• Research in Plant Disease
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• v.18 no.3
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• pp.217-224
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• 2012

Post-harvest rot of grape causes a severe economic loss and lower of the grape quality. It is also one of the important limiting factors for grape export. Grape rots and their casual agents on 'Red Globe' variety imported from Chile were identified. Grapes shown rotting symptom were collected from the storages near the import harbor. The 3 different rots were identified on the imported 'Red Globe'; melting decay, gray mold, and blue mold. A bacterium that isolated from a typical melting decay symptom was identified as Gluconobacter cerinus on basis of its nucleotide sequence of 16S rDNA and fatty acid profile. By inoculation on grape, it caused cracking and dissolution of epidermis of grape which were the characteristics of melting decay. Botrytis cinerea and Penicillium expansum were isolated from grapes showing gray mold and blue mold. The 2 fungal isolates were identified on basis of their morphological characteristics and nucleotide sequence of their beta-tubulin genes. They showed strong pathogenicity on 'Campbell Early' variety that is a major table grape in Korea.

• Research in Plant Disease
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• v.9 no.3
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• pp.170-173
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• 2003

For the effective chemical control to minimize infection of storage pathogens on kiwifruit in the field, this study was conducted to screen alternative fungicides which could be substituted for the fungicides Benomyl WP and Thiophanate-methyl 제 registered for the control of postharvest fruit rats of kiwifruit in Korea. Among the 8 fungicides tested, Tebuconazole WP, Iprodione WP and Flusilazole WP showed higher inhibitory effects on themycelial growths of 3 major pathogens of postharvest fruit rots, Botryosphaeria dothidea, Diaporthe actinidiae and Botrytis cinerea on potato dextrose agar. They also showed control efficiencies as high as those of Benomyl WP and Thiophanate-methyl WP on postharvest fruit rots in the field. They might be good candidates for fungicieds for the control of postharvest fruit rots of kiwifruit.

• Korean Journal Plant Pathology
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• v.13 no.4
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• pp.225-231
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• 1997

Activities of polygalacturonase, laccase, and intra- and extra-cellular $\beta$-glucosidase produced by 20 Botrytis cinerea isolates in liquid culture media containing cucumber cell was as a carbon source were measured and their relationships to the pathogenicity were analyzed. No significant correlations between these enzyme activities and the pathogenicity of B. cinerea were found. Mycelial growth rate on Bayendamm media, however, was higthly correlated with the pathogenicity (r=0.522) anong these isolates. Immuno-blot analysis of the culture filtrate using antibody against against exo-polygalacturonase revealed that only one band with molecular weight of 66 kDa was detected amone 34 tested isolates. It appears that these enzymes may not be primary factors in dermining the pathogenicity of B. cinerea.

• The Korean Journal of Mycology
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• v.41 no.1
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• pp.38-41
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• 2013

In 2010 and 2011, gray mold was found on common fig (Ficus carica) fruit grown at the research field of Jeollabuk-do Agricultural Research and Extension Services, Korea. Gray mold symptoms on common fig fruit mainly occurred after harvest season until December. The typical symptom included brown water-soaked rot and fruit decay. The diseased fruit was covered by gray to brown colored conidiophore and conidia. The conidiophores were tree shape and measured $15-33{\times}2{\mu}m$. Conidia on conidiophore were ellipsoidal or lemon shape, colorless, single cell, and measured $7.3-14.6{\times}6.8-11.1{\mu}m$. The nucleotide sequences of the rDNA ITS region obtained from the pure culture of the gray mold on common fig were 100% similar to the sequences of the GenBank accession number HQ171052, EU519210, HQ171053, FN812726, HM849615, and EU563120 of B. cinerea isolates. In phylogenetic tree, the representative isolate was placed within same clade of B. cinerea. Based on the morphological characteristics and analysis of rDNA ITS sequence data, the fungus was identified as B. cinerea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.90.2-91
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• 2003

In commercial greenhouses, senescent flower petals or flowers of vegetables such as tomato, strawberry, hot pepper and zucchini squash were blighted to be removed from fruits within five days after spraying of Trichoderma harzianum YC459 (TORY), a biocontrol agent for the gray mold rot of vegetables caused by B. cinerea The mechanism for selective colonization of senescent floral tissues by T. harzianum YC459 was elucidated using fresh and senescent (Hays and 14days after flowering, respectively) floral tissues of zucchini squash (Cucurbita moschata Duchesne). The spores of T. hrzianum YC459 were produced more on agar and liquid culture media supplemented with 5％ dry powder of senescent floral tissues than fresh tissues during 15days. Mycelial growth was also much better in the media with senescent tissues than with fresh tissues. Enzyme activities of amylase, polygalacturonase and cellulase in the liquid media which might be involved in the colonization of tissues by T. harzianum YC459 were compared. The activities of three enzymes were much higher in the media with senescent floral tissues than with fresh floral tissues reaching to the maximum during 9 to 12days of incubation. Based on the results, the removal of senescent floral tissues, a possible inoculum source of the pathogen, may be another mechanism for biocontrol of gray mold rot of vegetables by T. harzianum YC459.

• The Plant Pathology Journal
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• v.16 no.5
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• pp.286-289
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• 2000

Mechanol extracts of three cold-tolerant eucalyptus trees-Eucalyptus darlympleana, E. gunnii and E. unigera were screened for antimicrobial activity against twenty two phyto-pathogenic fungi and six food-borne bacterial pathogens. E. unigera showed the antagonistic activity against all the tested pathogens. Among the tested fungal pathogens, Pythium species were highly sensitive to the leaf extracts. Especially, P. vanterpoolii, a causal agent of leaf blight in creeping bentgrass (Agrostis palustris), was completely inhibited by the extracts. The eucalyptus extracts were also effective in inhibiting the fungal growth of Botrytis cinerea and Phomopsis sp. isolated from the lesions of kiwifruit soft rot during post-harvest storage. Escherichia coli O-157 was less sensitive to the inhibition than the other bacterial pathogens tested. It was likely that Gram positive bacteria-Bacillus subtilis and Streptococcus mutans were more sensitive to the eucalyptus extracts than Gram negative bacteria-Escherichia coli, Salmonella enteritidis and Pseudomonas aeruginosa. Our findings suggest that the cold-tolerant eucalyptus species have antimicrobial properties that can serve the development of novel fungitoxic agents or food preservatives.

• Korean Journal of Organic Agriculture
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• v.17 no.2
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• pp.253-264
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• 2009

This study was conducted to establish agricultural practices to control diseases and insects for chemical pesticide-free cultivation of leafy vegetables. Two diseases, gray mold(Botrytis cinerea) and soft rot(Erwinia carotovora), on lettuce were reduced by controlling temperature and humidity using air-circulation fan. The aphidophagous lady beetle(Harmonia axyridis) and primary parasitoids(Aphidius colemani) showed activity to control aphids density on Chinese cabbage. Co-application of cooking oil and yolk mixture (COY) and BT(Bacillus thuringiensis) decreased diseases including soft rot(Erwinia carotovora), downy mildew(Peronospora brassicae Gaumann), and powdery mildew(Eryslphe polygoni), and insects such as diamondback moth(Plutella xylostella) and beet armyworm(Spodoptera exigua Hubner). Neem extract treatment reduced downy mildew(Peronospora destructor) on Welsh onion.

• The Plant Pathology Journal
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• v.17 no.3
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• pp.141-148
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• 2001

Postharvest decay of onion bulbs was examined by inspecting the commercial packages in the market or in storage. Bulb rot incidence was unexpectedly high, and onion bulbs with 1st quality grade were rotten most severely by 51%, followed by 32% for 2nd and 21% for 3rd grades. This indicates that larger bulbs had higher incidences of bulb rots. Major pathogens associated with basal and neck rots were Fusarium oxysporum and Aspergillus sp. or Botrytis allii, respectively, of which basal rot was most prevalent and damaging during storage. Among the epiphytic microorgani는 from onion plants, several Bacillus and Paenibacillus spp. and previously selected Pseudomonas putida and Trichoderma harzianum had inhibitory efficacy against bulb rot pathogens. Among these B. amyloliquefaciens BL-3, Paenibacillus polymyxa BL-4, and P. putida Cha 94 were highly inhibitory to conidial germination of F. oxysporum and B. allii. P. putida Cha 94, B. amyloliquefaciens BL-3, P. polymyxa BL-4, and T. harzianum TM were applied in the rhizoplane of onion at transplanting. Initially antagonist populations decreased rapidly during the first one month. However, among these antagonists, rhizoplane population densities of BL-3, Cha 94, and TM were consistently high thereafter, maintaining about 10$^4$-10$^{5}$ cells or spores per gram of onion root up to harvest time. The other bacterial antagonist BL-4 survived only for two months. TM was the most effective biocontrol agent against basal rot, with the number of rotten bulbs recorded at 4%, while that of the control was 16%. Cha 94 was effective for the first 20 days, but basal rot increased thereafter and had about the same control efficacy as that of BL-3 and BL-4. When the antagonists were applied to the topping areas of onion bulbs at harvest, TM was the most effective in protecting the stored onion bulbs from neck rotting. The second effective antagonist was BL-3. TM and BL-3 completely suppressed the neck rot in another test, suggesting that biocontrol of postharvest decay of onion using these microorganisms either at the time of transplanting or at harvesting may be promising.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1018-1026
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• 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.

• The Korean Journal of Mycology
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• v.40 no.1
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• pp.44-48
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• 2012

Ginseng (Panax ginseng) is one of the most widely cultivated medicinal herb in Korea. However, yield losses reached up to 30~60 % due to various diseases during 3 or 5 years of ginseng cultivation. Therefore, successful production of ginseng roots depends primarily on the control of diseases. The objective of this study is to select potential multifunctional biocontrol agents from actinomycetes for the control of multiple ginseng diseases as an alternative to fungicides. Ninety three Streptomyces strains were selected and their ability to produce antibiotics, siderophore and lytic enzymes such as protease and cellulose were investigated. Eight of the isolates, strains A75, A501, 515, 523, A704, A1444, A3265 and A3283 produced cellulase and protease. These strains also produced siderophore and showed potent antifungal activity against Botrytis cinerea, Cylindrocarpon destructans, Collectotricum gloeosporioides, Phytophthora capsici and Rhizoctonia solani causing ginseng root rot.