• Research in Plant Disease
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• v.15 no.3
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• pp.217-221
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• 2009

Fludioxonil is derived from the antifungal compound pyrrolnitrin produced by Pseudomonas pyrrocinia and classified as a reduced-risk fungicide by the US EPA. The efficacy of fludioxonil for the control of lettuce gray mold caused by Botrytis cinerea was evaluated under several conditions such as growth stages of host, inoculum concentrations, and amounts of potato dextrose broth (PDB) included in spore suspension of B. cinerea. At 4-leaf stage of lettuce plants, fludioxonil applied at 2 ${\mu}g$/ml was more effective for the control of gray mold than at 5- and 6-leaf stages. However, fludioxonil at more than 10 ${\mu}g$/ml provided similar control activity in all growth stages of lettuce tested. The fungicide (10 and 50 ${\mu}g$/ml) also gave excellent control of gray mold on lettuce seedlings inoculated with spore suspensions of B. cinerea ($2.5{\times}10^5$ to $2{\times}10^6$ spores/ml). But, control efficacy of fludioxonil (2 ${\mu}g$/ml) was negatively correlated with inoculum concentration. Addition of PDB in spore suspension of B. cinerea resulted in higher disease severity than non-treated control. By inoculating spore suspension including 0.5% PDB, the fungicide gave the most control activity on the disease, followed by 1% and 2% PDB. The results suggest that fludioxonil has potential to control gray mold of lettuce, but the fungicide at a concentration having moderate activity may represent low control efficacy on the disease under some conditions.

• Mycobiology
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• v.41 no.2
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• pp.108-111
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• 2013

The use of a microorganism, or its secretions, to prevent plant disease offers an attractive alternative or supplement to synthetic fungicides for the management of plant disease without the negative effects of chemical control mechanisms. During a screening for microorganisms with the potential to be used as microbial fungicides, Bacillus sp. BS061 was isolated from a plant leaf. The strain BS061 potently inhibited the mycelial growth of Botrytis cinerea, and significantly reduced disease incidence of powdery mildew in cucumber and strawberry. We also found that the culture filtrate of BS061 inhibited the mycelial growth of various plant pathogens.

• Research in Plant Disease
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• v.12 no.1
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• pp.58-61
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• 2006

Ggray mold caused by Botrytis cinerea occurred on Balsam pear (Momordica charantia) at Daesan-myon, Changwon city, Gyeongnam province in Korea from 2004 to 2006. The disease symptoms usually started with water-soaking lesions on the fruits tip and stem, and then the infected plants became withered and eventually died. The conidia of the pathogen appeared on the surface of fruit and stem of infected plants. The conidia were one celled and mostly ellipsoid or ovoid in shape and were light gray in color, The conidia were $6{\sim}20X4{\sim}12{\mu}m$ in size and conidiophores were $14{\sim}30{\mu}m$ in length. The sclerotia formed abundantly on potato-dextrose agar 18 days after incubation. The optimum temperature for sclerotial formation was $20^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch,s postulates. The causal organism was identified as Botrytis cinerea Persoon: Fries based on the mycological characteristics. This is the first report on gray mold of M. charantia caused by B. cinerea in Korea.

• Research in Plant Disease
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• v.10 no.2
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• pp.117-120
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• 2004

In April of 2003, the gray mold disease occurred severely on statice (Limonium shinuatum Mill. cv. Sophia) grown in the commerical farms in Seosang-myon, Hamyang-gun, Gyeongnam Province, Korea, 2003. The infected plants were started with water-soaking lesions in the stems, the leaves and the flowers became withered and discolored to gray or dark from the tip then gradually expanded to die. The conidia and mycelia of the pathogen appeared on flowers, leaves, calyx and flower stalk. The conidia were gray, I-celled, mostly ellipsoid or ovoid in shape and were 8∼20 x 6∼14 ${\mu}{\textrm}{m}$ in size. Conidiophores were 14∼34 ${\mu}{\textrm}{m}$ in size. The sclerotia were formed abundantly on potato-dextrose agar. The optimum temperature for sclerotial formation was 2$0^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulate. The causal organism was identified as Botrytis cinerea Persoon: Fries based on mycological characteristics. This is the first report on gray mold of statice (Limonium shinuatum) caused by Botrytis cinerea in Korea.

• The Plant Pathology Journal
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• v.18 no.1
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• pp.36-42
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• 2002

Resistance of perilla varieties to Botrytis cinerea LVF12 was evaluated, while antagonistic bacteria were selected and tested for their efficacy towards biological control of gray mold rot caused by B. cinerea. Among 11 perilla varieties tested for disease resistance, Milyang variety showed some degree of resistance, while the rest of varieties showed no resistance. Among 250 bacterial isolates collected from perilla loaves and rhizosphere of perilla plants, six isolates showed high levels of inhibitory effect on mycelial growth and conidial germination of B. cinerea in in vitro test. Using the pot test in growth chambers these isolates showed high levels of disease suppression, with Nl isolate showing 95.3% of control value and N4 isolate showing 90.8% of control value. Further test was performed to evaluate the two isolates ability for disease prevention and/or disease therapy, and results showed almost 100% of control vague. Isolates Nl and N4 were identified as Bacillus licheniformis and 5. megatepium, respectively, according to Bergey's manual, API 20E and 50CHB test kit, and Transmission electron microscope.

• Research in Plant Disease
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• v.7 no.3
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• pp.134-139
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• 2001

Effects of tomato-juice and KH$_2$PO$_4$ as exogenous nutrients on the infection of Botrytis cinerea LVF12 and pathogenicity to tomato were investigated. B. cinerea LVF12, which was previously reported as a casual agent of the gray mold rot of perilla, was used for pathogenesis on tomato leaves. No infection was induced, and no lesion developed on tomato leaves by the conidial suspension of LVF12 when the inoculum was prepared in sterilized water. However, when the conidial suspensions of LVF12 added with various concentrations and conditions of tomato-juice were inoculated on whole tomato plants, the disease was induced readily, Among them, 20% tomato juice with 0.1M KH$_2$PO$_4$ appeared to be the most suitable nutrient to promote high disease incidence on tomato. For the pathogenicity test according to the growing stage of tomato, the mature leaves were more susceptible than seedlings. Symptoms on the infected plants were initial small gray spots at the inoculated area. Later the whole leaves, petioles and stems became gray and eventually fell off, Under high humidity conditions, the diseased leaves and stems were covered with gray hyphae and conidia. All symptoms of infected plants were identical to those in the field conditions.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.399-410
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• 2006

This study was carried out to identity the effects of antifungal bacteria isolated from the soil grown kiwi fruit plants on the growth inhibition of Botrytis cinerea causing gray mold in kiwi fruit plants in the southern districts of Jeonnam. Two hundred and fifty antagonistic microorganisms were isolated and examined into the antifungal activity against Botrytis cinerea. We screened and isolated four bacterial strains which strongly inhibited Botrytis cinerea from the soil grown kiwi fruit plants. And the best antifungal bacterial strain which called CHO 163 was finally selected. Antagonistic microorganism CHO 163 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. CHO 163 showed 86.9% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. CHO 163 showed almost all of antagonistic activity against Botrytis cinerea. And we also confirmed that in vitro the treatment of Bacillus sp. CHO 163 cultured by SD+B+P broth efficiently controled the growth of Botrytis cinerea causing gray mold in kiwi fruit plants.

• The Korean Journal of Mycology
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• v.34 no.1
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• pp.59-61
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• 2006

Gray mold caused by Botrytis cinerea on Agastache rugosa was occurred at a field of Jinju from 2003 to 2005. The disease symptoms started with water-soaked lesions in the leaves and stem, then these infected lesions became withered, discolored, rotten and died eventually. The fungal pathogen was isolated from the lesions. The fungal conidia were one-celled and mostly ellipsoid or ovoid in shape and light gray in color and $4{\sim}20{\times}4{\sim}13\;{\mu}m$ in size. The fungal conidiophores were $14{\sim}28\;{\mu}m$ in width. The Pathogen formed sclerotia abundantly on PDA. The optimum temperature for mycelial growth and sclerotia formation was $20^{\circ}C$. Pathogenicity of the causal organism was proved according to Koch's postulates. On the basis of symptom, mycological characteristics and pathogenicity test, the fungus was identified as Botrytis cinerea. This is the first report on gray mold of Agastache rugosa caused by B. cinerea in Korea.

• The Korean Journal of Mycology
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• v.34 no.2
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• pp.122-124
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• 2006

In March of 2005, gray mold disease caused by Botrytis cinereu on Stachys sieboldii Miq. was occurred in the mud cellar storage of Gyeongsangnam-do Agricultural Research and Extension Services, Korea. The symptoms started with water-soaked and rotten in the tubers. The conidia were one celled and mostly ellipsoid or ovoid in shape and light gray in color. The conidia were $5{\sim}16{\times}4{\sim}12{\mu}m$ in size and the conidiophores were $14{\sim}30{\mu}m$ in length. The pathogen formed conidia and sclerotia abundantly on PDA. The optimal temperature for mycelial growth and sclelotia formation was $20^{\circ}C$. On the basis of symptom, mycological characteristics and pathogenicity test on host plants, the fungus was identified as Botrytis cinerea Persoon: Fries. This is the first report on gray mold of S. sieboldii caused by B. cinerea in Korea.

• The Plant Pathology Journal
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• v.36 no.6
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• pp.579-590
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• 2020

Botrytis cinerea, which causes gray mold disease in more than 200 plant species, is an economically important pathogen that is mainly controlled by synthetic fungicides. Synergistic fungicide mixtures can help reduce fungicide residues in the environment and mitigate the development of fungicide-resistant strains. In this study, we screened microbial culture extracts on Botrytis cinerea to identify an antifungal synergist for tebuconazole. Among the 4,006 microbial extracts screened in this study, the culture extract from Schizophyllum commune displayed the most enhanced activity with a sub-lethal dosage of tebuconazole, and the active ingredient was identified as schizostatin. In combination with 5 ㎍/ml tebuconazole, schizostatin (1 ㎍/ml) showed disease control efficacy against gray mold on tomato leaf similar to that achieved with 20 ㎍/ml tebuconazole treatment alone. Interestingly, schizostatin showed demethylation inhibitor (DMI)-specific synergistic interactions in the crossed-paper strip assay using commercial fungicides. In a checkerboard assay with schizostatin and DMIs, the fractional inhibitory concentration values were 0.0938-0.375. To assess the molecular mechanisms underlying this synergism, the transcription levels of the ergosterol biosynthetic genes were observed in response to DMIs, schizostatin, and their mixtures. Treatment with DMIs increased the erg11 (the target gene of DMI fungicides) expression level 15.4-56.6-fold. However, treatment with a mixture of schizostatin and DMIs evidently reverted erg11 transcription levels to the pre-DMI treatment levels. These results show the potential of schizostatin as a natural antifungal synergist that can reduce the dose of DMIs applied in the field without compromising the disease control efficacy of the fungicides.