• 한국응용곤충학회지
• /
• 제5_6권
• /
• pp.1-7
• /
• 1968

본 연구는 오동나무천구소병 바이러스의 매개충을 구명하기 위하여 착수했으며, 결과는 다음과 같다. 1) 오동나무천구소병의 이병수에 모여드는 흡수성곤충 중에서 가장 발생이 많았던 곤충은 담배장님노린제며 난, 약충, 성충이 8월 중순부터 10월 하순까지 발생하였다. 2) 담배장님노린재가 오동나무천구소병 바이러스의 매개곤충임이 구명되었다. 3) 담배장님노린재에 의하여 오동나무천구소병 바이러스를 접종한 결과 오동나무유식물에서는 접종 후 20일만에 발병을 보았고 접종 40일만에 오통나무천구소병 특유의 병징이 발현되었다. 4) 접종실험을 통해서 확인된 오동나무천구소병 바이러스의 기주식물은 오동나무 이외에 금잔화 및 나팔꽃이며, 일년감$\cdot$당근$\cdot$과꽃$\cdot$ 백일흥$\cdot$코스므스$\cdot$대두$\cdot$질경이 등에서는 충접종 후 2개월까지도 뚜렷한 발병을 확인할 수 없었다. 5) 금잔화와 나팔꽃은 발병까지의 잠복기간이 짧고 병징발현이 뚜렷한 점으로 미뤄 오동나무천구소병 바이러스의 유망한 검정식물로 생각된다.

• The Plant Pathology Journal
• /
• 제18권3호
• /
• pp.109-114
• /
• 2002

To evaluate the phylogenetic and taxonomic status of the phytoplasmas associated with water dropwort (Oenanthe javanica DC) disease in Korea and Japan, their 16S rDNA was analyzed. DNAs extracted from water dropworts collected in Korea (Kyongnam province) and Japan (Chiba prefecture) affected by witches' broom and yellows were subjected to PCR using phytoplasma-specific primers, which amplified a 1.4-kbp fragment that included the 16S rDNA. Phytoplasmas were characterized by RFLP analysis using AluI, HaeIII, HhaI, KpnI, MseI, and RsaI restriction enzymes and by sequence analysis of the PCR products. The mater dropwort witches'broom (WDWB) and water dropwort yellows (WDY) 16S rDNA sequences were identical and closely related to onion yellows (OY, 99.9% identity), which belong to the aster yellows (AY) 16S-subgroup. However, the KpnI RFLP analyses clearly distinguished the WDY and WDWB phytoplasmas from the OY phytoplasma. The phylogenetic analysis based on 16S rDNA showed that WDWE and WDY phytoplasmas are members of a relatively homogeneous group that evolved from a common ancestor.

• Journal of Microbiology and Biotechnology
• /
• 제23권8호
• /
• pp.1047-1054
• /
• 2013

Witches' broom of lime is a disease caused by Candidatus Phytoplasma aurantifolia, which represents the most significant global threat to the production of lime trees (Citrus aurantifolia). Conventional disease management strategies have shown little success, and new approaches based on genetic engineering need to be considered. The expression of recombinant antibodies and fragments thereof in plant cells is a powerful approach that can be used to suppress plant pathogens. We have developed a single-chain variable fragment antibody (scFvIMP6) against the immunodominant membrane protein (IMP) of witches' broom phytoplasma and expressed it in different plant cell compartments. We isolated scFvIMP6 from a naïve scFv phage display library and expressed it in bacteria to demonstrate its binding activity against both recombinant IMP and intact phytoplasma cells. The expression of scFvIMP6 in plants was evaluated by transferring the scFvIMP6 cDNA to plant expression vectors featuring constitutive or phloem specific promoters in cassettes with or without secretion signals, therefore causing the protein to accumulate either in the cytosol or apoplast. All constructs were transiently expressed in Nicotiana benthamiana by agroinfiltration, and antibodies of the anticipated size were detected by immunoblotting. Plant-derived scFvIMP6 was purified by affinity chromatography, and specific binding to recombinant IMP was demonstrated by enzyme-linked immunosorbent assay. Our results indicate that scFvIMP6 binds with high activity and can be used for the detection of Ca. Phytoplasma aurantifolia and is also a suitable candidate for stable expression in lime trees to suppress witches' broom of lime.

• 한국응용곤충학회지
• /
• 제15권3호
• /
• pp.107-110
• /
• 1976

oxytetracycline HCI의 대추나무 비짜루병 방제효과를 구명할 목적으로 병든 대추나무(15-20년생, 흉고직경 20cm 내외)에 oxytetracycline HCI의 1,000 p.p.m. 수용액을 1회에 500ml씩 시기별로 각각 1회(4월), 2회(4월, 7월), 30(4월, 6월, 8월) 그리고 대추 수확후 1회구(10월)로 나누어 수간에 주입하여 다음과 같은 결과를 얻었다. 1. 수간주입당년에 있어서는 시기별 주입회수에 관계없이 1회 이상의 수간주입으로 비짜루병징이 완전히 억제되고, 정상엽이 자라나면서 개화결실하였다. 2. 2회이상 주입한 나무와 10월에 1회주입한 나무에서는 이듬해 가을까지도 병징억제효과가 지속되었으나 4월에 1회 주입한 나무에서는 이듬해에 부분적으로 경미한 병징이 나타나기 시작했다. 3. oxytetracycline HCI에 의한 병징억제효과는 수간주입부위의 윗쪽에서만 나타났으며, 그 이하부위와 약액이 주입되지 않은 측지에서는 병징이 억제되지 않았다. 4. oxytetracycline HCI의 5.000 p.p.m. 수용액을 주당 30ml씩 주입하였을 때는 전혀 병징이 억제되지 않았다.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
• /
• pp.73.2-73
• /
• 2003

Typical whiches broom symptoms caused by phytoplasma were observed in Ash (Fraxinus rhynchophylla Hence) in Korea. The symptoms were showing abnormally small leaves, short internodes, and proliferation of shoots. Fluorescence and electron microscopy of leaf midribs revealed phytoplasma positive DAPI fluorescence and numerous phytoplasma bodies localized in the phloem sieve tubes. Phytoplasma DNA of 1.8 Kb was detected consistently from all symptomatic samples by the amplification of phytoplasma DNA with the phytoplasma specific primer pair Pl/P7. But no phytoplasma DNA was detected in healthy ash seedlings. Based on sequence analyses of an amplified region, this phytoplasma is closely related to Eqilodium phyllody, Mulberry dwarf, and Aster yellows phytoplasmas with the homology of 99.95 ％, 99.79 ％ and 99.78 ％, respectively, This phylogenetic analyses indicate that ash witches broom phytoplasma but is evidently distinct from the ash yellows group 16SrⅦ and should be classified into the Aster yellows group 16SrⅥ.

• 농업생명과학연구
• /
• 제43권3호
• /
• pp.1-6
• /
• 2009

빗자루병에 의하여 심각하게 이병된 제주도 5.16도로의 왕벚나무 가로수들에 대하여 피해 상황과 이병 발병 원인을 생태적으로 밝히고 그에 따른 방제 대책을 마련키 위하여 본 연구를 수행하였다. 왕벚나무 가로수 중 45년생 이상의 노거수들은 거의 모두가 심각한 정도의 빗자루병에 감염되었으며, 30년생 역시 모든 나무들이 감염되었으나 중간 정도의 발병 반응을 보이고 있었다. 그러나 수령이 23년생 미만의 왕벚나무들은 병징을 찾아볼 수 없는 건전주로 생장하고 있었다. 3년 주기로 전정 작업을 실시한 제주대학교 입구에 식재된 왕벚나무에서는 도로변 남쪽면의 나무들이 북쪽면에 비해 병 발생이 심하고 생육 또한 저조하였다. 병 발생이 심각한 산천단으로부터 견월악까지의 횡단로 좌우 인근 30m내에 자생하는 벚나무들은 수령에 따라 차이는 있지만 병 발생이 경미하였다.

• Journal of Microbiology and Biotechnology
• /
• 제21권1호
• /
• pp.81-88
• /
• 2011

The anti-phytoplasma activities of surfactin (derived from Iranian native Bacillus subtilis isolates) and tetracycline towards Candidatus "Phytoplasma aurantifolia", the agent of lime Witches' broom disease, were investigated. HPLC was used to quantify the surfactin production in four previously characterized native surfactin-producing strains, and the one producing the highest amount of surfactin (about 1,500 mg/l) was selected and cultivated following optimized production and extraction protocols. Different combinations of purified surfactin and commercial tetracycline were injected into artificially phytoplasmainfected Mexican lime seedlings using a syringe injection system. An absolute quantitative real-time PCR system was developed to monitor the phytoplasma population shifts in the lime phloem during 3 months following the injections. The results revealed that the injections of surfactin or tetracycline had a significant inhibitory effect on Candidatus "P. aurantifolia". However, the combined treatment with both surfactin and tetracycline (1:1) resulted in the highest inhibition due to a synergic effect, which suppressed the phytoplasma population from about $2{\times}10^5$ to less than 10 phytoplasma units/g plant tissue.

• 한국응용곤충학회지
• /
• 제4권
• /
• pp.7-10
• /
• 1965

In an experiment to evaluate the various aspects of symptom of witches' broom of jujube tree with two different kinds of scions, taken from diseased plant and stem- grafted upon sound stocks-one cut before wintering(stored in cellar), the other after wintering, it was observed that the disease rate of those cut before wintering(Nov.) was $\98\%$ whereas those cut after wintering(March) showed much lower rate, $3\%$ initially and gradually increased up to $39\%$. In another experiment of diseased bud grafted into healthy seedling, the finding made in the following year was that 14 stocks(only one of which salt union by callusing) were infected out of the given 23- in the initial stage only 4, yet gradually increased to the number of 14. The shoots from the ground portion of the diseased stock were in general more quickly subjected to the disease than the others. Under natural condition, the diseased trees develop at first seemingly the same leaves as healthy ones; it is not until the branches and loaves grow to a considerable degree that the symptom appears. Once appearing, tile disease grows and the symptom continues to appear as late as in Sept. and early Oct., causing tile plant to develop the extraordinary branches and leaves of extremely reduced size, the typical symptom of witches' broom. Such phenomenon can be observed in the experiments of the foregoing paragraphs. And the suckers and roots of diseased plant are bound to be infected, it was found out with no exception. Viewing from the results of the above experiments and observation, it is believed that the low temperature during winter causes the virus in the above-ground portion of diseased plant to diminish or inactivated, and subsequently the virus in the roots moves up or multiply in the sprouting season.

• 한국식물병리학회:학술대회논문집
• /
• 한국식물병리학회 2000년도 추계 학술발표회
• /
• pp.49.2-49
• /
• 2000

• 식물병연구
• /
• 제26권1호
• /
• pp.19-28
• /
• 2020

대추나무 빗자루병은 1950년대에 남한지역에 대발생하여 대추 재배지를 황폐화시킨 고위험 식물병이다. 최근 전국적으로 대추 재배면적이 크게 증가하고 있어 빗자루병 대발생 위험성을 사전에 파악하기 위한 기초자료를 얻고자 2017년과 2019년에 걸쳐 보은 지역의 대추 과원에서 병조사를 하였다. 또한, 빗자루병 조기 진단에 활용할 수 있는 다양한 병징을 찾아내고, 성보싸이클린수화제(OTC, 옥시테트라사이클린칼슘알킬트리메틸암모늄 수화제, 유효성분 17%)의 수간주사 방제효과 증진을 위한 연구를 수행하였다. 그 결과 현재까지 충북 보은 지역의 대추나무 빗자루병 발병률(이병주율)은 매우 낮았으나, 발생 지역과 발생 농가를 중심으로 점차 의미 있게 증가하고 있었다. OTC 방제시험 결과 처리 시기는 대추나무 생육 초기가 가장 효과적이었다. 그러나 발병이 심한 나무에서는 수간주사 후 당해 연도에도 같은 나무의 다른 건전한 가지에서 병징이 발현되었다. 6월에 1차 수간주사를 한 처리에서 2차 수간주사는 5개월 후보다 한 달 후에 하였을 때 방제효과가 더 좋았다. 이러한 결과는 조기 병징을 활용한 진단과 이를 근거로 한 조기 방제가 빗자루병 피해를 사전에 차단하고 병 방제효과를 높이는 데 매우 효과적일 수 있음을 시사한다.