutant loading. It could be evaluated a good measure of water quality improvement for an irrigation reservoir. However, it should be intensively studied to develop more light, strong, durable and low-priced frames for efficient floating islands.

• 보존과학연구
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• s.33
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• pp.5-17
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• 2012

An Ola leaf manuscript, which consists of words carved on an Ola leaf and is filled up with a mixture of herbal oils made from Vateria acuminata Hyne and charcoal, is one of the native writing media in Sri Lanka. According to historical records, Ola leaf manuscripts had been used from the 1st to the 18th century A.D. From the recent findings that Ola leaf manuscripts have been preserved well for the past 400 years and are in good state of preservation, it is supposed that herbal oils preserve Ola leaves against environmental and biological factors such as fungi and insects. To evaluate the anti-biological susceptibility of the herbal oils, the molds isolated from wooden printing blocks in Janggyeong Panjeon of Haeinsa Temple in South Korea and bacteria and fungi isolated from Ola leaves were cultured. After spreading the microorganisms suspension on an agar plate, a disk paper containing a certain volume of herbal oil was placed on the agar plate. It was found in the experiment that herbal oil exhibits a clear zone, which is optically clear and inhibits the growth of microorganisms, against some molds and bacteria. The study results indicate that the herbal oil from the plant Vateria acuminata Hyne has the anti-bacterial and anti-fungal properties.

• Korean journal of applied entomology
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• v.52 no.4
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• pp.327-333
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• 2013

Plant parasitic nematodes were isolated from 274 soil samples collected from soybean fields in Korea. Nematode importance rating in soybean is proposed based on this study and by reviewing other reports. Soybean cyst nematode, Heterodera glycines is the most important nematode species and rated as $1^{st}$ because it detected from 38%(range 25-51%) of soil samples with high density except Jeju province. Root-knot nematode, Meloidogyne spp. is rated $2^{nd}$ and is more widely distributed in southern provinces, Gyeongnam, Jeonnam, and Jeju province (detection rate ranged 16-44%). Pratylenchus is rated $3^{rd}$ and is more frequently detected from northern provinces such as Gyeonggi and Gangwon (detection rate ranged 10-13%). Helicotylenchus is rated $4^{th}$ and is particularly important in Jeju province (detection rate is 62% and numbers averaged 571 nematodes/$300cm^3$ soil), which is the main production area for sprouting soybean in Korea. Tylenchorhynchus, Paratylenchus, Criconema, Criconemoide, Mesocriconema, Ogma, Xiphinema, Paratrichodorus, and Trichodorus occur in low frequency and density, thus they are rated to $5^{th}$. We propose to delete following nematode genus from the list of soybean parasitic nematode in Korea because their parasitism on soybean is unconfirmed or negligible; Tylenchus, Aphelenchus, Aphelenchoides, Ditylenchus, Hirschmanniella immamuri, Basiria graminophila, Psilenchus, and Pseudhalenchus. Therefore, we revised 30 species in 16 genera as soybean parasitic nematodes in Korea. Importance rating is $1^{st}$ Heterodera glycines, $2^{nd}$ Meloidogyne spp., $3^{rd}$ Pratylenchus spp. and $4^{th}$ Helicotylenchus spp. especially in Jeju province.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.503-519
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• 2014

This study was conducted to investigate ginger growth and its nutrient uptake depending on changes of soil properties as affected by applications of green manure crop and/or charcoal in continuous cropping system. The green manure crops applied were barley and hairy vetch, and charcoal was additionally treated in selected plots as a soil conditioner. Experimental plots were prepared as Plot 1 (control), Plot 2 (barley of 8kg $10a^{-1}$), Plot 3 (hairy vetch of 12kg $10a^{-1}$), Plot 4 (charcoal of 1,000kg $10a^{-1}$ and barley 8kg $10a^{-1}$), and Plot 5 (charcoal of 1,000kg $10a^{-1}$ and hairy vetch of 12kg $10a^{-1}$) with two different soil conditions (high clay content, HCC and low clay content, LCC). When comparing selected chemical properties of soils before and after cultivating ginger plant, soil pH decreased from 6.9~8.1 to 6.8~7.6, and electrical conductivity (EC) also declined from $0.45{\sim}1.25dSm^{-1}$ to $0.30{\sim}0.61dSm^{-1}$. However, the content of soil organic matter (SOM) and total nitrogen (T-N) increased. Thus, the soil chemical properties were improved with the applications of green manures and charcoal. Also, macro- and micro-nutrient contents of ginger plants in the different plots were various between normal and diseased plants grown in soils with HCC and LCC. In particular, the concentration of manganese (Mn) was 3~4 folds higher in the diseased plant than in the normal plants. Ginger growth status and yield was relatively improved with the applications of green manures and charcoal as comparing with control plot. Especially in the Plot 4 with LCC, the ginger plant was not infected by root-rot disease.