• 식물병연구
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• 제22권2호
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• pp.116-121
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• 2016

In 2015, stem blight of Rubus crataegifolius was observed in Pohang, Korea. The symptoms began as dark red spots in the stem, which led to stem blight, then leaf blight, and eventually resulted in death. A fungal isolate was obtained from a symptomatic stem and incubated on a potato dextrose agar plate. The isolated fungus produced white, cloudy mycelia turned black in 3 days. Based on the morphological characteristics, the causal fungus was assumed to be Botryosphaeria sp. A pathogenicity test was conducted according to Koch's postulates. To identify the causal agent, the combined sequence of the internal transcribed spacer, ${\beta}$-tubulin, and translation elongation factor $1{\alpha}$ genes were used for phylogenetic analysis. Approximately 1,200 bp of the combined sequence clearly suggested that the isolated pathogen was Botryosphaeria parva. This is the first report on stem blight in R. crataegifolius caused by B. parva in Korea.

• 식물병연구
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• 제24권2호
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• pp.138-144
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• 2018

In December 2016, stem rot symptoms were observed on Persian buttercup (Ranunculus asiaticus) plants in Chilgok, Gyeongbuk, Korea. In the early stage of the disease, several black spots appeared on the stem of infected plants. As the disease progressed, the infected stem cleaved and wilted. The causal agent was isolated from a lesion and incubated on Reasoner's 2A (R2A) agar at $25^{\circ}C$. Total genomic DNA was extracted for phylogenetic analysis. Based on the 16S rRNA gene analysis, the isolated strain was found to belong to the genus Pseudomonas. To identify the isolated bacterial strain at the species level, the nucleotide sequences of the gyrase B (gyrB) and RNA polymerase D (rpoD) genes were obtained and compared with the sequences in the GenBank database. As the result, the causal agent of the stem rot disease was identified as Pseudomonas marginalis. To determine the pathogenicity of the isolated bacterial strain, it was inoculated into the stem of healthy R. asiaticus plant, the inoculated plant showed a lesion with the same characteristics as the naturally infected plant. Based on these results, this is the first report of bacterial stem rot on R. asiaticus caused by P. marginalis in Korea.

• The Plant Pathology Journal
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• 제26권3호
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• pp.297-297
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• 2010

• 한국토양비료학회지
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• 제46권4호
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• pp.276-280
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• 2013

D. kaki and D. lotus are used as rootstocks for astringent persimmons in Korea but characteristics of their seedlings have not been determined. In this experiment, their seeds were sown in 3-L pots on April 18 and the seedlings were grown until October 24. Growth and nutrient absorption were compared at the end of the season after destructively harvesting the seedlings. Seedling growth of D. lotus was much faster than that of D. kaki in terms of total stem length, stem diameter, and number of leaves. However, chlorophyll value and specific leaf weight were higher in D. kaki than in D. lotus. Dry weight of D. lotus was 3.6- and 3.7-fold higher than that of D. kaki in above-ground parts and the root, respectively. D. kaki seedlings were characterized by higher concentrations of N, P, K, Ca, and Mg in the leaves, stem, or the root. However, total contents of the elements were 1.8- to 3.7-fold higher in a D. lotus seedling due to its greater dry weight. Since D. lotus seedlings absorbed more inorganic elements on a tree basis and grew more vigorously than D. kaki seedlings, the level of fertilization for astringent persimmons should be adjusted depending on rootstocks to maintain the trees at the optimum vigor.

• Journal of Plant Biotechnology
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• 제36권4호
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• pp.373-383
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• 2009

To set efficient transformation system in chrysanthemum, thirty-four chrysanthemum (Dendranthema grandiflorum Kitamura) varieties were collected and cultured for shoot regeneration. Five varieties, ‘Shuho-no-chikara', ‘Zinba', ‘Baekma', ‘Pink pride' and ‘Keumsu' of them were selected, because they had a high shoot regeneration efficiency. MS medium containing 1.0 mg/L NAA and BA respectively was very adequate for shoot regeneration in those varieties. MS medium with 3.0 mg/L NAA and 1.0 mg/L kinetin in ‘Shuho-no-chikara' and the medium with 0.5 mg/L NAA and 3.0 mg/L BA in ‘Keumsu' were also suitable for shoot regeneration. The most efficient callus induction and shoot regeneration were obtained on MS medium. Shoot regeneration was enhanced more than 8% on MS medium with 0.3% phytagel and 10-15 mg/L putrescine. The best cultural material for shoot regeneration was stem. When stem was used as a culture material, shoot regeneration rate was increased more than 26% and the days to shoot regeneration was shortened about 14 days.

• 한국자원식물학회:학술대회논문집
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• 한국자원식물학회 2019년도 추계학술대회
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• pp.16-16
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• 2019

The Cassava (Manihot esculenta Crantz) is a perennial woody shrub cultivated mainly in the tropics for its starchy tuberous roots. It belongs to the family Euphorbiaceae which also includes rubber (Hevea brasiliensis) and castor bean (Ricinus communis). Among tropical crops, rice, sugarcane, maize and cassava are the most important sources of calories for human consumption. Problems in the propagation of cassava are virus diseases and low rates of seed germination. Thus, a study was undertaken to develop an efficient in vitro mass propagation protocol of Manihot esculenta Crantz. Young and actively growing stem segments were excised from adult plants of cassava. Samples were cut into a 3~4 cm nodal segments with single node after sterilization, and cultivated in the different medium supplemented with various plant growth regulators for 4 weeks. For shoot multiplication, single-node stem segments, approximately 1 cm in length, were taken from in vitro derived shoots and subcultured. After 4~6 weeks, the shoot generation rate was 55.6%, the shoot number and its length were 1.0/explant and 2.3 cm in the most favorable medium composition. Our experiments confirmed that in vitro growth and multiplication of plantlets could depend on its reaction to the different medium composition, and this micropropagation techniques could be a useful system for healthy and vigorous plant production.

• 한국균학회지
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• 제36권2호
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• pp.203-205
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• 2008

2006년에서 2008년까지 진주에서 재배중인 페튜니아에서 병이 발생하였다. 병징은 줄기와 잎이 수침상으로 물러지고 썩으면서 갈색으로 변하며 시들어 말라 죽었다. 줄기, 지제부 및 토양 표면에 솜털모양의 흰색 균사체가 생기고 $1{\sim}3\;mm$ 크기의 둥근 갈색 균핵을 많이 형성하였다. PDA배지 상에서 병원균의 균사 폭은 $4{\sim}8\;{\mu}m$이며 clamp connection이 형성되었고 균사생육과 균핵형성 적온은 $30^{\circ}C$이었다. 페튜니아에서 발생한 병징과 병원균의 균학적 특징 및 병원성을 기초로 본 병을 Sclerotium rolfsii Saccardo에 의한 페튜니아 흰비단병으로 명명하고자 제안한다.

• 화훼연구
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• 제18권4호
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• pp.238-243
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• 2010

본 연구는 직삽 양액재배에 의한 '백마' 품종의 줄기공동화를 경감하고 절화품질 향상시키고자 양액 pH조정 비료종류와 에세폰 살포 효과를 알아보고자 실시하였다. 양액 pH조정 비료종류에 따른 pH 경시적 변화는 수산화칼륨 처리에서 pH 5.65에서 시작하여 큰 변화 없이 안정적으로 유지되었다. 화아분화기 이후 양액 pH조정 비료종류에 따른 절화장, 엽수, 절화중, 및 꽃잎수는 수산화칼륨 처리가 가장 좋았다. 중탄산칼륨처리는 경경이 두껍고 내벽이 두꺼워 동공의 크기와 면적이 가장 적었으나, 생육과 절화품질이 가장 좋은 수산화칼륨 처리구에서는 동공이 다소 큰 경향이었다. 화아분화기 이후 양액 pH조정에 따른 양분 흡수변화는 중탄산칼륨 처리는 전질소, 인산, 칼륨 및 칼슘의 흡수가 가장 적게 일어나 순환식 양액탱크내 잔류량이 가장 많은 반면 수산화칼륨의 경우 전질소, 인산, 칼륨 및 칼슘의 순환식 양액탱크내 잔류량이 적어 식물체내로 일정하게 흡수되도록 하여 생육 및 절화품질을 향상시킨 것으로 생각되었다. 에세폰 엽면 살포의 농도와 시기에 따른 생육은 관행(무처리)에 비해 500배 처리에서는 생육억제가, 1,000배와 2,000배 처리에서는 생육촉진 효과가 나타났다. 꽃잎수는 관행 302매에 비해 1,000배 개화 45일전 처리가 331개/송이로 가장 많게 나타났다. 에세폰 처리에 따른 줄기동공은 관행에 비해 2,000배 개화 30일전 처리가 크기 1.0 mm, 면적이 7% 정도 더 적은 것으로 나타났다. 따라서 국화 '백마' 양액 재배시 화아분화기 이후 수산화칼륨을 이용하여 양액 pH를 안정화시키고 에세폰 2,000배액을 개화 30일전 처리하여 줄기동공 크기를 감소시킴으로써 생육 및 절화품질향상을 도모할 수 있을 것으로 생각되었다.

• 식물병연구
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• 제21권1호
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• pp.36-39
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• 2015

2012년과 2013년 6월 하순 강원도 횡성과 평창의 곰취(Ligularia fischeri) 재배포장에서 포기가 서서히 시들어 말라 죽는 이상 증상이 발생하였다. 발병정도는 30-80%로 병든 식물체를 조사한 결과, 줄기가 수침상으로 물러지고 썩으면서 흰색의 곰팡이와 갈색의 작고 둥근 균핵이 관찰되었다. 병원균을 순수 분리하여 병원균의 균학적 특징을 조사한 결과, 감자한천배지에서 균총은 흰색으로 잘 자라며 갈색의 작고 둥근 균핵을 많이 형성하였다. 균핵의 크기는 1-3 mm이며, 균사의 폭은 $4-10{\mu}m$였다. 균사생육과 균핵 형성 적온은 $25-30^{\circ}C$이었으며, 균사특유의 clamp connection이 관찰되었다. 또한, 병원균의 염기서열 분석결과 695 bp로 Sclerotium rolfsii와 같은 계통군으로 확인되었으며, 99% 이상의 상동성을 보였다. 이와 같이 곰취에 발생한 병징, 병원균의 균학적 특징 및 염기서열 분석 등을 종합한 결과 S. rolfsii Saccardo로 동정되어 곰취 흰비단병으로 명명하고자 한다.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 2004년도 추계학술대회 논문집
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• pp.5-9
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• 2004

Garlic industries in Korea faced with a increasing difficulty because of the pressure of garlic importation from China is ever increasing than before. Therefore this study was conducted to produce low-cost garlics by mechanized cultivation and the results are as follows. A. By applying machinery(stem cutter and size separator, seeder, harvester) the labor was saved over 70% compare with the conventional cultivation B. Growth characteristics and yield showed no difference in mechanized and conventional cultivation of northern-type garlic. C. When scales were sown by seeder, the sowing-depth varied between 3 to 6cm and the rate of 2-plants emergence in one hole was 14.5%.