• Research in Plant Disease
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• v.23 no.2
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• pp.114-149
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• 2017

World-wide crop loss caused by insect pest and nematode reaches critical level. In Korea, similar crop loss has been gradually augmented in the field and greenhouse due to continuous crop rotation. The current methods on controlling herbivorous insects and plant parasitic nematodes are mostly depended on agro-chemicals that have resulted additional side-effect including occurrence of resistant insects and nematodes, environmental contamination, and accumulation in human body. To overcome the pitfalls, microbe-based control method have been introduced and applied for several decades. Here, we revised biological control using by the bacteria, fungi, and virus in order to kill insect and nematode and to attenuate its virulence mechanism. The introduced microbes mainly secreted out the hydrolysing enzymes and toxic compounds to target host membrane or cell wall directly. Indirectly, the microbe-triggered plant innate immunity against insects and nematodes was also reported. In conclusion, we provide a new frontier of microbe-based environmentally friendly procedure and effective methods to manage insects and nematodes.

• Korean journal of applied entomology
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• v.58 no.1
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• pp.9-13
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• 2019

Nematode-trapping fungi use various specialized traps to capture nematodes. A fungus that can capture nematodes in three dimensional adhesive networks was isolated from the soil around the root of Cucumis melo L. (Oriental melon) in Seongju, Korea. The conidiophores were found to be septate, hyaline, erect and $290-528(342.8){\mu}m$ high. It produces obovoid shape and 1-3 septate (commonly 2-septate) conidia with a size of $30.5{\times}20.3{\mu}m$. Molecular analysis of 5.8 S rDNA displayed 99% similarity to Arthrobotrys sinensis. On the basis of morphological, morphometric and molecular studies, the fungus was identified as A. sinensis. It is the first report in Korea which can be one of biological control resource of plant-parasitic nematode.

• Korean journal of applied entomology
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• v.52 no.1
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• pp.35-43
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• 2013

All tested Korean populations of the diamondback moth, Plutella xylostella, are known to be resistant especially against pyrethroid insecticides by mutation in its molecular target, para-sodium channel. Moreover, P. xylostella is able to develop resistance against most commercial insecticides. This study was performed to develop an efficient control technique against P. xylostella by a combined treatment of an endoparasitoid wasp, Cotesia plutellae, and a microbial insecticide, Bacillus thuringiensis. To investigate any parasitism preference of C. plutellae against susceptible and resistant P. xylostella, five different populations of P. xylostella were compared in insecticide susceptibilities and parasitism by C. plutellae. These five P. xylostella populations showed a significant variation against three commercial insecticides including pyrethroid, organophosphate, neonicotinoid, and insect growth regulator. However, there were no significant differences among five P. xylostella populations in their parasitic rates by C. plutellae. Moreover, parasitized larvae of P. xylostella showed significantly higher susceptibility to B. thuringiensis. As an immunosuppressive agent, viral ankyrin genes (vankyrins) encoded in C. plutellae were transiently expressed in nonparasitized larvae. Expression of vankyrins significantly enhanced the efficacy of B. thuringiensis against the third instar larvae of P. xylostella. Thus an immunosuppression induced by C. plutellae enhanced the insecticidal efficacy of B. thuringiensis. These results suggest that a combined treatment of C. plutellae and B. thuringiensis may effectively control the insecticide-resistant populations of P. xylostella.

• Korean Journal of Plant Taxonomy
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• v.43 no.4
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• pp.252-262
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• 2013

During the floristic survey on Phnom Bokor National Park, Kampot, Cambodia, we encountered Balanophora fungosa var. indica, which is a tropical holoparasitic plant. To identify its host species, we collected host roots and trees nearby and tried to identify them using DNA barcoding approach. We applied plastid rbcL and matK gene regions as DNA barcode markers, and successfully amplified and sequenced the markers from 15 host roots and seven tree samples. Obtained host root sequences were identified as Primulaceae, Celastraceae, Myrtaceae, and Oleaceae, while trees nearby are Oleaceae, Myrtaceae, Sapindaceae, Rosaceae, Clusiaceae, Ericaceae, and Lauraceae. At genus level, host species are identified as Myrsine, Euonymus, Syzygium, and Olea, but failed in species discrimination. Myrsine (Primulaceae) and Olea (Oleaceae) are reported here as host species of B. fungosa var. indica for the first time. Further sampling and comparative work, and DNA barcoding will help recognize the biodiversity of the area and host species of Balanophora, together with their evolution.

• Korean journal of applied entomology
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• v.47 no.4
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• pp.467-472
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• 2008

During the survey of plant parasitic nematode of Citrus orchard in Korea, Paratrichodorus minor (Colbran, 1956) Siddiqi is founded from the soil of Citrus unshiu Markovich for the first time in Korea. The body length of females is $428.34{\sim}506.22{\mu}m$ long: a = $12.08{\sim}22.79$, b = $4.02{\sim}5.02$, V(%) = $38.46{\sim}60.68$. The excretory pore is located near the base of esophagus. Additionally, the morphological characteristics on P. porosus (Allen, 1957) Siddiqi, 1974 recorded in 1976 on Korea is redescribed in detail.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1449-1453
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• 2008

Galla Rhois is a nest of parasitic bug, has been traditionally used for the treatment of the therapy of diarrhea, peptic ulcer, hemauria, etc., that showed various anti-inflammatory activity, and other biological properties. We studied the effect of Galla Rhois ethanol extract. we investigated whether compounds isolated from the ethanol extract of Galla Rhois, could modulate iNOS and COX-2 expression in RAW 264.7 macrophages stimulated with lipopolysaccharide (LPS). We found compounds that suppressed LPS-induced iNOS and COX-2 expression. Suppression of the expression of iNOS and COX-2 was in parallel with the comparable inhibition of the production of nitric oxide (NO) and prostaglandin E2 (PGE2). Our results suggest that compounds can inhibit NO and PGE2 productions through suppression of LPS-induced iNOS and COX-2 expression. Because COX-2- or iNOS-dependent mechanisms are involved in inflammation and tumor progression, our findings provide a new uncovering mechanism responsible for anti-inflammatory and antitumor effects of Galla Rhois.

• Journal of Forest and Environmental Science
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• v.33 no.2
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• pp.105-112
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• 2017

The distribution and form of pine wood nematode (PWN) were investigated in Jinju-si and Sacheon-si areas, where infested with pine wilt disease (PWD). The average PWN population per g of the tubulation part in the wilted Japanese balck pine were 381.2 and 341 in Jinju-si and Sacheon-si, respectively. The PWN population per g of affected Japanese black pine with wilt rate below 60% were 556 and 518 in Jinju-si and Sacheon-si, respectively. The ratios of PWN and other plant-parasitic nematode in the wilted Japanse black pines were 48% vs. 52% in Jinju-si and 53% vs. 47% in Sacheon-si after exposure to PWD for 1 year. The survivorship of pine wood nematode in the sampled trees after 1 year was 0-10% in the Jinju-si area and 5-20% detected in the Sacheon-si area. In the forest areas affected by PWN, the highest survival rates were 37.2% and 39.8% at 25 cm diameter at breast height (DBH) in Jinju-si and Sacehon-si, respectively, while the highest wilt rates were 30.5% and 28.3% at 30 cm DBH in Jinju-si and Sacehon-si, respectively.

• Korean journal of applied entomology
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• v.39 no.2
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• pp.111-115
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• 2000

Fifty-two nematode predatory fungi were isolated from 37 soil samples collected from eight provinces in Korea. Isolated fungi were tested their predacity against Rhabditis sp. and Meloidogyne incognita in petri dish, and against M. incognita in greenhouse pot experiments. Fifty isolates had trapping organ of adhesive networks and two isolates had adhesive column or adhesive knob. In petri dish experiments, 5 1 isolates against Rhubditis sp. and 26 isolates against M. incognita showed over 91 % of predacity; in greenhouse experiments, however, only three isolates showed over 81% of predacity. These results imply that the results from the laboratory experiments are not consistent with those from the greenhouse experiments. Therefore, to select a promising biocontrol predatory fungi for plant-parasitic nematodes, the screening experiment should be conducted in conditions close to nature.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.423-439
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• 2022

The acute dermal and eye irritation tests of Photorhabdus temperata, a symbiotic bacterium of Heterorhabditis megidis Gwangju strain, were carried out in New Zealand white rabbit (Oryctolagus cuniculus), following the guidelines of OECD and Rural Development Administration (RDA) of Korea. In both tests, neither dermal nor eye responses were found from all the P. temperata treated rabbits and the results were classified as non-irritating. That is, erythema, eschar, edema, and any other dermal critical signs were not observed from all the experimental rabbits in the dermal irritation test. In the acute eye irritation test, no clinical signs of cornea, iritis, conjunctiva (redness, edema, lacrima, and chemosis) were observed from all the experimental rabbits. Individual ocular irritation, mean ocular irritation, and acute ocular irritation were calculated as 0.0. The results of dermal and eye irritation studies on P. temperata indicated that this bacterium could be a safe and effective alternative bionematicide against the most serious plant-parasitic root-knot nematodes in the genus Meloidogyne.

• The Plant Pathology Journal
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• v.17 no.5
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• pp.257-263
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• 2001

Species of the genus Orobanche are parasitic flowering plants, holoparasites, which cling to the roots of green plants. Their tiny seeds (200 x $250\mu\textrm{m}$) germinate in response to chemical stimuli produced by host and some non-host plants. Successful contact with their host leads to development of haustoria for obtaining water and food. The shoots above the ground expose flowers and disseminate seeds. Several samples of Orobanche ramosa, O. crenata, O. cernua, and O. egyptiaca were collected from different localities in Jordan. These samples showed one of the following disease symptoms: dry rot at the base of the stem; general deterioration and expanded lesion from base upward; soft tissue maceration of stem; and black rot of flower parts with incomplete maturation of the ovary and seeds. Isolation from diseased stems and seeds was made on three different mycological media. Several fungi were isolated, mainly, Fusarium spp., Alternaria alternata, Rhizoctonia sp., Dendrophora sp., Chaetomium sp., and an ascomycetus fungus with a perithecium. Pathogenicity tests showed that Fusarium spp. and Alternaria alternata attacked healthy living tissue of Orobanche spikes. These fungi caused lesions of black soft rot and complete deterioration within 5-7 days. They also attacked Orobanche seeds, arresting their germination and causing maceration of non-germinated and germinated seeds after 5-7 days of incubation. Meanwhile, Dendrophora sp. and Chaetomium sp. caused limited lesion at first, but were able to colonize the tissue as it aged and senesced. This study showed the presence of a potential endogenous pathogenic fungi in Jordan, which can be investigated as a biological control for Orobanche.