• Korean journal of applied entomology
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• v.55 no.4
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• pp.377-381
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• 2016

The Baermann funnel method requires approximately four Kimwipe tissues for research a nematode count under a stereo microscope. To select more efficient and economical nematode extraction paper for nematode extraction, 15 different kinds of tissue papers were tested and compared with Kimwipe tissues. Nematode species used in the extraction efficiency tests include juvenile (J2) of Heterodera sp., J2 of Meloidogyne sp., Pratylenchus sp., Rhabditis sp., Acrobeloides sp., Panagrolaimus sp., Poikilolaimus sp. and Diplogasterida. The extraction efficiency varied between 42.0 to 88.8%. Considering costs, extraction efficacy, and clarity, the Pulling Kitchen Towel (Monalisa Co., Korea) is the best tissue, with clarity A, isolation efficiency of 69.4% (not significantly different compared to Kimwipe 1 ply 88.8%), and 1/2 costs per isolation of Kimwipe 2 ply.

• Korean journal of applied entomology
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• v.24 no.1 s.62
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• pp.39-44
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• 1985

This study was undertaken to select a suitable Korean tissue paper for Baermann funnel method. Ten kinds of five manufacturers were evaluated as to nematode extraction efficiency in Baermann funnel. 'Crown Hankie'(Korea Special Paper Co., Ltd.) had suitable properties in nematode permeability and strength regardless of three soil types, loamy sand, sandy loam and clay loam. The number of nematodes extracted using 'Crown Hankie' 4 ply was 198, while that of 'Cottonwool Nematode Filter' was 227. Un-perfumed tissue papers showed higher nematode extraction efficiencies than perfumed tissue papers by 53 and 23% in 'Kleenex New Softness' and 'Monaliza Finely Soft Tissue', respectively. Among the nematode extraction efficiencies by temperatures, $15^{\circ},\;25^{\circ}\;and\;35^{\circ}C$, it was highest at $35^{\circ}C$. In experiment of evaluating nematode extraction using Baermann funnel at 12 hours interval to 92 hours, 35.3 and 40.3% of nematodes were extracted after 12 and 24 hours, respectively.

• Korean journal of applied entomology
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• v.53 no.2
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• pp.141-147
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• 2014

Pinewood nematode (PWN: Bursaphelenchus xylophilus) is known to kill pine tree species that are indigenous to countries where the pest was inadvertently imported, but some cultures from the extraction of dead pines do not damage trees. Experiments were conducted to examine the effect of pre-inoculation of these low-pathogenic pinewood nematode on resistance of pine trees against the pest species. The pre-inoculated pine saplings showed induced resistance which lasted for a year, and repeated inoculation of these low-pathogenic nematodes enhanced tree resistance. All nematode samples extracted from dying or dead pines that had been killed not more than three months before the extraction were pathogenic, and most of those extracted from pines that had been killed 2-3 years before were low-pathogenic. When inoculated in pine saplings, number of low-pathogenic nematodes settled, as studied two days after inoculation, was not different from that of pathogenic ones. However, as studied after 30 days of inoculation, rate of reproduction in low-pathogenic nematodes was far lower than that of pathogenic nematodes. The rate of reproduction of several nematode isolates growing on fungal mat media of Botrytis cinerea varied, but three of four low-pathogenic isolates showed same level of reproduction rates as pathogenic ones.

• The Plant Pathology Journal
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• v.33 no.2
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• pp.184-192
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• 2017

Tylenchulus semipenetrans is an important and widespread plant-parasitic nematode of citrus worldwide and can cause citrus slow decline disease leading to significant reduction in tree growth and yield. Rapid and accurate detection of T. semipenetrans in soil is important for the disease forecasting and management. In this study, a loop-mediated isothermal amplification (LAMP) assay was developed to detect T. semipenetrans using DNA extracted from soil. A set of five primers was designed from the internal transcribed spacer region (ITS1) of rDNA, and was highly specific to T. semipenetrans. The LAMP reaction was performed at $63^{\circ}C$ for 60 min. The LAMP product was visualized directly in one reaction tube by adding SYBR Green I. The detection limit of the LAMP assay was $10^{-2}J2/0.5g$ of soil, which was 10 times more sensitive than conventional PCR ($10^{-1}J2/0.5g$ of soil). Examination of 24 field soil samples revealed that the LAMP assay was applicable to a range of soils infested naturally with T. semipenetrans, and the total assay time was less than 2.5 h. These results indicated that the developed LAMP assay is a simple, rapid, sensitive, specific and accurate technique for detection of T. semipenetrans in field soil, and contributes to the effective management of citrus slow decline disease.

• Parasites, Hosts and Diseases
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• v.48 no.3
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• pp.259-261
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• 2010

Human Gnathostoma hispidum infection is extremely rare in the world literature and has never been reported in the Republic of Korea. A 74-year-old Korean man who returned from China complained of an erythematous papule on his back and admitted to our hospital. Surgical extraction of the lesion and histopathological examination revealed sections of a nematode larva in the deep dermis. The sectioned larva had 1 nucleus in each intestinal cell and was identified as G. hispidum. The patient recalled having eaten freshwater fish when he lived in China. We designated our patient as an imported G. hispidum case from China.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.315-324
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• 2011

The nematicidal and egg haching inhibitory effects of extracts from 30 herbal plants (total 32 samples) against Meloidogyne hapla J2 juveniles and eggs was tested using the dipping method. At 1,000 ppm, extracts of Daphne genkwa flower buds, Eugenia caryophyllata flowers, Quisqualis indica fruits, and Zingiber officinale rhizomes produced > 80% mortality in J2 juveniles. At 125 ppm, extracts of D. genkwa and Q. indica produced 91 and 99% mortality, respectively. The toxicity of 5 selected plant extracts to M. hapla differed depending on the solvent used (i.e. hexane, methanol, hot water, or cold water). Hot water extracts of Z. officinale and Q. indica produced nematicidal efficacies of 99 and 99%, compared to 36 and 98%, respectively, with cold water extraction. Q. indica extract was highly active against M. hapla regardless of extraction method. The inhibitory effects of Areca catechu, D. genkwa, Desmodium caudatum, Pharbitis nil, Q. indica, and Z. officinale extracts on egg hatching of M. hapla was evaluated. At 1,000 ppm, D. genkwa, P. nil, and Q. indica extracts significantly reduced hatching at 7, 14 and 21 days after treatment. Numbers of juveniles in soil treated with the methanol extract D. genkwa (1,000 ppm) were significantly lower than in untreated soil in trials in pots and in a ginseng (Phanax ginseng) field. These results indicate that Q. indica extracts could be used as an environmental friendly control agent of M. hapla.

• Research in Plant Disease
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• v.21 no.2
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• pp.50-57
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• 2015

Control of nematode has become difficult owing to the restricted use of effective soil fumigant, methyl bromide, and other non-fumigant nematicides. Therefore, it is urgently necessary to develop microbial nematicide to replace chemical nematicides. In this study, the 50% aqueous methanol extraction solution of fermentation broths of 2,700 actinomycete strains were tested for their nematicidal activity against second stage of juveniles (J2s) of Meloidogyne incognita. As the results, only the 50% aqueous methanol extraction solution of AN110065, at 20% equivalent to 10% fermentation broth, showed strong nematicidal activity with 78.9% of mortality 24 h after treatment and 94.1% of mortality at 72 h. The 16S rRNA gene sequencing showed that the strain sequence was 99.78% identical to Streptomyces netropsis. The extract of S. netropsis AN110065 fermentation broth was successively partitioned with ethyl acetate and butanol and then the ethyl acetate, butanol and water layers were investigated for their nematicidal activity against the M. incognita. At $1000{\mu}g/ml$, ethyl acetate layer showed the strongest activity of 83.5% of juvenile mortality 72 h after treatment. The pot experiment using the fermentation broth of AN110065 on tomato plant against M. incognita displayed that it evidently suppressed gall formation at a 10-fold diluent treatment. The tomato plants treated with the fermentation broth of S. netropsis AN110065 did not show any phytotoxicity. The results suggest that S. netropsis AN110065 has a potential to serve as microbial nematicide in organic agriculture.

• The Korean Journal of Mycology
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• v.1 no.1
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• pp.3-11
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• 1973

Four species of nematodes attacking mushroom beds were found in samples taken from 35 mushroom farms throughout Korea. These were Rhabditis sp., Aphelenchoides sp., Ditylenchus sp. and Aphelenchus sp. ,Rhabditis sp. was found from compost and casing from all mushroom farms and the frequencies of Aphelenchoides sp. was 31.4% in the both compost and casing. Both Ditylenchus sp. and Aphelenchus sp. showed 2.7% of frequencies in the compost, none in casing. Temperature and moisture content of compost affected pathogenicity of Aphelenchoides sp. on mushroom mycelia grown in compost. The higher temperature and moisture content the sooner the damage became apparent, and the more rapid was subsequent destruction of mycelia. There was no mycelial destruction at the lowest temperature of $10^{\circ}C$. Rhabditis sp. completely disintegrated mycelia grown in the compost, in the early stage, the numbers of Rhabditis sp. rose gradually and then increased suddenly to reach a peak but soon declined. At first, the pH of Rhabditis-infested spawned compost declined but then rose gradually as mycelia was disintegrated by nematodes. The trend in pH of infested unspawned compost was similar to those of uninfested, unspawned compost. Cultures inoculated with surface-disinfected dead Rhabditis sp. and with tap water used in the nematode extraction procedures showed no mycelial injury associated microorganisms containing within or outside the nematodes even though added by artificial wounding of the mycelia. Cultures artificially wounded showed no injury away from the wounds without the presence of living Rhabditis sp., such wounded mycelia slowly regenerated. On the other hand, artificial wounding accelerated the breakdown of mycelia in the presence of living Rhabditis sp.