• The Plant Pathology Journal
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• 제28권2호
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• pp.191-196
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• 2012

Periwinkle seedlings (Cantharanthus roseus) were inoculated with jujube witches'- broom (JWB) phytoplasma via grafting to analyze the migration of JWB phytoplasmas within the host plant. The phytoplasmas were detected using nested polymerase chain reaction (PCR) and fluorescence microscopy. Fluorescence microscopy was a simple and easy method of detecting phytoplasmas; however, it was not sufficiently sensitive to detect very low phytoplasma concentrations. Therefore, the migration of JWB phytoplasma was investigated through PCR. The first migration of JWB phytoplasma from an infected tissue to healthy tissues occurred late. After grafting, the phytoplasmas moved from the inoculated twig (or scion) to the main stem, which took 28 days. Afterward, the phytoplasma migrated faster and took less than 4 days to spread into the roots from the main stem. All twigs were then successively colonized by the JWB phytoplasmas from the bottom to the top. JWB phytoplasma was detected via nested PCR in all parts of the periwinkle seedling 82 days after inoculation. Based on these results, the inoculated JWB phytoplasma appeared to migrate downward to the roots along the main stem during the early stages, and then continued to move upward, colonizing twigs along the way until they reached the apex.

• Journal of Plant Biology
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• 제28권4호
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• pp.285-296
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• 1985

To examine the differentiation and transition of vascular system in Prunus davidiana FR., the mature embyro and developing seedlings were embedded in paraplast and treated by clearing method. In mature embryo, the procambium was connected with the epicotyl-hypocotyl-radicle axis and cotyledons, whereas protophloem and protoxylem were restricted primarily to the mid-vein and two lateral veins of the cotyledonary base. With the onset of germination, protophloem and protoxylem were differentiated both acropetally and basipetally from the cotyledonary base. The first and second leaf traces appeared in the cotyledonary node, and then differentiated bidirectionally toward the epicotyl and the root tip. The 3rd to 6th leaf traces were connected with the cotyledonary traces in hypocotyl. At the part of the root tip, the xylem was a diarch. As the first and second leaf traces were superimposed at the middle part of the root, the diarch xylem was changed to a tetrarch. As the cotyledonary traces were diverged below the root base, the tetrarch xylem was changed to an octarch. It was suggested that the vascular system of the epicotyl might be superimposed on that of the cotyledon-hypocotyl-root during the formation of the primary vascular system of Prunus davidiana.

• 한국약용작물학회지
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• 제17권6호
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• pp.415-420
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• 2009

This study was carried out to select economical byproduct composts as the substitute for the traditional organic fertilizer, Yacto, in the cultivation of ginseng seedlings, and to investigate the application method of a selected compost. Among tested byproduct composts, popped rice hull compost was the best substitute for Yacto, while the application of domestic animal manure composts resulted in red skinned roots of ginseng seedlings. Optimal mixing ratio of the popped rice hull compost with virgin soil (fine sand) were 3~4 : 1 in bulk, showing the same root yield compared to that of conventional seedbed soil. When the popped rice hull compost was lower than $1\;{\pm}\;0.1%$ in nitrogen content, the expeller cake of oil seed was added to seedbed soil to rise nitrogen content until $1\;{\pm}\;0.1%$.

• 한국농림기상학회지
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• 제10권3호
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• pp.107-112
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• 2008

"Jeung-Bo-San-Lim-Gyeong-Je" (meaning "Revised Forest Management") has been well recognized as the informative document that introduces scientific knowledge and experiences of Korean ancestors regarding weather and climate. The tradition of Gwan-Cheon-Mang-Gi(i.e., empirical forecasting of short-term weather phenomena based on the status of cloud or sky) has been continuously utilized as a civilian weather forecasting method and even for very short-term weather prediction by operational forecasters these days. This agricultural technology textbook, published during the Great King Youngjo in Chosun-Dynasty, may be regarded as a poorly written document from the modern standpoint. Nonetheless, this study demonstrates that by and large the empirical knowledge contained in the book is indeed science based although their applications are limited to several hours for local forecasts in agricultural practices and daily living. For example, the wisdom of keeping water at an optimum level in a paddy field after sowing to prevent young seedlings from late frost damages was not at all different from the present technique of vinyl covered seedling nursery.

• 아시안잔디학회지
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• 제9권3호
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• pp.173-185
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• 1995

Hydroseeding technique is a very popular method of revegetating slope areas through the control of soil erosion and stability by seeding grasses. This study was conducted to select turfgrass species and cultivars for hydroseeding. Experiment plots were established on various soil types and environmental conditions at Singar-Ansan high-way construction site. The investigation was designed in three cutting, one back-filling and other three spare sites with various seed mixtures. Results indicated that combinations of seed mixtures influenced seed germination and rates of surface cover. In a view of long term, vegetation shifts should be influenced by characters of slopes and micro-climate conditions. Hydroseeding did not show good results on rocky slope areas. Revegetation was only going on where there had soil. The combination of seed mixture with a higher rate of perennial ryegrass had relatively good revegetation with faster germination and seedling growth. Improved turf-type tall fescue Arid ⓡ and Falcon ⓡ seemed to have good environ-mental adaptation and drought tolerance. Wild or old type cultivars showed relatively slow green-up in spring and growth rates at the next year of seeding. For the harmonious landscaping with surrounding area, the combination of native grass mixture with cool-season grasses had good results. Slow and low revegetation rate at hack-filling site seemed to be caused by the poor development of capillary tubes in sub-soil. It was shown that a high correlation between seed germination and revegetation rate, and between three-month later coverage rate and final rate. The evaluation of coverage rate after three month seems to he acceptable to decide the accomplishment of hydroseeding results on rode side slopes.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.212-226
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• 2002

North American ginseng production may have been maximized in the traditional growing areas in the last decade and further increases may be in woods grown root, for niche markets. The marketplace demands high quality roots. Most problems leading to low quality roots start with the grower and can be avoided. These include poor site selection, inadequate soil drainage, untimely and poorly applied pesticides, and neglect of good sanitary practices. Selection of low lying sites increased the plant damage from frost in Ontario in May 2002. Seeding is still the major method of propagation of ginseng in spite of some success in culturing different parts of the plant. Opportunities exist for shortening the stratification period of North American ginseng seed to allow spring planting. This may reduce disease incidence. Since only one-third of ginseng seed sown ultimately produces plants harvested after 3 years any approach that reduces disease incidence and improves seed germination, seedling emergence and crop stand must be pursued. Disease is the major problem in ginseng cutivation from seed stratification, soil preparation prior to planting, right through to drying of the roots. Replant disease remains as an unresolved problem and needs full characterization and new approaches for control. Much progress has been made in research and related extension activities in disease control although challenges will arise such as with Quintozene and its replacement with Quadris for control of diseases caused by Rhizoctonia. Decreased labor populations and increased associated costs for ginseng production are causing rapid mechanization in every aspect of the ginseng industry. Engineers, machinery dealers, and fabricators, and growers are being challenged to increase efficiency by mechanization.

• 한국환경복원기술학회지
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• 제26권1호
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• pp.61-68
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• 2023

In North Korea, the production of courage tombs continues, and it is known that the activity rate is higher than that of old tombs. However, pot seedling are planted using hoes and shovels used for planting old tombs with exposed roots and low activity rates. This is believed to result in excessive force when stepping on the container grave with a hoe in the planting process, resulting in the collapse of the container grave or the waste of labor due to the creation of unnecessary planting holes. Therefore, when planting courage graves at North Korean afforestation sites, it is necessary to improve the work of making planting holes using general hoes in a way that improves labor productivity in a more efficient manner. As part of inter-Korean technical cooperation to improve the North Korean afforestation method, this study was conducted with the aim of developing efficient container seedlings and using them for North Korean forest restoration projects. It is believed that developing planting equipment exclusively for container graves for forest restoration in North Korea in South Korea and providing equipment and production technology to North Korea can contribute to the development of forest restoration technology in North Korea. If the Yonggeomyo Development Planting Equipment is provided to North Korea, it will be a realistic inter-Korean forest cooperation project to avoid international sanctions by recognizing the excellence of the development products by directly using its own materials through technical cooperation.

• Journal of Ecology and Environment
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• 제46권1호
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• pp.8-17
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• 2022

Background: Parthenium hysterophorus L. (Asteraceae; hereafter Parthenium) is an invasive alien species of global significance because of its' negative ecological and socioeconomic impacts. This species is spreading rapidly from lowland Tarai to Middle Mountain regions in Nepal. In the present study, we analyzed the impacts of Parthenium on plant community composition including their soil seedbank in subtropical grasslands located in central Nepal. Data was collected in a 10 m long transects passing through areas of high (> 90% cover), medium (40%-60%) and low (< 10%) levels of Parthenium cover using a plot of 1 m². Altogether, we sampled 90 plots in 30 transects. Seedling emergence method was used to estimate soil seedbank density in the soil samples (0-10 cm depth) collected from the plots with high Parthenium cover. Results: There was no significant difference in the plant species richness at different levels of Parthenium invasion whereas there was a significant change in the species composition of above ground flora due to Parthenium invasion. There was also a significant difference in species composition between soil seedbank and aboveground flora in the highly invaded plots. Parthenium was the most dominant in soil seedbank, contributing 65% to the total soil seedbank. Conclusions: Our study suggests that Parthenium has considerable negative impact on the native grassland flora, and the dominance of Parthenium in the soil seedbank means there is a challenge for its management. It also suggests the need of monitoring the soil seedbank dynamics while managing Parthenium weed.

• 생물환경조절학회지
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• 제22권4호
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• pp.322-327
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• 2013

본 실험은 건전한 토마토 접목묘 생산을 목적으로 활착 및 순화기에 광환경을 달리하여 접목부위에 캘러스의 형성을 도우며, 접목묘의 광합성이 원활할 수 있는 적정 광환경을 구명하고자 수행하였다. 암 처리를 하지 않는 방법(Non), 접목부분만 암 처리하는 방법(Part), 2일간 암 처리 후 순화실로 옮기는 방법(Day-2), 4일간 암 처리 후 순화실로 옮기는 방법(Day-4) 등으로 처리하였다. 접목은 1.5mm 실리콘 튜브를 이용하는 방법으로 하였으며, 부분 암 처리를 위해 튜브를 끼워 둔 접목부분을 알루미늄호일로 감싸주었다. 연구결과, 활착율은 2일간 암 처리 후 순화실로 옮기는 방법(Day-2)에서 가장 좋았으며, 유묘의 SPAD 값과 묘소질 및 초기 수확량은 모두 접목부분만 암 처리한 방법(Part)에서 가장 우수하였다. 또한 경제성 분석에서도 부분 암처리 방법이 타 처리에 비해 추가 비용이 발생하지만, 초기 수확량이 많아서 타 처리보다 월등히 높은 소득이 예상되었다. 따라서 토마토 접목시 가장 적절한 광처리는 접목부분만 암 처리한 방법(Part)이 가장 좋은 방법으로 판단되었다.

• 한국패류학회지
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• 제27권4호
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• pp.337-343
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• 2011

일본(기수)재첩 유생사육을 위한 최적조건을 파악하기 위하여 수온, 염분, 유생 수용밀도, 먹이생물 종류 및 공급량, 채묘방법에 따른 성장과 생존율을 조사하였다. 일본(기수)재첩의 부유유생은 $24^{\circ}C$와 $27^{\circ}C$에서 빠른 성장을 보였으며, $18^{\circ}C$와 $21^{\circ}C$에서 50% 이상의 높은 생존율을 보임으로서 유생 사육을 위한 적정 수온은 $21-24^{\circ}C$이며, 최적수온은 $24^{\circ}C$ 이었다. 또한 염분 3 psu 이상에서 성장과 생존이 가능하였으나 적정 염분은 6-9 psu 이었다. 유생밀도별 사육시험에서 1 ml당 1-10 개체에서 높은 성장과 생존율을 보였으나 경제성을 고려한 적정 유생사육 밀도는 1 ml당 10 개체였다. 먹이생물에 따른 유생의 성장과 생존율은 Isochrysis galbana, Pavlova lutheri 및 Chaetoceros calcitrans를 혼합하여 10,000-20,000 cells/ml의 밀도로 공급하는 것이 가장 효과적이었다. 성숙유생의 채묘는 모래저질에서 성장과 생존율이 유의하게 효과적이었으며, 특히 0.25 mm 이하의 미세사질에서 높은 생존율을 보였다.