• Mycobiology
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• v.39 no.4
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• pp.313-316
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• 2011

The ambrosia beetle, Platypus koryoensis, is a serious pest of oak trees in Korea. In this study we investigated filamentous fungi present in the body of the beetle. Fourteen genera of filamentous fungi belonging to Ascomycota and Basidiomycota were isolated. Among the isolated fungi, some were able to produce wood degrading enzymes. This is first report of fungi associated with P. koryoensis.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.45-56
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• 2009

Current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the organic or non-chemical pest control orchards from 2005 to 2009. Numbers of certified organic or non-chemical apple orchards were increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits occurred by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective to control under the adequate conditions. At present, it is extremely difficult to produce organic apples in Korea. Growers must consider about and solve so many conditions on the cultivar, weather, local site, marketing and so on, before when they decide to change from conventional or IPM(Integrated Pest Management) to organic or non-chemical pest control orchards.

• Korean Journal of Organic Agriculture
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• v.18 no.2
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• pp.221-232
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• 2010

During 2005~2009, current status on the occurrence and the management of the major disease, insect and mite pests were investigated in the non-chemical or organic cultured apple orchards in Korea. Numbers of certified organic or non-chemical apple orchards increased from 14 in 2005 to 78 in 2008. Severe damages on leaves and fruits were caused by the several diseases such as marssonina blotch, bitter rot, white rot, sooty blotch and flyspeck, and the several insect pests such as apple leaf-curling aphid, woolly apple aphid, oriental fruit moth and peach fruit moth on the almost certified organic or non-chemical pest control orchards. About 10 and 18 environmental-friendly materials were used to control diseases and insect or mite pests, respectively. But, lime sulfur and bordeaux mixture to diseases and machine oil, plant oil mixed with egg yolk, and pheromone mating disruptions to insect pests were effective under the adequate conditions.

• Korean Journal of Organic Agriculture
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• v.25 no.2
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• pp.419-429
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• 2017

We investigated the occurrence pattern of diseases and insect pests and disease control efficacy of organic materials against watermelon powdery mildew in small type watermelon in Eumseong, Chungcheongbuk-do, 2015. The result of this study, the small type watermelon was damaged by diseases and pests such as Didymella bryoniae, Podosphaera xanthii, Aphis gossypii, Tetranychus urticae, thrips, Spodoptera exigua and Spodoptera litura. Among them, the occurrence of P. xanthii, T. urticae and thrips was high. Diseased leaf rate by P. xanthii, a casual agent of powdery mildew, was 27~99.3% in three small type watermelon cultivars in the middle of June. The number of T. urticae per leaf was high from 79.9 to 111 in three small type watermelon cultivars in the middle of June. It showed high number of thrips captured by yellow and blue sticky trap. Highest numbers of yellow sticky trap (407) and of blue sticky trap (774) were detected in the middle and first of June, respectively. The disease control efficacy of mayonnaise, oleic acid and three organic materials against powdery mildew of small type watermelon in fields was evaluated. As thre results, the symptoms of plant disease were effectively reduced by over 60% in the treatments of materials such as sodium bicarbonate 80%, mayonnaise and the extract of Rheum palmatum 1%. The highest control efficacy was 83% in the treatment of sodium bicarbonate 80%. From this study, we had a information of the occurrence pattern of diseases and insect pests in small type watermelon and the treatment of material containing sodium bicarbonate 80% was very effective for controlling against powdery mildew.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.77-80
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• 2004

For the development of the alternative control system against the major forest pests, Beauveria spp. F-101, isolated from a dead larva of Thecodiplosis japonensis, was selected because this isolate showed high pathogenicities against T. japonensis and Acantholyda parki. Beauveria spp. F-101 had irregular clustered conidio-phores and conidia borne on a distinctive apical zigzag extension, and it showed typical characteristic of the genus, Beauveria in morphology. For molecular based-identification, the ribosomal ITS region of Beauveria spp. F-101 was amplified with ITS1 and ITS4 primers, and cloned into pGEM- T Easy vector. The amplified PCR product was 569 bp in size and completely sequenced. The similarities of the cloned ITS sequence were 99 ％ and 97％ to those of B. bassiana and B. brongniartii, respectively. In comparison to other species among the genus Beauveria, the ITS region of Beauveria spp. F-101 showed a similarity of 95％ to B. amorpha, 95％ to B. tenella, 89％ to B. vermiconia and 69％ to B. alba, respectively. In addition, in comparison to different genus, it had 95％ similarities to Cordyceps militaris and 91％ to Paecilomyces tenuipes. Accordingly, the current result suggests that Beauveria spp. F-101 was a variant of B. bassiana and it seems to be a new isolate considering sequence variation in ITS region.

• International Journal of Industrial Entomology and Biomaterials
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• v.10 no.2
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• pp.131-136
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• 2005

Beauveria bassiana F-101, which has high toxicity toward Acantholyda parki as well as Thecodiplosis japonensis, was an isolate to develop an alternative control system against the major forest pests. Up to now, in B. bassiana, only one pr1 gene has been isolated and characterized. Therefore, we here reported the identification of a pr1-like gene, which would be a factor of toxicity from B. bassiana F-101. The oligonucleotides for the amplification of the pr1-like gene, were chosen based on the conserved regions of the subtilisin family enzymes, pr1 genes of B. bassiana and Metarhizium anisopliae, and proteinase K of Tritirachium album. The cloned PCR fragment had 1111 bp including 52 bp intron. The deduced Pr1-like peptide showed a low identity with Pr1s of entomopathogenic fungi such as B. bassiana Pr1 (BbPr1) and M. anisopliae Pr1 (MaPr1) as well as the proteinase K of T. album (TaPrK). Instead, the deduced peptide had a substantially high amino acid sequence identity $(>65\%)$ with the serine proteases of Magnaporthe grisea (MgSPM1) and Podospora anserina (PaPspA). These results, therefore, appear to suggest that the putative Pr1-like peptide of B. bassiana F-101 belongs to the subtilisin-like serine protease family and may be a novel gene.

• International Journal of Industrial Entomology and Biomaterials
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• v.14 no.1
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• pp.33-36
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• 2007

To improve insecticidal activity of B. thuringiensis 2385-1 (Bt 2385-1), a recombinant plasmid, pHT1K-1Ac, was introduced into lepidopteran toxic Bt 2385-1 by electroporation. The presence of the recombinant plasmid in Bt 2385-1 after electroporation was confirmed by PCR. Bt 2385-1 transformant was named as Bt pHT1K-1Ac/2385-1 (1K-1Ac/2385-1). The 1K-1Ac/2385-1 transformant produced bipyramidal-shaped parasporal inclusion as like the wild-type strain, Bt 2385-1, and showed an 130 kDa band of Cry1Ac protein. The insecticidal activity of 1K-lAc/2385-1 against S. exigua was similar to that of Bt 2385-1 but the $LC_{50}$ value of transformant against P. xylostella was 1.8 times lower. Through these bioassay results, it was confirmed that toxicity of Bt 2385-1 transformant showed synergistic effect by introducing Cry1Ac. These results suggested that the multiple expressions of Cry proteins in a promising Bt strain may interact synergistically in insect midgut, resulting in increase of toxicity and expansion of host spectrum.

• The Korean Journal of Pesticide Science
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• v.7 no.2
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• pp.83-91
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• 2003

Methanol extracts from 207 samples of 118 plant species in 44 families were tested for their fungicidal activities against six phytopathogenic fungi. Extracts of Thuja orientalis leaf, Cinnamomum loureirii leaf, Lindera erythrocarpa barks and leaf, Pinus koraiensis wood, Hovenia dulcis wood, Koelreuteria paniculata barks, Styrax japonica wood, Camelia japonica leaf and Cleyera japonica leaf showed very strong fungicidal activity against more than two phytopathogenic fungi at a concentration of 2000 ppm. As a naturally occurring fungicide, these plants could be useful as new fungicidal products against various plant diseases induced by plant pathogens.

• The Plant Pathology Journal
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• v.29 no.1
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• pp.116-122
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• 2013

To evaluate the mechanisms of pathogenicity and nonpathogenicity of Bursaphelenchus xylophilus and B. mucronatus isolated in South Korea, we used 4-year-old P. thunbergii seedlings and 20-cm long one-year-old stem cuttings of 5-year-old Pinus thunbergii, and studied distributions and multiplications of pine wood nematodes after inoculation. The distributions of B. xylophilus in the 20-cm pine stem cuttings were not significantly different from that of B. mucronatus. Conversely, the proliferation rate of B. xylophilus on mycelial mats of Botrytis cinerea was significantly different from that of B. mucronatus. The study using 4-year-old P. thunbergii seedlings also showed that B. mucronatus can migrate to distal portions of the pine seedlings the same as B. xylophilus, but the populations of B. xylophilus remaining in the pine seedlings were relatively larger than those of B. mucronatus. Therefore, we concluded that the pathogenicity of B. xylophilus could be strongly influenced by its ability to multiply.

• Mycobiology
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• v.49 no.3
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• pp.275-279
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• 2021

A fungus of the genus Kordyana, found on leaves of Commelina communis and C. minor exhibiting white smut-like symptoms, was identified as Kordyana commelinae based on morphological characteristics and two rDNA sequence analyses. We report the novel occurrence of the genus Kordyana in Korea and the association of K. commelinae with the host plant species. As well, we provide the necessary mycological information to resolve species delimitation and taxonomic problems of Kordyana.