• 제목/요약/키워드: fungicide activity

검색결과 171건 처리시간 0.018초

Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

  • Bae, Sooil;Kim, Sang Gyu;Kim, Young Ho
    • The Plant Pathology Journal
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    • 제29권1호
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    • pp.42-51
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    • 2013
  • One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

Benzaldehyde as a new class plant growth regulator on Brassica campestris

  • Choi, Geun-Hyoung;Ro, Jin-Ho;Park, Byoung-Jun;Lee, Deuk-Yeong;Cheong, Mi-Sun;Lee, Dong-Yeol;Seo, Woo-Duck;Kim, Jin Hyo
    • Journal of Applied Biological Chemistry
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    • 제59권2호
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    • pp.159-164
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    • 2016
  • Plant growth regulator is an essential pesticide to date while the available active ingredient is not well understood unlike fungicide, insecticide and herbicide. This study was aimed to evaluate a new chemical class of plant growth regulator, and the total of 92 benzene derivatives were screened for their germination and early stage of the root growth regulation on Brassica campestris. Thirty benzaldehydes, nine acids, one amide, and one ester showed potent root growth inhibitory activity (>70 % inhibition) while only salicylaldehyde showed potent germination inhibition ($IC_{50}=81.2mg/L$) suggesting that benzaldehyde was a key module candidate for the growth inhibition. Benzaldehydes were further evaluated for root growth inhibition. 2,3-Dihydroxybenzaldehyde and salicylaldehyde showed $IC_{50}$ values of 8.0 and 83.9 mg/L, respectively. On the other hand, salicylaldehyde, and 2,4,5-trihydroxybenzaldehyde were found to have root growth promotion effects less than 10 mg/L. This result suggests that the benzaldehyde is a new class candidate for plant growth regulator.

The Secondary Effects of Pencycuron on the Formation of Giant Protoplasts and the Lipid Peroxidation of Rhizoctonia solani AG4

  • Kim, Heung-Tae;Isamu Yamaguchi;Cho, Kwang-Yun
    • The Plant Pathology Journal
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    • 제17권1호
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    • pp.36-39
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    • 2001
  • The secondary effects of pencycuron on cell membrane of Rhizoctonia solani AG4 were investigated by the observation of giant protoplast formation and lipid peroxidation. Compared to protoplasts of R. solani R-C (sensitive strain) and Rh-131 (non-sensitive strain) increased in their size by 2.0-3.5 times 12 h after incubation in potato-dextrose broth containing novozyme (7 mg/$m\ell$) and $\beta$-glucuronidase ($60\mu\textrm{g}/$\textrm{ml}) with 0.6 M mannitol (pH 5.2). The increase of protoplast size in R-C was slightly inhibited from $13.8\textrm{mg}/\textrm{ml}$ without pencycuron to 10.3 ${\mu}{\textrm}{m}$ with 1.0$\mu\textrm{g}$/$m\ell$ of pencycuron. However, the size of giant protoplast of Rh-131 was not affected by the pencycuron treatment. Both strains R-C and Rh-131 did not exhibit the lipid peroxidation 12 h after the application of 1.0 $\mu\textrm{g}$/$m\ell$ pencycuron. The remarkable peroxidation of membrane lipid was observed only in R-C 24 h after pencycuron application, but not in Rh-131. Althought the inhibition of giant protoplast formation and the membrane lipid peroxidation were observed only in the sensitive strain R-C by pencycuron, it is difficult to conclude that these are the primary mechanism of pencycuron. The mild activity of pencycuron on the inhibition of giant protoplast formation and late membrane lipid peroxidation in the fungicide-sensitive strain did not noincid with the dramatic activity of pencycuron in R. solani. Therefore, our results suggest that inhibition of giant protoplast formation and membrane lipid peroxidation is the secondary effect of pencycuron.

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Antifungal Activity of Green and Chemically Synthesized ZnO Nanoparticles against Alternaria citri, the Causal Agent Citrus Black Rot

  • Hazem S. Elshafie;Ali Osman;Mahmoud M El-Saber;Ippolito Camele ;Entsar Abbas
    • The Plant Pathology Journal
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    • 제39권3호
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    • pp.265-274
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    • 2023
  • Citrus black rot is a serious disease of citrus plants caused by Alternaria citri. The current study aimed to synthesize zinc oxide nanoparticles (ZnO-NPs) by chemically or green method and investigate their antifungal activity against A. citri. The sizes of synthesized as measured by transmission electron microscope of ZnO-NPs were 88 and 65 nm for chemical and green methods, respectively. The studied prepared ZnO-NPs were applied, in vitro and in situ, at different concentrations (500, 1,000, and 2,000 ㎍/ml) in post-harvest treatment on navel orange fruits to verify the possible control effect against A. citri. Results of in vitro assay demonstrated that, at concentration 2,000 ㎍/ml, the green ZnO-NPs was able to inhibit about 61% of the fungal growth followed by 52% of chemical ZnO-NPs. In addition, scanning electron microscopy of A. citri treated in vitro with green ZnO-NPs showed swelling and deformation of conidia. Results showed also that, using a chemically and green ZnO-NPs at 2,000 ㎍/ml in situ in post-harvest treatment of orange, artificially-infected with A. citri, has reduced the disease severity to 6.92% and 9.23%, respectively, compared to 23.84% of positive control (non-treated fruits) after 20 days of storage. The out findings of this study may contribute to the development of a natural, effective, and eco-friendly strategy for eradicating harmful phytopathogenic fungi.

Chemical composition, antioxidant and antifungal activities of rhizome essential oil of Kaempferia parviflora Wall. ex Baker grown in Vietnam

  • Dang-Minh-Chanh Nguyen;Thi-Hoan Luong;Tien-Chung Nghiem;Woo-Jin Jung
    • Journal of Applied Biological Chemistry
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    • 제66권
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    • pp.15-22
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    • 2023
  • The aim of the present study was to evaluate the chemical composition and antioxidative activity of rhizome essential oil of Kaempferia parviflora Wall. ex Baker. The essential oil extracted by hydrodistillation was chemically profiled by GC/MS analysis. The antioxidative activity was determined and evaluated spectroscopically by the 2,2-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging assays. According to the results, the major essential oil components were camphene (18.03%), β-pinene (14.25%), a-pinene (12.38%), endo-borneol (10.23%), β-copaene (8.38%), and linalool (8.20%). K. parviflora rhizome oil possessed antioxidant potential, exhibiting DPPH and ABTS radical scavenging activities as high as 80.90 and 94.04%, respectively, at a concentration of 10 mg/mL. The corresponding IC50 values were 0.451±0.051 and 0.527±0.022 mg/mL, respectively (IC50 values for ascorbic acid, as the standard, were 0.209±0.016 and 0.245±0.022 mg/mL, respectively). The mycelium of F. oxysporum was distorted and collapsed when treated with 0.5 mg/mL of the EO of K. parviflora rhizome for 3 days treatment, which may provide an important information for exploring the metabolism of the fungicide K. parviflora rhizome and its derived compounds against F. oxysporum. This study provides the chemical properties of the essential oil of K. parviflora rhizome grown in Vietnam and their potential antioxidant and antifungal activities.

식물근권세균 처리에 의한 감귤 검은점무늬병에 대한 방제 효과 (Suppression of Citrus Melanose on the Leaves Treated with Rhizobacterial Strains after Inoculation with Diaporthe citri)

  • 고윤정;강소영;전용철
    • 식물병연구
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    • 제18권4호
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    • pp.331-337
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    • 2012
  • 감귤 검은점무늬병은 감귤 재배에 있어서 매우 중요한 병으로 감귤의 상품 가치를 떨어뜨리고 경제적 손실을 유발한다. 다른 감귤병과 마찬가지로 감귤 검은점무늬병 방제에는 주로 화학 농약이 사용된다. 최근 농약의 부작용 때문에 농약을 대체할 수 있는 방제 수단이 절실히 요구되고 있다. 본 연구에서는 감귤 검은점무늬병균 Diaporthe citri에 항균효과가 있는 식물근권세균 TRH423-3, MRL408-3, THJ609-3, TRH415-2을 선발하였다. 이들 세균의 감귤 검은점무늬병에 방제 효과가 있는지 알아보기 위해 감귤 잎에 전 접종한 후 감귤 검은점무늬병균을 접종하였다. 선발된 모든 식물근권세균이 감귤 검은점무늬병에 대해 방제 효과를 나타내었고 방제 정도는 식물근권세균의 균주에 따라 차이가 있었다. 감귤 검은점무늬병균을 접종한 후 추가로 식물근권세균을 접종하였더니 모든 처리구에서 방제 효과가 증진되었다. 한편, 식물근권세균 rDNA의 internal transcript spaces 염기서열을 분석한 결과 MRL408-3와 TRH423-3은 Burkholderia gladioli로, TRH415-2은 Pseudomons fluorescens로 그리고 THJ609-3은 Pseudomonas pudia로 동정되었다. 이들 선발된 식물근권세균은 화학적 방제 수단의 적용이 제한된 친환경 감귤 재배지에서 가치 있게 사용될 수 있을 것으로 판단된다.

삼불화메틸기가 포함된 디히드로-1,4-옥사티인 카르복스아닐리드 유도체의 합성과 살균 활성 (Synthesis of Trifluoromethylated Dihydro-1,4-oxathiin Carboxanilides and Their Fungicidal Activity)

  • 남기달;김진철;조광연;한호규
    • Applied Biological Chemistry
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    • 제44권3호
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    • pp.191-196
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    • 2001
  • 새로운 살균제 농약 개발을 목적으로 삼불화메틸기 디히드로-1,4-옥사티인기가 포함된 ${\alpha},{\beta}$-불포화 카르복스아미드 유도체 5를 합성하였다. 삼불화 ${\beta}$케토에스테르 유도체 6을 염화한 다음 1,2-메르캡토에탄을과 반응시켜 중간체 1,4-옥사티안 유도체 11을 얻었다. 중간체 11의 정제없이 히드록시기를 염소로 치환한 다음 중간체 10을거쳐 트리에틸 존재하에서 탈염화하여 삼불화메틸기가 포함된 디히드로-1,4-옥사티인 에틸에스테르 9를 합성하였다. 에스테르 9를 가수분해하여 생성된 카르복실산 12의 히드록시기를 염소로 치환하여 활성화한 다음 여러 가지 아민 유도체와 반응시켜 삼불화메틸기가 포함된 디히드로-1,4-옥사티인 카르복스아미드 유도체 5를 합성하였다. 합성된 화합물을 대표적인 6종의 식물병원균, 벼 도열병, 벼 잎집무의마름병, 오이 잿빛곰팡이병, 토마토 역병, 밀 붉은 녹병, 그리고 보리 흰가루병 등에 대한 in vivo 항균력을 시험하였다. 그 결과, 페닐기의 meta 위치에 이소프로폭시기 또는 이소프로필기가 치환된 화합물이 벼 잎집무의마름병과 밀 붉은녹병에 대한 강한 항균력을 나타냈다.

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식물근권세균을 처리한 감귤 잎에서 주사전자현미경을 통한 감귤 더뎅이병균의 생장 억제 관찰 (Observation of Growth Inhibition of Elsinoe fawcettii on Satsuma Mandarin Leaves Pre-treated with Rhizobacterial Strains by a Scanning Electron Microscope)

  • 박재신;송민아;전용철
    • 식물병연구
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    • 제22권1호
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    • pp.1-8
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    • 2016
  • 감귤 더뎅이병을 일으키는 E. fawcettii에 항균효과가 있는 식물근권세균 B. gladioli MRL408-3, TRH423-3, P. fluorescens THJ609-3, TRH415-2에 의해 감귤 더뎅이병이 감소하였다. 이들 식물근권세균을 전 처리한 Satsuma mandarin 감귤 잎에 감귤 더뎅이병균을 접종한 후 주사전자현미경을 이용하여 관찰하였다. 식물근권세균을 전 처리한 잎에서 무처리한 잎에 비해 감귤 더뎅이병의 병반수가 감소되었다. 특히 B. gladioli MRL408-3 균주를 전 처리한 식물에서 감귤 더뎅이병의 병반수가 뚜렷하게 억제되었다. 주사전자현미경을 통해 관찰 결과 식물근권세균을 전 처리한 감귤 잎 표면에서 병원균의 발아율과 발아관의 길이가 감소되는 것을 확인하였다. 시판 농약인 imibenconazole을 처리한 잎에서 감귤 더뎅이병균의 성장이 가장 뚜렷하게 억제되었는데, 이는 병반수가 가장 적게 형성된 것과 상통한다. 이들 결과를 통하여 식물근권세균에 의해 감귤 잎 표면에서 감귤 더뎅이병균의 발아와 생장이 억제되고 그 결과 감귤 더뎅이병의 발생이 감소되는 것으로 판단된다.

Trifluoromethylated Dihydro-1,4-dithiin carboxanilide 유도체의 합성 및 살균활성 (Synthesis of trifluoromethylated dihydro-1,4-dithiin carboxamides and their antifungal activities)

  • 한호규;남기달;장기혁;이선우;조광연
    • 농약과학회지
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    • 제5권2호
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    • pp.26-32
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    • 2001
  • 새로운 농약살균제의 개발을 목적으로 trifluoromethyl기 dihydro-1,4-dithiin기 포함된 ${\alpha},{\beta}$-불포화 carboxamide 유도체 12를 합성하였다. trifluoromethylated ${\beta}$-ketoester 유도체 4를 염화한 다음 1,2-ethandithiol과 반응시켜 중간체 1,4-dithiane 유도체 9를 얻었다. 중간체 9의 정제없이 hydroxy기를 염소로 치환하여 생성된 중간체 8을 triethylamine 존재하에서 탈염화하여 trifluoromethyl기가 포함된 dihydro-1,4-dithiin ethyl ester 7을 합성하였다. Ester 7을 가수분해하여 생성된 carboxylic acid 10의 hydroxy를 염소로 치환하여 활성화한 다음 여러 가지 amine 유도체와 반응시켜 trifluoromethyl기가 포함된 dihydro-1,4-dithiin carboxamide 유도체 12를 합성하였다. 합성된 화합물을 대표적이 6종의 식물병원균, 벼 도열병원균, 벼 잎집무늬마름병원균, 오이 잿빛곰팡이병원균, 토마토 역병원균, 밀붉은녹병원균, 보리 흰가루병원균 등에 대한 항균력을 시험 (in vivo) 하였다. 그 결과, 대부분의 화합물이 미약한 항균을 나타냈다. 페닐기의 meta 위치에 isopropy기가 치환된 화합물 12h는 250 ppm에서 밀 붉은녹병원균에 대한 항균력 (99%)을 나타냈다.

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벼 기계이앙용 어린모 최소 육묘기간 (Minimum Raising Duration of Infant Rice Seedling for Machine Transplanting)

  • 김제규;이문희;오윤진
    • 한국작물학회지
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    • 제37권1호
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    • pp.59-67
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    • 1992
  • 벼 기계이앙을 위한 어린모 육묘에 이앙 가능한 최단기 육묘일수와 맷트형성기간을 구명하기 위하여 육묘온도와 깔판재료를 달리하여 그 효과를 조사하였던 바 다음과 같은 결과를 얻었다. 1. 육모온도가 높을수록, 또 육묘기간이 길어질수록 어린모의 맷트형성이 양호하였으며, Metalaxyl(25% 수화제, 1,000 배액) 종자침종처리는 무처리에 비하여 맷트형성 기간이 단축되었다. 2. Metalaxyl 침종처리는 무처리에 비하여 어린모의 초장신장 효과가 있었고, 경엽중과 근중도 무거웠으며, 입고병과 뜸묘의 발생을 방지하였다. 3. 어린모의 맷트형성 촉진 보조재로서 흡수지깔판(키친타올 1컵)의 효과가 인정되었으며, 'Metalaxyl 침종+비닐+흡수지'처리는 다른 처리에 비하여 맷트형성 기간을 1~2일 단축시켰다. 4. 어린모의 최소 육묘일수는 파종 후 5일이였다. 육묘조건은 종자를 Metalaxyl 1,000배액에 24시간 침종한 후 비닐+흡수지 깔판에 파종하여 30/2$0^{\circ}C$(획 / 야) 온도에서 육묘한다. 5. 일반농가 비닐하우스에서 어린모 육묘시(중부지방)에는 5월의 하우스내 온도를 야간 11~16$^{\circ}C$, 획간 28~32$^{\circ}C$ 정도로 볼 때, 산파상자를 사용할 경우에는 'Metalaxyl 침종+비닐깔판'처리로, 또 어린모 전용 육묘상자를 사용할 경우에는 'Metalaxyl 침종'처리로 육묘하면 파종 후 6일에 안전 이앙이 가능한 것으로 판단된다.

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