• 한국미생물학회:학술대회논문집
• /
• 한국미생물학회 2006년도 International Meeting of the Microbiological Society of Korea
• /
• pp.119-123
• /
• 2006

• 한국환경농학회지
• /
• 제1권2호
• /
• pp.99-104
• /
• 1982

Hop근부(根腐)로 인(因)한 폐원(廢園)의 원인(原因)이 heptachlor잔류독성(殘留毒性)에 의한 피해(被害)인가를 구명(究明)하기 위하여 1980년(年)부터 1981년(年)까지 3개지역(個地域) 9개(個) 농가(農家) 피해포장(被害圃場)의 현장조사(現場調査)와 heptachlor약해(藥害) 시험(試驗)을 실시(實施)하였던바 그 결과(結果)를 요약(要約)하면 다음과 같다. 1) 농가포장(農家圃場)에서 발생(發生)된 hop근부(根腐) 양상(樣相)과 heptachlor 약해(藥害) 시험(試驗)에서 나타난 근부(根腐) 양상(樣相)이 일치(一致)되어 hop근부(根腐)에 의한 폐원(廢園)의 원인(原因)은 heptacholor 잔류독성(殘留毒性)의 피해(被害)임이 입증(立證)되었다. 2) 근부(根腐) 양상(樣相)은 heptachlor의 토양잔류량(土壤殘留量)이 적은 곳에서는 갈색반점(褐色斑點)으로 시작(始作)되어 부패(腐敗)되고, 잔류량(殘留量)이 많은 곳에서는 근수(根數)가 적고 비대(肥大)가 되지 않으며 갈변(褐變)하면서 고사(枯死)되었다. 3) 피해(被害) 만(蔓)의 생육(生育) 상태(狀態)는 만장(蔓長)이 짧아지고 측지수(側枝數)가 감소(減少)되며 만(蔓)의 유연성(柔軟性)이 없어 쉽게 절단(切斷)되었다. 4) Hop근부(根腐) 피해(被害)의 주물질(主物質)은 heptacholor epoxide로 추정(推定)되었으며, 토양중(土壤中) 잔류농도(殘留濃度)가 0.009 ppm에서도 피해(被害)가 심(甚)하였다. 5) heptacholor피해(被害)는 시용후(施用後) 10년(年)이 경과(經過)되어도 나타났다.

• 한국균학회지
• /
• 제45권1호
• /
• pp.74-82
• /
• 2017

꽃도라지(Eustoma grandiflorum)는 국내에서 장식용 화훼류로 널리 이용되는 절화류이다. 2015년 경기도 여주와 경남 김해 지역에서 꽃도라지가 시들고, 지제부가 잘록해지면서 위축되고, 뿌리가 썩는 증상이 나타났다. 병든 식물체는 포장이나 육묘상자에서 황화되고, 뿌리 발육이 저해되었고, 진전되면 전체적으로 황화되면서 시들고, 위축되며, 결국 2~3개월 안에 완전히 말라 죽는다. 병든 식물체 지제부에서 Fusarium균이 분리되었고, 9개 균주를 단포자 분리하여 형태적 특성을 조사한 결과, Fusarium solani로 동정되었다. 대형포자는 통통하고, 직선형이거나 약간 굽은 초승달 모양이고, 소형분생포자는 긴mono형태의 분생포자원세포에서 false head상으로 형성되었다. 후벽포자는 균사 중간 혹은 끝부분에 풍부하게 형성되었다. 이와 같은 동정 결과는 translation elongation factor 1 alpha (TEF)와 RNA polymerase II subunit (RPB2) 유전자의 염기서열 분석으로 재확인되었다. 그 결과, 분리 균주는 NCBI GenBank에 등록된 F. solani와 TEF 유전자는 99.2~99.9%, RPB2 유전자는 98.0~98.1%의 상동성을 나타내었다. 건전한 꽃도라지 유묘의 뿌리를 포자현탁액에 침지 접종하여 병원성 검정을 수행한 결과, 접종 7일 이내에 접종한 식물체에서만 병징이 관찰되었다. 따라서 이 병을 F. solani에 의한 꽃도라지 뿌리썩음병으로 명명하며, 병의 발생을 국내에서 처음으로 보고한다.

• 한국작물학회:학술대회논문집
• /
• 한국작물학회 2022년도 춘계학술대회
• /
• pp.51-51
• /
• 2022

• International Journal of Industrial Entomology and Biomaterials
• /
• 제31권2호
• /
• pp.107-114
• /
• 2015

Endophytes provide multifarious benefits such as promotion of plant growth and yield, suppression of phyto-pathogens, phosphate solubilising and fixation nitrogen. A study has been carried out to explore growth promotion and antifungal activities of endophytes of mulberry (Morus spp.). Endophytic bacteria were isolated from mulberry plants and studied their cultural, morphological characters, growth promotion as well as their antifungal activity against Rhizoctonia bataticola and Fusarium oxysporum , two mulberry root rot associated pathogens. Except two isolates, all bacteria were colourless and the colony size of eight isolates was small. The margin of five isolates was irregular and the consistency of three isolates was creamy, six isolates was slimy and one was mucoid. Texture of seven isolates was convex and others were flat. Eight isolates were gram positive and the rest Gram negative, five were cocci and others were bacilli (rod shaped). Four isolates were motile and all were catalase positive and only three isolates were oxidase positive. Spore staining was positive only for two isolates. The growth promotion study showed that there was significant difference in root length and seedling length. The antagonistic effect of the bacterial isolates was tested against R. bataticola showed significant (p <0.05) influence of the bacteria, days after inoculation and their interaction on the inhibition of fungal growth. The isolate En-7 completely inhibited the fungus followed by En-5 (66.67%). The bacterial isolates significantly (p <0.05) inhibited growth of F. oxysporum in PDA. The mean inhibition was higher (70.45%) in case of En-7 followed by En-8 (68.65%) and En-10 (66.44%). The study reveals that some endophytic bacteria associated with mulberry have growth promotion and antifungal activity and could be explored for promotion of mulberry growth and managing root rot disease.

• Journal of Microbiology and Biotechnology
• /
• 제30권7호
• /
• pp.1018-1026
• /
• 2020

Rosemary essential oil was evaluated for antifungal potentiality against six major ginseng pathogens: Sclerotinia sclerotiorum, Sclerotinia nivalis, Cylindrocarpon destructans, Alternaria panax, Botrytis cinerea, and Fusarium oxysporum. The in vitro fungicidal effects of two commonly used fungicides, namely mancozeb and fenhexamid, and the volatile organic compounds (VOCs) of Trichoderma koningiopsis T-403 on the mycelial growth were investigated. The results showed that rosemary essential oil is active against all of the pathogenic strains of ginseng root rot, whereas rosemary oil displayed high ability to inhibit the Sclerotinia spp. growth. The highest sensitivity was S. nivalis, with complete inhibition of growth at 0.1% v/v of rosemary oil, followed by Alternaria panax, which exhibited 100% inhibition at 0.3% v/v of the oil. Minimum inhibitory concentrations (MICs) of rosemary oil ranged from 0.1 % to 0.5 % (v/v). Chemical analysis using GC-MS showed the presence of thirty-two constituents within rosemary oil from R. officinals L. Camphore type is the most frequent sesquiterpene in rosemary oil composition. Mancozeb and fenhexamid showed their highest inhibition effect (45% and 30%, respectively) against A. panax. T. koningiopsis T-403 showed its highest inhibition effect (84%) against C. destructans isolate. This study may expedite the application of antifungal natural substances from rosemary and Trichoderma in the prevention and control of phytopathogenic strains in ginseng root infections.

• 한국식품영양학회지
• /
• 제9권3호
• /
• pp.275-280
• /
• 1996

For the selection of powerful antagonistic bacterium for biological control of Ewinia sp. causing vegetable soft rot, two excellent strains (54, 565) were selected from 1, 196 strains of bacteria which were isolated from rhizospere in vegetable root rot suppressive soil. Selected 2 strains were identified to be a species to Pseudomonas fluorescens S4 and pseudomonas fluorescens S65 (PS65). The highest of inhibitory activity was produced in 523 synthetic broth medium at pH 7.0 and 25t during 3 ethyl-Al-folpet, and the antibiotics such as vancomycin, perucillin and lincomycin, only PS4 was resistant to erythromycin.

• 한국식물병리학회지
• /
• 제3권3호
• /
• pp.236-238
• /
• 1987

A bacterial disease of elephant foot, Hydrosome rivieri Engl., was newly found in Taejon, Korea in August 1986. The affected plants showed symptoms of soft rot on leaf blades and petioles. Bacterial isolates from affected plants found to be pathogenic to elephant foots by antificial inoculation, producing similar symptoms with those produced naturally. The baterium was also pathogenic to carrot, Chinese cabbage, radish, potato and onion, and developed symptom of soft root on them. On the basis of bacteriological characteristics and pathogenicity, tested bacterium was identified as Erwinia carotovora subsp. carotovora and this disease was proposed to name 'Bacterial soft rot of elephant foot'.

• 식물병연구
• /
• 제24권4호
• /
• pp.339-341
• /
• 2018

Amaranth has the potential for good materials related to nutrients and health benefits. There are several diseases of amaranth such as leaf blight, damping-off, and root rot. As a causal agent of soft rot disease, Pectobacterium spp. could infect various plant species. In this study, we isolated the bacterial pathogen causing soft rot of amaranth in South Korea. In Gangneung, Gangwon province during 2017, amaranth plants showed typical soft rot symptoms such as wilting, defoliation and odd smell. To isolate pathogen, the macerated tissues of contaminated amaranth were spread onto LB agar plates and purified by a single colony subculture. One ml bacterial suspension of a representative isolate was injected to the stem of five seedlings of 2-week-old amaranth with a needle. Ten mM magnesium sulfate solution was used as a negative control. 16S rDNA gene and recA gene were sequenced and compared with the reference sequences using the BLAST. In the phylogenetic tree based on 16S rDNA gene and recA gene, GSA1 strain was grouped in Pcb.

• Journal of Ginseng Research
• /
• 제22권4호
• /
• pp.304-309
• /
• 1998

Incubation condition affecting the chlamydospore formation and isolation from mycelia and conidia of Cylindrocarpon destructanse (isolate ACY-9701), isolated from the root rot lesion of the American ginseng (Panax quinquefolium) was investigated. Chlamydospores were formed from mycilia but not from conidia on the Czapek-Dox agar without carbon or nitrogen source after 20 days incubation at 2$0^{\circ}C$. In the medium added with nitrogen and carbon sources, immatured chlamy-dospore-like cells were formed from microconidia and mycelia as well. Immatured chlamydospore-like cells were formed from mycelia as well as microconidia In corn, kidney bean, and pea root extracts after 20 days incubation at 20"C, while typical chlamydospores were formed from both of them in the root extract of Panax quinquefolium. The 3.6 log chlamydospore/mm" was converted from microconidia in the medium, which was equal to 2.5% conidia formed. Under the light condition (251.1 pmol/m" sec, 12 hrs dark and light cycle), 4.2 log/mm" of chlamydospores were converted from interracially or terminal cells of macroconidia, which was 4.0% of macroconidia produced on Potato dextrose agar (PDA). When mycelia and microconidia were stored at -7$0^{\circ}C$ for 32 days and incubated on PDA after thawing at room temperature to isolate chlamydospores from them, microconidia and mycelia were still alive. Meanwhile, microconidial lysis was found after heating them at 32$^{\circ}C$ for 7 days, but the chlamydospores converted from macroconidia were not lysed up to 13 days at 32"C. to 13 days at 32"C.ot;C.