• The Plant Pathology Journal
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• 제26권2호
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• pp.149-153
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• 2010

Biological and structural mechanisms of the nematode disease development in chili pepper caused by the root-knot nematode, Meloidogyne incognita, were investigated. Out of 39 chili pepper cultivars/lines tested, six were found resistant, while 33 were susceptible to M. incognita, of which a susceptible cultivar Chilseongcho and three resistant cultivar/lines CM334, 02G132 and 03G53 with different resistance degrees were selected for microscopic studies on the disease development. Gall formation was greatly reduced in the resistant cultivars/lines. Nematode penetration occurred both in the susceptible and resistant chili pepper roots; however, the penetration rates were significantly lowered in the three resistant peppers compared to the susceptible pepper cv. Chilseongcho. In the susceptible pepper, giant cells were extensively formed with no discernible necrosis around the nematode feeding sites. In the highly resistant pepper cultivar CM334, no giant cell was formed, but extensive necrosis formation was observed around the penetrating nematodes. In the other two resistant pepper lines (02G132 and 03G53), both giant cells and prominent necroses were formed, and the necrotic responses appeared to inhibit the further development of giant cells or accelerate their early degeneration. Although the nematode penetration was retarded significantly in the resistant cultivar/lines, all of the above results suggest that the disease resistance of pepper may be related to post-infectional defense mechanisms (nematode growth and development) more than pre-infectional ones (penetration and establishment). Variations in structural modifications in the resistant cultivar/lines may reflect their genetic differences related to the nematode resistance.

• 한국균학회지
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• 제9권4호
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• pp.193-197
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• 1981

1) 인삼(人蔘)밭 토괴(土壞)중에서 nematode-destroying fungi에 속하는 6균주의 Arthrobotrys sp.와 세균주(菌株)의 Harposporium sp.를 분리(分離), 동정(同定)하였다. 2) Arthrobotrys sp.는 선충(線蟲)이 존재(存在)하는 곳에서는 포획(捕獲)기관을 형성(形成)하였으나, 선충(線蟲)이 없는 곳에서는 포획(捕獲)기관을 형성(形成)하지 않았다. 3) Arthrobotrys sp.는 nutrient agar와 malt extract agar에서 매우 잘 생장(生長)하였다.

• The Plant Pathology Journal
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• 제25권2호
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• pp.189-192
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• 2009

The effect of plant extracts of eucalyptus (Eucalyptus chamadulonsis), garlic (Allium sativium), marigold (Tagetes erecta) and neem (Azadirachta indica) and essential oils were tested on the suppression of root-knot nematode Meloidogyne incognita under greenhouse and field conditions. In vitro study, all tested treatments had nematicidal effect on nematode juveniles after 24 and 48 hours from exposures. The highest percentage of nematode mortality was achieved by application of neem extract (65.4%), essential oils (64.4%) and marigold extract (60.5%), followed by garlic and eucalyptus extracts (38.7-39.5%). Under greenhouse and field conditions, neem extract and essential oils treatments were more effective in reducing population numbers of the M. incognita in soil and root gall index compared to other treatments. In field experiments, the maximum protection of tomato plant against root-knot nematode was obtained by application of neem and essential oil treatments, 44.2 and 32.6%, respectively.

• 한국식물병리학회지
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• 제10권4호
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• pp.319-324
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• 1994

The monoxenic culture of the fungivorous nematode, Aphelenchus avenae, was applied for the control of soil-borne ginseng pathogens such as Fusarium solani and Rhizoctonia solani. Fungivorous nematode populations were measured in a field to examine relationships between the nematode populations and suppression of ginseng root diseases. Inoculation of A. avenae (5000 nematodes per petri-dish) reduced the colonization of the Fusarium mycelium on root discs of ginseng and carrot by 80.0% and 60.5%, respectively. A. avenae also significantly reduced the occurrence of damping-off of ginseng by R. solani pathogenic to ginseng, and no plant damage by the nematode was noted. In a 3-year-old ginseng field infested with Cylindrocarpon destructans, plant missing caused by root rot positively correlated to the density of potato rot nematode, Ditylenchus destructor, but it was reduced with the population of A. avenae, suggesting that A. avenae might inhibit the occurrence of ginseng root rot.

• 식물병연구
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• 제14권1호
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• pp.76-78
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• 2008

포항지역의 부추 연작 장해를 조사하는 중 부추에서는 처음으로 뿌리혹선충의 기생이 발견하여 보고한다. 부추에 기생하는 뿌리혹선충은 Meloidogyne incognita로 동정되었다. 연작 장해지에는 뿌리혹선충, 뿌리응애(Rhizoglyphus sp.), 시들음병(Fusarium oxysporum f. sp. cepae)등이 복합적으로 발생되고 있었지만 발생 빈도와 피해 정도를 보아 연작장해의 주요 원인은 뿌리혹선충이었다.

• 한국유기농업학회지
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• 제19권spc호
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• pp.267-270
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• 2011

Root-knot nematodes cause a significant damage on fruit yield and quality of green house growing crops. To asses the effect of eggplant rootstock, Torvum vigor', TaibyouVF' and 'Daitaro' were grafted on eggplants(Solanum melongena cv. Chookyang) and planted in root-knot nematode infested microplot in green house and compared their fruit yield, quality and plant growth with non-grafted control. Eggplant grafted with Torvum vigor had the highest fruit yield and top growth and followed by Daitaro. Non-grafted eggplant had lower yield but had higher root weight because of heavy root-knot nematode infection. Rootstock grafting in eggplant farming is a good alternative technique in root-knot nematode infested green houses without compromising fruit yield and can be applied instantly as organic farming practice.

• 미생물학회지
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• 제22권1호
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• pp.19-28
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• 1984

A. conoides에 의한 선충 포획과정을 SEM과 TEM을 이용하여 관찰하였다. 1. A. conoides는 점착성 three-dimensional networks에 의해 선충을 포획한다. 2. Trap cell은 영양균사에 비해 세포벽이 두꺼우며 endoplasmic reticulum, mitochondria 및 electron-dense granule이 풍부하다. 3. 포획기관에서만 관찰되는 전자밀도가 높은 과립은 포획기관이 선충을 점착하여 침투하는 과정에서 소실된다. 4. 포획기관과 선충이 부착된 사이에서 osmiophilic layer가 관찰되었고 바로 이 지점으로부터 침투가 일어나며, 한 포획기관에서 두 군데 이상 동시 침투가 가능하다. 5. 포획기관의 선충내 침투시 appressorium이 형성되지 않고 침투되는 경우가 있다. 6. 균주와 선충의 혼합배지를 2~3주 두었을 때, 유충들이 포자에 접착되어 죽는다.

• Journal of Crop Science and Biotechnology
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• 제11권3호
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• pp.177-180
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• 2008

Worldwide, cyst nematode(Heterodera glycines Ichinohe) is the most destructive pathogen of cultivated soybean. In the USA, current annual yield losses are estimated to be nearly a billion dollars. Crop losses are primarily reduced by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars over time because resistance primarily traces to two soybean accessions. It is important to use diverse resistance sources to develop new nematode resistant cultivars. Soybean PI 494182 is a recent introduction from Japan and found to be resistant to multiple nematode populations. It is yellow seeded and maturity group 0. We have determined inheritance of resistance in PI 494182 using $F_{2:3}$ families derived from cross PI 494182 X cv. Skylla. Skylla is a susceptible parent. Three nematode populations, races 1, 3, and 5, corresponding to HG types 2.5.7, 0, and 2.5.7 were used to bioassay 162 $F_{2:3}$ families in greenhouse experiments. Based on Chi-square tests, a two-gene model is proposed for resistance to race 1 and a three-gene model is proposed for conditioning resistance to both races 3 and 5. Correlation coefficient analysis indicated that some genes conditioning resistance to races 1, 3, and 5 are shared or closely linked with each other. These results will be useful to soybean breeders for developing soybean cultivars for broad resistance to nematodes.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• 제3권4호
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• pp.221-226
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• 2022

A filarial nematode was found in a blood sample of an Anas falcata individual collected in South Korea in 2018. Phylogenetic analysis based on partial cytochrome C oxidase subunit I (COI) sequences placed the nematode as a novel genus of the family Onchocercidae and as closely related to Mansonella species, Chandlerella quiscali, and filarial nematodes recently reported in avian species. However, different phylogenetic relationship was observed in the NADH dehydrogenase subunit 5 and 12S rRNA-based phylogenetic trees, which might indicate the filarial nematode found in this study was not defined to belong to the known specific genera of the family Onchocercidae. The screening of 105 additional avian blood samples retrieved only one 12S rRNA-targeting polymerase chain reaction (PCR)-positive sample, which indicates that filarial nematode infection is rare in wild birds or that it occurs below the detection limit of PCR in blood samples. Nevertheless, considering the recent findings about ancient interactions between birds and human pathogenic filarial nematodes and their pathogenic potential in several avian species, additional exploration of novel filarial nematodes in wild birds remains necessary.

• 한국토양동물학회지
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• 제1권2호
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• pp.81-88
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• 1996

Entomopathogenic nematodes, Steinernema carpocapsae, was able to invade and kill the several lepidopteran pests including the beet armyworm, Spodeptera exigua Hubner, which was the most effective target host. The beet armyworms treated with the effective nematode concentrations were died within 48 hrs. The lethal effect of the nematode was varied among the developmental stages of the host. The fifth instar larvae of the beet armyworm was more vulnerable to the nematode than the third instar larvae. Pupae was, however, refractory to the nematode. All three bioessays (topical application, filter paper test, and soil treatment) showed the positive correlation between the number of the treated nematodes and the mortality of the host. Topical application was the most effective and fast-acting method so that it gave the lethal effect 2 days earlier than did filter paper test at the same number of the treated nematodes. Soil treatment required higher number of the nematodes to get the effective lethality than did filter paper test. The fifth instar larvae of the beet armyworm expressed the specific hemolymph proteins of 5 to 10 kDa in response to nematode infection.