• Applied Microscopy
• /
• v.41 no.1
• /
• pp.61-67
• /
• 2011

The purpose of this study is to investigate the hemp (Cannabis sativa cv. Chungsam) seed structure and ultrastructure of food reserves by scanning and transmission electron microscopy. We examined the seed coat and embryo consisting of a hypocotyl-radicle axis and two cotyledons. The seed coat consisted of exotesta and endotesta. The exotesta was a mechanical layer with lignified and elongated cells, while endotesta of the underlying layers of the exotesta was consisted of two separated cell layers. The collapsed outer layer of endotesta showed the unique reticulate structures. In cotyledon cells, protein and lipid bodies occupied most of cytoplasm. Protein bodies varied in diameter from 1.8 to $5.0{\mu}m$ and possessed a protein matrix containing electron-dense globoid crystals. Numerous lipid bodies ranged from 0.8 to $3.0{\mu}m$ in diameter were distributed around the protein bodies. During the early stages of breakdown, protein bodies rapidly changed their shape into the granular feature, however, lipid bodies were gradually degradated and fused each other. The degeneration process of protein bodies and lipid bodies of cotyledon cells might be correlated with the reports which hemp seeds rapidly lose their ability to germinate.

• Korean journal of applied entomology
• /
• v.23 no.1 s.58
• /
• pp.28-36
• /
• 1984

The relationship between ratio of virus diseases and the population of aphid vectors was studied by planting radishes(Rophanus sativus L. var. Chungsu gungjung) every 10 days and collecting aphids from April to November at Jeonju, Korea in 1982. Alate aphids were collected with yellow pan traps and virus infection ratios were checked with symptoms. The populations of flying aphids showed two peaks, one in the late May and one in the middle October in Jeonju and the population of aphid vectors also showed the same inclination. Of aphid vectors, Myzus persicae, Lipaphis erysimi, Brevicoryne brassicae, and Aphisgossypii were trapped and their percentages to total trapped aphids were $62.82\%(39,260/62,499)$ M. persicae was the most prevalent species and its percentages to aphid vectors were $82.53\%(32,401/39,260)$. High and sudden increase in virus infection ratio was found in spring while the trend in autumn was slow and low. A correlation coefficient between the population of virus vector aphid and virus infection ratio was $r=0.7414^*(\hat{Y}=8.1444+0.0551X)$ in spring and $r=0.9117^{**}(\hat{Y}=10.2590+0.463X)$ in autumn. The symptoms of radish virus diseases appeared approximately 15 days after virus vector aphids had attacked. Virus infection ratios were higher on plots where virus infected plants were reserved than on plots where they were removed.

• Korean journal of applied entomology
• /
• v.41 no.4
• /
• pp.247-253
• /
• 2002

Based on accumulated data during 1977-2001, seasonal fluctuations of migrated aphids at Daegwallyeong highlands were analyzed. In addition, rates of PLRV transmission by migrated aphids were investigated by inoculation on indicator plant, Physazis floridana, and ELISA in 2000-2001, and the change of PLRV transmission rates by aphids was compared with that of 1989-1991. The average migrated aphid population densities in 1976-1980, 1991-1995, and 1996-2000 were 575.2, 2959.4 and 2281.6, respectively, showing gradual increase in recent years. The average peak time of aphid migration was from early to mid June during 1977-2001, showing any significant differences over the years. The dominant species, however, changed slowly; before mid 1980s M. persicae flied dominantly, but after mid 1980s Aphis gossypii did. Hahm et al. (1991) reported that PLRV transmission rate of migrated aphids during 1989-1991 was 6.7-10.0%. In 2000-2001, however, migrated aphids at Daegwallyeong highland showed 10.1-11.0%. Although present PLRV transmission rate was slightly higher than that of 10 years ago, taking increased population densities and diversity of migrated aphids into account, there was no significant change of PLRV transmission rate over the years.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2004.05a
• /
• pp.35-38
• /
• 2004

1950-1960 년대의 녹색혁명은 1970년 Nobel 평화상수 상자 Norman Borlaug가 주도했었다. 제1 녹색혁명은 지구상의 가장 큰 문제점중의 하나인 기아를 해결하는지 크게 일조하였다. 많은 사람들을 굶주림으로부터 해방시켰지만 굶주리는 사람보다 더 많은 사람들이 매일 태어나고 있고, 지구의 인구증가는 지금까지 계속되고 있다. 언제까지 인구증가가 계속될 것인지, 인구증가에 따른 식량자원의 증가도 비례할 것인지는 오래전부터 인류의 관심의 대상이 되어 왔고, 자연스럽게 지구의 기아를 해결하는 제2의 녹색혁명은 과학자들의 연구를 집중시키는 결과를 낳게 되었다. 1980 년대에 미국 Monsanto 회사에서 유전공학적으로 개발한 Roundup-Ready 제초제저항성 및 Bt-살충 농작물을 선보이면서 제2의 녹색혁명이 시작되었다고 볼 수 있겠다. 이렇게 제2의 녹색혁명은 유전공학에 의한 CMO 식물$\cdot$작물에 의해 시작되었다. Monsanto 회사는 살충제 RoundUp 제초제 저항성 옥수수, 콩, 목화, Canola (유채꽃, rape seed) 등을 개발하여 이미 상업화하였다. 1960년대 쌀의 녹색혁명도 유전적으로 벼집이 짧은 품종에 의해 이루어졌다. 최근에 개발된 GMO "Golden Rice"는 비타민 A와 철분의 함량을 대폭 증대 시켜 세계 영양결핍 아동들의 건강과 시각을 향상시킬 것으로 기대되는데, "Golden Rice"는 제1회 금호국제과학상 수상자인 Potrykus (스위스공대) 교수가 개발하였다. 그러나 현재까지는 그 보급에 많은 장애물이 있다. 특히 GMO의 환경과 건강에 대한 안전성을 의심하는 사람들이 많다. 제2의 녹색혁명의 또 다른 분야는 식물의약 분야이다. GMO 개발에 적용되는 기술을 이용하면 taxol 같은 항암제, carotene 같은 항산화 영양제 등의 대량 생산이 가능해진다. 식물은 화학적 합성이 아주 까다로운 약제물질 등을 천연상태에서 합성하고 있기 때문이다. 또 식물은 lipoxygenase 효소계가 있어서 마치 천연물 석유제조공장과 같은 제조공정 capacity를 가지고 있다. 그러면 식물/식품 GMO는 안전한 것인가? 아니, KBS의 한 사회자가 말했듯이, 그리고 많은 소비자들이 믿는 것처럼 GMO는 위험한가? GMO에 대한 일반 사람들의 공포감은 Green Peace 당원들뿐만 아니라 일부 과학자들에 의해서도 조장되고 있다. 이러한 분위기 속에서 GMO에 의한 제2 녹색혁명은 Africa 대륙에서의 제1 녹색혁명이 지금도 지연되는 것과 같다고도 볼 수 있다. GMO의 환경에 대한 악영향은 과대 선전되어있는 것이 아닌가? 마치 GMO가 화학비료, 농약제보다 더 위험하다고 믿는 사람들도 많다. 나는 이러한 GMO 공포증이 과학적으로 그리고 "Risk Assessment"의 견지에서 볼 때 그 근거가 희박하다고 보여주는 몇 몇 실험 및 경험 사실들을 인용하려 한다. 그리고 올바른 Risk Assessment야 말로 한국의 21세기 BT 산업을 경쟁력 있게 하고 국민 년 소득 2만불 달성에 중요한 기여를 하게 될 것이라고 생각한다. 한국은 농토가 적고 천연자원이 빈약하다. GMO는 21세기의 생존 경쟁 산업이다. 제2의 녹색혁명은 얼마든지 가능하며, 한국은 부족한 농토와 빈약한 자원에도 불구하고 능력 있는 인적자원이 풍부하여 GMO 개발 연구에 국제적 경쟁력을 키울 수 있다. 그러나 GMO에 대한 논쟁만 하고 있으면 이미 때가 늦는다. 미국은 이미 GMO-BT 시장을 거의 완전 독점했으며, 타국에서의 논쟁과 불합리적으로 엄격한 GMO 관련 규정을 조장하고 환영한다.

• Korean journal of applied entomology
• /
• v.13 no.1 s.18
• /
• pp.25-31
• /
• 1974

This survey was aimed to accumulate basic data of aphid population at the Horticultural Experiment Station at Suweon. The yellow pan traps were setted at five locations (Fig.1.), and ran from May 1 to October 31. 1970. About one hundred and twenty species of aphids were trapped, including 24 species of plant vims vectors. Of these, dominant species were as follows: (Asterisk shows virus vector) Aphid species No. of catches * Aphis spiraecola PATCH 2,635, * Aphis craccivora KOCH 2,377, * Myzus persicae SULXER 2,111, Capitophorus hippophaes javanicus H.R. LAMBERS 2,051, Anoecia fulviabdominalis SASAKI 1,480, * Aphis gossypii GLOVER 867, * Macrosiphum avenae FABRICIUS 859, Cervaphis quercus TAKAHASHI 692, * Lipaphis erysimi KALTENBACH 645, Pleotrichophorus chrysanthemi THEOBALD 489, The above 10 species consisted $76.5\%$ of total catches and the 24 vector species consisted $55.5\%$. The curve of the seasonal occurrence of flying aphids at Horticultural Experiment Station shows bimodal, typical for the temperate region. The total number of trapped aphids at the Station from May to September, 1970, were less than that of average yearly catches at the College of Agriculture from 1967 to 1970. Thi, low numbers at Horticultural Experiment Station may attribute to the frequent spraying of insecticides from Spring to Summer on growing crops there. But the aphids population increase suddenly in the middle of October. This might be resulted from cease of insecticide applications and migration of aphids from summer host to winter host plants.

• Korean journal of applied entomology
• /
• v.53 no.3
• /
• pp.231-237
• /
• 2014

This study was carried out to investigate the pest species and their damage on Asparagus officinalis. Field surveys were conducted in asparagus greenhouse in Jeju, for four years from 2007 to 2010. Total of 16 pest species belonging to 5 orders were found as follows: Thrips tabaci, Thrips hawaiiensis, Adoxophyes honmai, Spodoptera litura, Spodoptera exigua, Helicoverpa armigera, Mamestra brassicae, Ascotis selenaria, Ectropis excellens, Geisha distinctissima, Aphis gossypii, Myzus persicae, Anomala albopilosa, Crioceris quatuordecimpunctata, Acusta despecta sieboldiana and Deroceras reticulatum. Among them, T. tabaci frequently occurred and damaged asparagus plants during the whole growing seasons. C. quatuordecimpunctata and snails caused severe damages on asparagus shoots in spring harvest season. In mid-late seasons, aphids and lepidopteran species occurred and attacked asparagus plants. Of the lepidopteran pests, S. litura, S exigua and H. armigera belonging to Noctuidae occurred moderately and fed on asparagus plants. And the pest control strategy in asparagus cultivation was discussed based on the present results.

• Journal of the Korean housing association
• /
• v.19 no.6
• /
• pp.105-114
• /
• 2008

The purpose of this study is to classify playground types according to the physical characteristics of playgrounds in child care facilities, to analyze the needs of care-givers and to evaluate the adequacy of playgrounds according to playground types. The specific areas discussed in this study were the evaluation of the adequacy in the physical characteristics of playgrounds for children's outdoor play activities by the care-givers, who assist in the outdoor play activities of children and manage safety in the playground, and a report on playground requirements of them. Data was collected from field survey carried out to investigate the physical characteristics of playgrounds of 21 child care facilities. This survey incorporated a structured-questionnaire for the purpose of evaluating the adequacy of the physical characteristics of playgrounds (location and size of the playground, play equipments, the composition of play areas, ground covers, and location of sidewalk in the playground) by the 181 care-givers from the facilities and investigating the needs of them. The major results showed the following. 1) In field survey, it was observed that while the location and the size of the playgrounds varied widely, ground cover, play equipments, and the composition of play area turned out to be identical, regardless of the location and the size of the playgrounds. 2) The playgrounds were classified into five types according to the number of children and the size of the playground. The five types include A-type as a large-scale facility/smallsize playground, B-type as a small-scale facility/large-size playground, C-type as a small-scale facility/small-size playground, D-type as a middle-scale facility/large-size playground, and E-type as a large-scale facility/large-size playground. 3) The adequacy of the physical characteristics of playground in the D-type was evaluated to be higher than that of the other types. The adequacy of the C-type playground was evaluated to be lower than that of the other types in terms of size and the composition of play areas within the playground. 4) The care-givers of the D-type and the E-type playground expressed a desire to install various play equipments, while the care-givers of the C-type playground did not wish to install play equipment. 5) Various outdoor play areas were needed in the D-type playground.

• Korean Journal of Agricultural Science
• /
• v.28 no.1
• /
• pp.18-26
• /
• 2001

Application of the Asian ladybird (Harmonia axyridis) to control several species of aphids in the plastic green houses in mind, control effects of aphid populations regulated by the Asian ladybird were observed. The green peach aphid, the turnip aphid, and the cotton aphid were present on mustard plants, Angelia utlis, ornamental kales, and egg plants at greenhouses in spring, summer, and winter. Adults and larvae of the Asian ladybird used in experiments were collected from aggregated sites at Taejon in the autumn and reared on the cotton aphid in the laboratory. In winter, more number of adults and larvae of ladybirds than in other seasons were needed to control aphid population in successively double plastic greenhouses with supplied subterranean water for keeping warmth. In spring and summer, it was possible to keep the aphid populations low when necessary by manipulating ladybird populations according to the density of aphids. On the other hand, the innate increasing rate of aphid, the aphid population density at the time of applying ladybird, the predacious ability of ladybird at specific developmental stages, and needed periods should be taken into account to control aphids. In addition, the environmental factors, for example, optimum temperature and humidity should be considered to be biologically effective when ladybirds are released to greenhouses.

• Korean journal of applied entomology
• /
• v.2
• /
• pp.16-21
• /
• 1963

The present study was undertaken to investigate the effects of different nitrogen source and rate on the growth of Fusarium oxysporum f. vasinfectum which is known to be a noticeable fungus causing the wilt disease of both sesame and cotton in Korea. From the results of this study, It was known that different N source and rate markedly affect the growth of Fusarium oxyspsrum f. vasinfectum Among four N sourses were used in this study, nitrate-N and urea-N were appropriate N source for the growth of fungus. Above all, nitrate N was the best N source because it is utilized in more extensive range of concentration in comparison with the other N source by the fungus, On the other hand, ammonia-N is of little avail for the growth of the fungus because of the formation of unusual colonies with wavy margin and bead-like mycelial cells in addition to marked reduction of mycelial growth and B sporulation of the fungus irrespective of concentration. Judging from the formation of such an abnormal colony and bead-like mycelial cell which is known to be a characteristic of 'staling-type' growth of fungi, the effect of ammonia-N on the growth of Fusarium oxysporum f. vasinfectum is similar to that of phenoxy componnds on some other fungi previously investigated by some workers. Ammonium and nitrate also was not considered to be an appropriate source for the growth of the fungus because of the formation of colonies with slight wavy margin and appreciable reduction of mycelial growth and sporulation in higher concentration than 50meq. , although much or less masking of the irregularity of colony occurs. Therefore, ammonia N alone or any other N combined with ammonia N is of little avail for the growth of Fusarium oxysporum f. vasinfectum.

• Korean Journal of Plant Resources
• /
• v.15 no.3
• /
• pp.269-278
• /
• 2002

To establish the mass propagation methods of Weigela subsessilis,, a promising native plant species for horticultural use, several factors influencing rooting from stem cuttings were evaluated. Softwood cuttings showed best rooting rate, 70~77%, in all the cutting media tested, 2.8 times more than hardwood cuttings in which perlite was best medium. The rooting from hardwood cuttings was promoted by higher concentration of all growth regulators used,500 mg.L$^{-1}$ NAA being the best with 80%. More than 80% of softwood cuttings treated by growth regulators produced roots, especially 100, 500, and 1000mg.L$^{-1}$ NAA producing 97％. Roofings from semi-wood cuttings was enhanced by all the growth regulators, except 1000 mg.L$^{-1}$ concentration in which rooting was reduce. Higher rooting rate was obtained by higher concentration and longer soaking duration of NAA in case of hardwood cutting. Softwood cutting showed 100 ％ rooting by soaking treatment with 500 mg.L$^{-1}$ NAA for 3 min. Rooting rate of semi-hardwood cuttings was promoted by higher concentration and longer soaking with growth regulators, However, the degree of improvement was lower than soft and hardwood cutting.