• Title/Summary/Keyword: sclerotinia rot

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Sclerotinia Shoot Rot of Grapevine (Vitis spp.) Caused by Sclerotinia sclerotiorum in Korea (Sclerotinia sclerotiorum에 의한 포도나무 균핵병 발생)

  • Park, Jong-Han;Han, Kyung-Sook;Han, You-Kyoung;Lee, Jung-Sup;Kim, Dae-Hyun;Hwang, Jeong-Hwan
    • Research in Plant Disease
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    • v.15 no.3
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    • pp.259-261
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    • 2009
  • Sclerotinia shoot rot of Grapevine(Vitis labruscana) occurred at Gapyeong and Yeongwol area from 2003 to 2005. Infected plants showed shoot blight at the one-year-old fruit bearing branches. The first visible symptom noticed was wilting and blighting of the branches. The obvious and typical initial symptom is the presence of a cottony, white, dense mat of mycelial growth on the surface of the diseased lesions. The base or stem of the infected young shoots develop a pale brown rotted area, which girdled and killed shoots. In advanced stages of the disease, stems and branches became bleached and eventually died. The isolates collected from diseased grapevine stem were identified as Sclerotinia sclerotiorum based on the morphological and cultural characteristics. The pathogenicity test revealed that Vitis vinifera(cultivar: Kyoho) was stronger than V. labruscana(cultivar: Campbell early) to the pathogen. This is the first report on sclerotinia shoot rot of grapevine in Korea.

Occurrence of Sclerotinia Rot on Cucurbitaceous Vegetable Crops in Greenhouses (온실재배 박과 채소작물에서의 균핵병 발생)

  • Kim, Wan-Gyu;Cho, Weon-Dae;Jee, Hyeong-Jin
    • The Korean Journal of Mycology
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    • v.27 no.3 s.90
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    • pp.198-205
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    • 1999
  • Cucurbitaceous vegetable crops grown in greenhouses in Korea were surveyed from 1995 to 1997. Incidence of Sclerotinia rot was as high as $30{\sim}70%$ at its maximum on Cucumis melo var. reticulatus (netted melon), Cucumis sativus (cucumber), Cucurbita moschata (pumpkin) and Cucurbita pepo (summer squash) but relatively low on Citrullus lanatus (watermelon) and Cucumis melo var. makuwa (oriental melon). Symptoms of Sclerotinia rot developed on stems of all the cucurbits, fruits of five cucurbits except C. lanatus, petioles of two Cucurbita spp. and leaves of C. moschata. A total of 126 isolates of Sclerotinia sp. were obtained from the lesions and identified as Sclerotinia sclerotiorum based on the morphological and cultural characteristics. The fungus was very frequently isolated from stems and fruits of the cucurbits but rarely from petioles and leaves. Six isolates of the fungus were pathogenic to six cucurbits tested although there was some difference in virulence among the isolates to some of the hosts. C. lanatus was the most susceptible to the isolates, whereas C. melo var. makuwa was the most resistant. C. melo var. reticulatus and C. sativus were relatively susceptible to the isolates, and C. moschata and C. pepo relatively resistant.

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The control effect of some fungicides against cucumber sclerotinia rot and the sensitivity of sclerotinia isolates to fungicides (오이 균핵병에 대한 몇 가지 살균제의 방제 효과와 살균제에 대한 균핵병균의 감수성 정도 조사)

  • Kim, Myeong-Ok;Min, Ji-Young;Choi, Woo-Bong;Kang, Beum-Kwan;Park, Sung-Woo;Choi, Gyung-Ja;Park, Chang-Sik;Cho, Kwang-Yun;Kim, Heung-Tae
    • The Korean Journal of Pesticide Science
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    • v.9 no.4
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    • pp.429-436
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    • 2005
  • As Sclerotinia sclerotiorum causing cucumber sclerotinia rot was the fastest in the mycelial growth at $25^{\circ}C$, its pathogenicity was strong at the same temperature among several temperatures. All the isolates of Sclerotinia sclerotiorum showed a strong pathogenicity against cucumber fruits, which was confirmed by a disk assay and a wound assay. A wound assay was superior to a disk assay to develop the assay system for assessing the fungicidal activity of several fungicides against Sclerotinia sclerotiorum. In a disk assay, it was very difficult to assess the fungicidal activity, because the pathogenicity of isolates used in the experiment was very strong. At 500 and $3.0{\mu}g/mL$, the activity of dichloflouanid and the mixture of carbendazim and diethofencarb against cucumber sclerotinia rot was 14.3 and 42.3%, respectively, by using a disk assay. However, at same concentration two fungicides showed the high controlling activity as 100 and 92.5%, through a wound assay in a laboratory. Also, the activity of two fungicides was good against cucumber sclerotinia rot in the greenhouse where cucumber plants were cultivated in the field, showing the control value as 91.1 and 82.9% at 100 and $825{\mu}g/mL$, respectively. All the isolates of Sclerotinia sclerotiorum from cucumber fruits sampled in the polyvinyl house were subjected to monitoring for the resistance to 7 fungicides. The $EC_{50}$ value of 7 fungicides was as follows: fenhexamid; $0.13{\mu}g/mL$, procymidon and iprodione; 0.18 and $0.24{\mu}g/mL$, carbendazim and the mixture of carbendazim and diethofencarb; 0.13과 $0.05{\mu}g/mL$, iminoctadine and dichlofluanid; 1.94 and $8.95{\mu}g/mL$. Ultimately it was not found that resistant isolates of Sclerotinia sclerotiorum were appeared in the field.

Biological control efficacy on Sclerotinia rot(Sclerotinia sclerotiorum) by the use of antifungal agent some Bacillus sp.

  • Hong, Yeon-Kyu;Lee, Bong-Choon;Shin, Dong-Beom;Hyun, Jong-Nae;Kang, Hang-Won;Park, Sung-Tae
    • Proceedings of the Korean Society of Plant Pathology Conference
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    • 2003.10a
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    • pp.106-107
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    • 2003
  • The effect of biological control agent Bacillus sp. (BAC03-3-1, BAC03-3-2, BAC02-4) on pre- and postemergence Sclerotinia rot of perilla (Perilla frutescens var. japonica) caused by Sclerotinia sclerotiorum was determined from greenhouse field trials. The ability of this antagonist to reduce germination of sclerotia of S. sclerotiorum was also evaluated. In the greenhouse, suspension of BAC03-3-1 application as root drench of perilla, which provided as little as 10$\^$7/ cells/ $m\ell$ per gram of soil, significantly increased plant stand in pathogen-infested soil over that in the untreated control. All three isolates reduced the germination of sclerotia of S. sclerotiorum in loamy sand soils in the greenhouse. In loamy sand amended with rice bran the sclerotial germination was inversely correlated (r = -0.79) with perilla stand in the greenhouse. However, a higher rate of bacterial suspension with rice bran(Ig dwt./100g soil) than that applied with bacterial suspensions only was necessary to achieve a comparable reduction in sclerotial germination. In field study, all three isolates added to soil to provide 10$\^$7/ cells/$m\ell$ per gram significantly prevented Sclerotinia rot (73-85%) after 35 days of growth. The isolate BAC02-4, BAC03-3-1 and BAC03-3-2 gave final stands of 65 to 75, 60 to 70, and 55 to 60%, respectively. The addition of rice bran(1 %) to loamy sand in the field resulted in a 10-fold increase in propagule numbers of the three isolates within 10 days of application.

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Effect of Bacillus subtilis C4 and B. cereus D8 on Plant Growth of Canola and Controlling Activity Against Soft Rot and Stem Rot (Bacillus subtilis C4와 B. cereus D8에 의한 유채의 생육증대 및 무름병과 균핵병 방제효과)

  • Lee, Jae-Eun;Lee, Seo-Hyeun;Park, Kyung-Soo;Park, Jin-Woo;Park, Kyung-Seok
    • The Korean Journal of Pesticide Science
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    • v.13 no.4
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    • pp.275-282
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    • 2009
  • The effect of two plant growth-promoting rhizobacteria (PGPR) on plant growth and systemic protection against soft rot disease and stem rot disease of canola (Brassica napus), caused by Erwinia carotovora and Sclerotinia sclerotiorum was investigated in a laboratory and a greenhouse. Selected PGPR strains C4 and D8 were treated to canola seeds by soaking. Strains C4 and D8 significantly not only increased plant height and root length about 74% and 40.3% and also reduced disease severity of soft rot disease by 80% by C4 and D8 respectively, compared to the control. Especially strain C4 showed antifungal activity against 6 fungal pathogens, S. sclerotiorum, Rhizoctonia solani, Botrytis cinerea, Fusarium oxysporum, Phytophthora capsici and Colletotrichum acutatum. In greenhouse experiment, the seed treatment of both of them increased plant height, leaf width and leaf length of canola plant to 19.5% and 24.9%, 11.3% and 15.3%, and 14.1% and 20.7% by C4 and D8, respectively, and reduced disease severity of S. sclerotiorium. These results indicate that these two PGPR strains can decrease disease severity and increased plant growth under greenhouse condition. Therefore, these two bacteria have a potential in controlling Sclerotinia stem rot of canola. These strains have to investigate under field condition to determine their role of antibiosis, induced systemic resistance and plant growth promotion on canola.

Inhibitory Effect of Paraconiothyrium minitans CM2 on Sclerotial Germination of Sclerotinia sclerotiorum and S. minor Causing Sclerotinia Rot of Lettuce (Paraconiothyrium minitans CM2의 상추균핵병균(Sclerotinia sclerotiorum, S. minor) 균핵 발아에 대한 억제 효과)

  • Lee, Sang-Yeob;Kim, Wan-Gyu;Hong, Sung-Kee;Weon, Hang-Yeon;Park, Kyung-Seok
    • The Korean Journal of Mycology
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    • v.39 no.2
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    • pp.131-135
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    • 2011
  • One fungal isolate CM2 parasitic to Sclerotinia sclerotiorum and S. minor causing Sclerotinia rot of lettuce was identified as Paraconiothyrium minitans based on its morphological and molecular characteristics. P. minitans CM2 grew best on PDA with pH 6.5 at $22^{\circ}C$ under alternating cycles of 12 hr near ultraviolet light and 12 hr darkness. Scleroria of S. sclerotiorum and S. minor treated with conidial suspension of P. minitans CM2 did not directly germinate and produced no apothecia.

Multiplex TaqMan qPCR Assay for Detection, Identification, and Quantification of Three Sclerotinia Species

  • Dong Jae Lee;Jin A Lee;Dae-Han Chae;Hwi-Seo Jang;Young-Joon Choi;Dalsoo Kim
    • Mycobiology
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    • v.50 no.5
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    • pp.382-388
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    • 2022
  • White mold (or Sclerotinia stem rot), caused by Sclerotinia species, is a major air, soil, or seed-transmitted disease affecting numerous crops and wild plants. Microscopic or culture-based methods currently available for their detection and identification are time-consuming, laborious, and often erroneous. Therefore, we developed a multiplex quantitative PCR (qPCR) assay for the discrimination, detection, and quantification of DNA collected from each of the three economically relevant Sclerotinia species, namely, S. sclerotiorum, S. minor, and S. nivalis. TaqMan primer/probe combinations specific for each Sclerotinia species were designed based on the gene sequences encoding aspartyl protease. High specificity and sensitivity of each probe were confirmed for sclerotium and soil samples, as well as pure cultures, using simplex and multiplex qPCRs. This multiplex assay could be helpful in detecting and quantifying specific species of Sclerotinia, and therefore, may be valuable for disease diagnosis, forecasting, and management.

Biocontrol Traits and Antagonistic Potential of Bacillus amyloliquefaciens Strain NJZJSB3 Against Sclerotinia sclerotiorum, a Causal Agent of Canola Stem Rot

  • Wu, Yuncheng;Yuan, Jun;Raza, Waseem;Shen, Qirong;Huang, Qiwei
    • Journal of Microbiology and Biotechnology
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    • v.24 no.10
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    • pp.1327-1336
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    • 2014
  • Bacillus amyloliquefaciens strain NJZJSB3 has shown antagonism of several phytopathogens in vitro, especially Sclerotinia sclerotiorum. Both the broth culture and cell suspension of strain NJZJSB3 could completely protect the detached leaves of canola (Brassica napus) from S. sclerotiorum infection. In pot experiments, the application of strain NJZJSB3 cell suspension ($10^8CFU/ml$) decreased the disease incidence by 83.3%, a result similar to commercially available fungicide (Dimetachlone). In order to investigate the potential biocontrol mechanisms of strain NJZJSB3, the nonvolatile antifungal compounds it produces were identified as iturin homologs using HPLC-ESI-MS. Antifungal volatile organic compounds were identified by gas chromatography-mass spectrometry. The detected volatiles toluene, phenol, and benzothiazole showed antifungal effects against S. sclerotiorum in chemical control experiments. Strain NJZJSB3 also produced biofilm, siderophores and cell-wall-degrading enzymes (protease and ${\beta}$-1,3-glucanase). These results suggest that strain NJZJSB3 can be a tremendous potential agent for the biological control of sclerotinia stem rot.