• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.376-383
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• 2022

The current study, which consisted of two independent studies (laboratory and greenhouse), was carried out to project the hypothesis fungi-spray scheduling for leaf mold and gray leaf spot in tomato, as well as to evaluate the effect of temperature and leaf wet duration on the effectiveness of different fungicides against these diseases. In the first experiment, tomato leaves were infected with 1 × 10⁴ conidia·mL^-1 and put in a dew chamber for 0 to 18 hours at 10 to 25℃ (Fulvia fulva) and 10 to 30℃ (Stemphylium lycopersici). In farm study, tomato plants were treated for 240 hours with diluted (1,000 times) 30% trimidazole, 50% polyoxin B, and 40% iminoctadine tris (Belkut) for protection of leaf mold, and 10% etridiazole + 55% thiophanate-methyl (Gajiran), and 15% tribasic copper sulfate (Sebinna) for protection of gray leaf spot. In laboratory test, leaf condensation on the leaves of tomato plants were emerged after 9 hrs. of incubation. In conclusion, the incidence degree of leaf mold and gray leaf spot disease on tomato plants shows that it is very closely related to formation of leaf condensation, therefore the incidence of leaf mold was greater at 20 and 15℃, while 25 and 20℃ enhanced the incidence of gray leaf spot. The incidence of leaf mold and gray leaf spot developed 20 days after inoculation, and the latency period was estimated to be 14-15 days. Trihumin fungicide had the maximum effectiveness up to 168 hours of fungicides at 12 hours of wet duration in leaf mold, whereas Gajiran fungicide had the highest control (93%) against gray leaf spot up to 144 hours. All the chemicals showed an around 30-50% decrease in effectiveness after 240 hours of treatment. The model predictions in present study could be help in timely, effective and ecofriendly management of leaf mold disease in tomato.

• Korean Journal of Environmental Agriculture
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• v.28 no.4
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• pp.435-441
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• 2009

In the present study, we analyzed the defensin protein deduced from Korean radish (Raphanus sativus L.) seeds.To express the genes in E. coli, we constructed a recombinant expression vector with a defensin gene, named rKRs-AFP gene isolated from Korean radish seeds. Over expressed rKRs-AFP proteins was separated by SDS-PAGE to determine the purity, and protein concentration was determined by the Bradford method. Antifungal activity was assessed by disk assay method against the tested fungi. As a result, when 500 mL of cell culture were disrupted by sonicator, 32.5 mg total proteins were obtained. The purified protein showed a single band on SDS-PAGE with estimated molecular weight about 6 KDa, consistent with the molecular mass calculated from the deduced amino acid sequence. The purified rKRs-AFP protein showed remarkable antifungal activities against several fungi including Aspergillus niger, Botrytis cinerea causing the gray mold disease, and Candida albicans. In field tests using the purified rKRs-AFP protein, the protein showed the reducing activity of disease spot and the mitigating effect of spreading of disease like agrichemicals. The immuno-assay of rKRs-AFP protein showed that the purified protein entirely accumulated at B. cinerea cytoplasm through the hyphal septa shown by fluorescence imaging. There was no fluorescence inside the cell, when the hypha was incubated without the protein. These all results indicate that the recombinant rKRs-AFP proteins can be utilized as a potential antifungal drug to control harmful plant fungal pathogens.

• Mycobiology
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• v.42 no.3
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• pp.262-268
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• 2014

Several postharvest diseases of table grapes (Vitis vinifera) occur during storage, and gray mold rot is a particularly severe disease because the causal agent, Botrytis cinerea, grows at temperatures as low as $0^{\circ}C$. Other postharvest diseases, such as those caused by Penicillium spp. and Aspergillus spp., also often lead to deterioration in the quality of table grapes after harvest. The use of plant essential oils such as thymol and linalool, to reduce postharvest diseases in several kinds of fruits, including table grapes and oranges, has received much attention in European countries. However, to the best of our knowledge there has been no report of the use of thymol fumigation to control gray mold in table grapes in Korea. Thymol ($30{\mu}g/mL$) and linalool ($120{\mu}g/mL$) significantly inhibited mycelial growth and conidia germination of B. cinerea. The occurrence rate of gray mold rot of B. cinerea and other unknown fungi was significantly reduced by fumigation with $30{\mu}g/mL$ thymol in several table grape cultivars, such as Campbell early, Muscat Bailey A, Sheridan, and Geobong. In this study, fumigation with $30{\mu}g/mL$ thymol, had no influence on the sugar content and hardness of grapes, but reduced fungal infection significantly. This suggests that $30{\mu}g/mL$ thymol could be utilized to reduce deterioration of grapes due to gray mold and other fungal infections during long-term storage.

• Research in Plant Disease
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• v.13 no.3
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• pp.216-219
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• 2007

Gray mold caused by Botrytis cinerea occurred on Prunus mume Sieb. & Zucc. in an experimetal orchard of Gyeongsangnam-do Agricultural Research and Extension Services in Korea from 2005 to 2007. The symptoms usually started with water-soaking lesions and hollow depression on the fruit surface. The conidia of the pathogen appeared on the surface fruits. The conidia were one celled and mostly ellipsoid or ovoid in shape and were colorless or pale brown in color. The conidia were $6{\sim}17{\times}4{\sim}10{\mu}m$ in size and conidiophores were $15{\sim}30{\mu}m$ in length. The sclerotial formed abundantly on potato-dextrose agar, They were flat or irregular in shape and black in color The optimum temperature for sclerotial formation was $20^{\circ}C$. On the basis of 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 P. mume caused by B. cinerea by in Korea.

• Mycobiology
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• v.47 no.1
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• pp.87-96
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• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.

• Research in Plant Disease
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• v.17 no.3
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• pp.364-368
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• 2011

Gray mold caused by Botrytis cinerea was found on a carrot seedling in a greenhouse and a field at Daegwallryeong, Gangwon Province in 2007-2009. Symptoms included irregular, brown, blight, or chlorotic halo on leaves and petioles of the carrots. Fungal conidia were globose to subglobose or ellipsoid, hyaline or pale brown, nonseptate, one celled, $7.2-18.2{\times}4.5-11\;{\mu}m$ ($12.1{\times}8.3\;{\mu}m$) in size, and were formed on botryose heads. B. cinerea colonies were hyaline on PDA, and then turned gray and later changed dark gray or brown when spores appeared. The fungal growth stopped at $35^{\circ}C$, temperature range for proper growth was $15-25^{\circ}C$ on MEA and PDA. Carrots inoculated with $1{\times}10^5$ ml conidial suspension were incubated in a moist chamber at $25{\pm}1^{\circ}C$ for pathogenicity testing. Symptoms included irregular, brown, water-soaked rot on carrot roots and irregular, pale brown or dark brown, water-soaked rot on leaves. Symptoms were similar to the original symptoms under natural conditions. The pathogen was reisolated from diseased leaves, sliced roots, and whole roots after inoculation. As a result, this is the first report of carrot gray mold caused by B. cinerea in Korea.

• Research in Plant Disease
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• v.25 no.1
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• pp.16-21
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• 2019

Botrytis cinerea is the pathogen for a gray mold generating problems during the cultivation and transportation of roses. But there is little information about the difference of the symptom severity caused by gray mold on rose varieties and pathogen strains. 16 strains were collected from the rose cultivation area to confirm the degree of disease occurrence against strains and each variety. Collected 16 strains were identified based on the sequences analysis of ITS region of ribosomal DNA by using specific primers. The sequence analysis was performed by comparing the sequences to find a difference. To confirm the difference in disease occurrence for each strains, the difference was classified from 0 to 5 stages using charmant variety as a control. The data was confirmed through Kruskal-Wallis ANOVA. The result showed the significant difference in the pathogenicity caused by strains. WNG6_5 showed the lowest pathogenicity with 0.24 and WNG6_3 showed the highest with 3.20. The difference between two strains were almost 3.0. In addition, nine varieties of roses were more investigated with three strains such as the strains of WNG6_5, Hwa_1, and WNG6_3. The result showed that the Love Letter variety showed resistance and the Ice Bear variety was sensitive to three strains. Taken together, this study showed the significant difference by the interactions of rose varieties and gray mold strains.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.184-191
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• 2004

Methanol extracts of fresh materials of 57 plants were screened for in vivo antifungal activity against Magna-porthe grisea, Corticium sasaki, Botrytis cinerea, Phyto-phthora infestans, Puccinia recondita, and Blumeria graminis f. sp. hordei. Among them, seven plant extracts showed disease-control efficacy of more than 90％ against at least one of six plant diseases. None of the plant extracts was highly active against tomato gray mold. The methanol extracts of Chloranthus japonicus (roots) (CjR) and Paulownia coreana (stems) (PcS) displayed the highest antifungal activity; the CjR extract controlled the development of rice blast, rice sheath blight, and wheat leaf rust more than 90％, and tomato gray mold and tomato late blight more than 80％. The PcS extract displayed control values of more than 90 ％ against rice blast, wheat leaf rust, and barley powdery mildew and more than 80％ against tomato gray mold. The extract of PcS also had a curative activity against rice sheath blight and that of CjR had a little curative activity against rice blast. On the other hand, the extract of Rumex acetocella roots reduced specifically the development of barley powdery mildew. Further studies on the characterization of antifungal substances in antifungal plant extracts are underway and their disease-control efficacy should be examined under greenhouse and field conditions.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.483-488
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• 2014

Lime-bordeaux mixture (LBM) has been used instead of pesticides in ginseng field and orchard since the 1960's in Korea. In this experiment, LBM was made with different concentrations and sprayed in the field of ginseng for eco-friendly cultivation. Growth characteristics and disease such as alternaria blight, anthracnose, and gray mold were investigated in 4-5 year old ginseng after spraying LBM. LBM caused a little damage on leaf when it was sprayed at the time of leafing stage, late April and early May. Root weights of five-year-old ginseng were 43.1~51.5 g and 41.2~46.6 g in the plot of mid-April and mid-May treatments, respectively. These growth levels were further reduced as compared with that of the chemicals treatment plot. The rate of diseases in the plot of 6-6 and 8-8 ratio were 0.0~4.8% and 0.0~4.4%, respectively, which was similar with that in the plot of chemical control for alternaria blight and anthracnose. However, LBM had little effect on controling gray mold. It showed lower control effect in the plot of 4-4 ratio than that of chemical control. This result will be expected to be a useful guide that can be used in the field to the farmers of the ginseng.

• Research in Plant Disease
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• v.12 no.2
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• pp.115-118
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• 2006

In February of 2000-2001, the gray mold disease occurred on nephrolepis (Nephrolepis sp.) grown in a flower nursery farm in Suwen, Korea. Typical symptoms were water-soaked brown or blackish lesions on terminal leaf blades. Severely infected leaves were entirely blighted with grayish fungal mycelia formed on the surface. Conidia of the fungus in mass were hyaline or gray, 1-celled, mostly ellipsoid or ovoid and $13.5{\sim}16.9{\times}6.8{\sim}9.2{\mu}m$ in size. Conidiophores were formed on PDA with $8.7{\sim}11.1{\mu}m$ in width. The sclerotia were readily formed within 2 or 3 days on PDA. In addition, the Biolog database gave the causal fungus a high similarity to Botrytis cinerea (78%) with a match probability of 100%. Pathogenicity of the causal organism was proved according to Koch's postulate. The causal organism was identified as Eotrytis cinerea based on its mycological characteristics and utilization of carbon sources with Biolog system as supporting data. This is the first report of gray mold of nephrolepis caused by Botrytis cinerea in Korea.