• 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.

• Microbiology and Biotechnology Letters
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• v.30 no.4
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• pp.339-345
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• 2002

Antifungal substances were isolated from solid cultures of Fusarium equiseti FO-68 obtained from arrowhead and Fusarium sp. FO-510 obtained from egg plant, and then their antifungal activities were investigated against plant pathogenic fungi in vitro and in vivo. An antifungal substance was purifed from rice solid cultures of F. equiseti FO-68 and identified as equisetin. In addition, two antibiotic substances were isolated from solid cultures of Fusarium sp. FO-510 and their chemical structures were determined to be zearalenone and 8'-hydroxyzearalenone. in vitro, equisetin and zearalenone inhibited mycelial growth of most of the plant pathogenic fungi tested, whereas 8'-hydroxyzearalenone hardly inhibited fungal growth. In vitro, equisetin effectively controlled the development of tomato gray mold and tomato late blight. Zearalenone exhibited in vivo antifungal activity against rice blast, rice sheath blight, tomato gray mold, and tomato late blight. However, 8'-hydroxyzearale-none did not control the development of plant diseases except tomato gray mold. This is the first report on the antifungal activities of equisetin, zearalenone, and 8'-hydroxyzearalenone.

• 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.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.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.165-171
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• 2009

Biological control activity of Acremonium strictum BCP, a mycoparasite on Botrytis cinerea, was examined against six plant diseases such as rice blast, rice sheath blight, cucumber gray mold, tomato late blight, wheat leaf rust, and barley powdery mildew in growth chambers. The spore suspension of strain BCP showed strong control activities against five plant diseases except against wheat leaf rust. On the other hand, the culture filtrate of A. strictum BCP was effective in controlling only cucumber gray mold and barley powdery mildew. Further in vivo biocontrol activities of A. strictum BCP against tomato gray mold were investigated under greenhouse conditions. Control efficacy of the fungus on tomato gray mold increased in a concentration-dependent manner. Treatment of more than $1{\times}10^6$ spores/ml significantly controlled the disease both in tomato seedlings and in adult plants. The high disease control activity was obtained from protective application of the strain BCP, whereas the curative application did not control the disease. Foliar infections of B. cinerea were controlled with $1{\times}10^8$ spores/ml of A. strictum BCP applied up to 7 days before inoculation. In a commercial greenhouse, application of A. strictum BCP exhibited the similar control efficacy with fungicide procymidone (recommended rate, $500{\mu}g/ml$) against strawberry gray mold. These results indicate that A. strictum BCP could be developed as a biofungicide for Botrytis diseases under greenhouse conditions.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.207-213
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• 2005

Cultural, morphological and pathogenic variation in Indian isolates of Ascochyta rabiei, the causal agent of blight of chickpea, was investigated. Fungal isolates representative of seven agroclimatic regions in north western plain zones (NWPZ) of India showed variation in colony colour as mouse gray with green hue, light mouse gray with slate gray centre and gray with dark brown centre, when grown on chickpea dextrose agar (CDA). Conidiomatal color of the isolates varied from brown to slate gray and black. The number of conidiomata and conidia formed on CDA ranged from 49.7 to 90.7 and $5.5\times10^4\;to\;3\times10^5cm^{-2}$, respectively. The size of conidiomata and conidia of A. rabiei isolates varied from $274\times232{\mu}m\;to\;156\times116{\mu}m$, and from $14.0\times6.2{\mu}m\;to\;10.7\times4.6{\mu}m$, respectively. Fourteen A. rabiei isolates from the seven agroclimatic regions of NWPZ were evaluated for their virulence on 180 chickpea genotypes in controlled environment. Cluster analysis based on the disease rating on a 1-9 scale indicated higher similarity coefficient (> 0.65) between isolates from different agroecological regions, while few isolates from the same region had less similarity. The 14 isolates were grouped into eight pathotypes at > 0.5 similarity coefficient. Sixteen genotypes were identified as probable differentials to distinguish A. rabiei isolates.

• Research in Plant Disease
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• v.12 no.2
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• pp.85-90
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• 2006

Bacillus subtilis BD0310 isolated from tea leaves was used for the development of a biofungicide against Pestalotiopsis longiseta causing gray blight of tea plants. The optimum growth conditions were investigated for the mass cultivation of the microbial agent. The optimum temperature and cultivation time were determined as $12{\sim}24$ hours at $30^{\circ}C$ and the optimum initial pH was pH 7.0 in nutrient broth. Among the tested carbon sources of fructose, galactose, glucose, glycerol, inositol, lactose, maltose, sorbitol and starch, maltose and inositol were found to highly increase antifungal activity of the microbial agent against P. longiseta. Yeast extract and tryptone apparently increased antifungal activity of the microbial agent among the tested nitrogen sources of casein, tryptone, malt extract, yeast extract and $(NH_4)_2SO_4$. The results will make a contribution to mass production of the antagonistic bacterium Bacillus subtilis BD0310 for development of a microbial agent controlling gray blight of tea plants.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.305-307
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• 2001

In March 2000, gray mold was found on day lily (Hemerocallis fulva L.) in Korea. Among the symptoms observed was blight or early rot with chlorotic halo of the leaves. All the isolates obtained from the lesions of the diseased plant parts were identified as Botrytis elliptica, based on the morphological characteristics of conidia. Conidia that formed on conidiogenous cells were not in chains, hyaline to pale brown, unicellular, ellipsoidal to obovate with a single hilum at the base, entirely verruculose, and 21-31 x 12-$23\mu\textrm{m}$ in size. Pathogenicity of the fungus was established by artificial inoculation on day lily plants. This is the first record of gray mold on day lily caused by B. elliptica in Korea.

• The Plant Pathology Journal
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• v.26 no.2
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• pp.170-177
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• 2010

Bacillus licheniformis N1, previously developed as a biofungicide formulation N1E to control gray mold disease of plants, was investigated to study the bacterial traits that may be involved in its biological control activity. Two N1E based formulations, bacterial cell based formulation PN1E and culture supernatant based formulation SN1E, were evaluated for disease control activity against gray mold disease of tomato and strawberry plants. Neither PN1E nor SN1E was as effective as the original formulation N1E. Fractionation of antifungal compounds from the bacterial culture supernatant of B. licheniformis N1 indicated that two different cyclic lipopeptides were responsible for the antimicrobial activity of the N1 strain. These two purified compounds were identified as iturin A and surfactin by HPLC and LCMS. The purified lipopeptides were evaluated for plant disease control activity against seven plant diseases. Crude extracts and purified compounds applied at 500 ${\mu}g/ml$ concentration controlled tomato gray mold, tomato late blight and pepper anthracnose effectively with over 70% disease control value. While iturin showed broad spectrum activity against all tested plant diseases, the control activity by surfactin was limited to tomato gray mold, tomato late blight, and pepper anthracnose. Although antifungal compounds from B. licheniformis N1 exhibited disease control activity, our results suggested that bacterial cells present in the N1E formulation also contribute to the disease control activity together with the antifungal compounds.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1999.04a
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• pp.26.3-27
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• 1999