• Research in Plant Disease
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• v.22 no.4
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• pp.243-248
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• 2016

As preventive measures for bonsai exports, nematodes were isolated from 55 bonsai samples of five coniferous species (Chamaecyparis pisifera, Juniperus chinensis, Pinus densiflora, Pinus thunbergii, and Taxus cuspidate) from all 15 bonsai gardens in Korea. Nematodes belonging to 21 genera in 7 orders were isolated from the 55 bonsai samples. Among plant-parasitic nematodes, Tylenchus spp. was the most frequently isolated (14.9%), followed by Ditylenchus spp. (10.5%), Aphelenchoides spp. (9.5%), Aphelenchus sp. (5.5%), Criconemoides sp. (4.0%), Helicotylenchus sp. (0.7%), Hemicycliophora sp. (0.7%), Mesocriconema sp. (0.7%), Tylenchorhynchus sp. (0.7%), and Paratylenchus sp. (0.4%). Among nonparasitic nematodes, Cephalobina was the most frequently isolated nematodes (26.5%), followed by Rhabditida (19.3%), Dorylaimida (17.8%), Pangrolaimida (14.5%), Plectida (6.5%), Tryphylida (6.2%), Mononchida (3.3%), Alaimida (2.9%), Monhysterida (2.5%), and Triplonchida (0.4%). Based on these results, we conclude that there is no problematic plant-parasitic nematode in bonsai gardens of Korea.

• Ocean Science Journal
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• v.42 no.3
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• pp.165-170
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• 2007

The structure of the nematodes communities has been studied in the sediments on two sites located outside and under the layer of Ahnfeltia tobuchiensis (Kanno and Matsubara 1932; Makijenko 1970). Bottom sediments at the stations were represented by sands with a different degree of silting. Specific structure of nematodes at the stations was significantly different under the similar environmental conditions (water depth, dissolved oxygen saturation, salinity, temperature of the bottom layer and organic carbon content inside of the sediment). Nematodes dominated (75.7 %) in meiobenthos community under the layer of A. tobuchiensis where concentration of silt particles was 12 %. Representatives of the family Comesomatidae were dominant. Low index of species diversity and high Simpson domination index were detected in this community. Under a layer of A. tobuchiensis with the thickness of 30 cm concentration of the silt particles was 5.39 %; nematodes density was low and made 32.1 % of the general density of meiobenthos. Species of the families Xyalidae and Monoposthiidae were dominant. Outside of A. tobuchiensis, field percentage of silt particles was minimal (3.1 %) and representatives of families Cyatholaimidae and Axonolaimidae dominated. The specific structure of nematodes in this type of the ground is characterized by high index of species diversity and low level of domination.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.139-143
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• 2001

The efficacies of several entomopathogenic nematodes of Steinernema and Heterorhabditis spp. were examined against tobacco cutworm, Spodoptera litura Fabricius. H. bacteriophora HY showed 100% mortality after 20 h against 2nd instar of tobacco cutworm. In the case of 3-4th instar, S. carpocapsae PC, H. bacteriophora HY and S. monticola CR showed 100% mortality after 47 h. In the case of 5-6th instar, S. carpocapsae PC proved more effective than the others. Generally, the number of nematodes harvested as their size decreased. Also, the highest number of nematodes was obtained in the 5-6th instar of S. litura by H. bacteriophora HY, showing about $1.3{\times}10^6$ nematodes per larva. In vitro cultured S. carpocapsae PC showed 100% mortality after 73 h against 5-6th instar tobacco cutworm, indicating that nematodes produced in vitro can be potentially used for the biological control of S. litura instead of nematodes in vivo.

• Research in Plant Disease
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• v.29 no.1
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• pp.45-51
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• 2023

The study was conducted to investigate the infestation and distribution of plant-parasitic nematodes on kiwi orchards in Korea. Plant parasitic nematodes genus and densities were investigated at a total of 102 sites in Jeollanam-do, Gyeongsangnam-do, and Jeju-do, which are the main production areas of domestic kiwi orchards. Plant parasitic nematodes detected were of 9 genera, including root-knot nematodes (Meloidogyne spp.), spiral nematodes (Helicotylenchus spp.), and needle nematodes (Paratylenchus spp.), and 56% of the 102 plantations were infected with root-knot nematodes. Root-knot nematodes were found to be the most important plant parasitic nematode in domestic kiwi orchards. The average density of root-knot nematodes is 97 per 300 cm³ soil, and there is concern about the kiwi yield reduction. As a result of identifying the root-knot nematode species: M. arenaria, M. hapla, M. incognita, and M. javanica. Among them, M. arenaria is the most dominant. As the plant parasitic nematode infection route in fruit trees is often spread through the transplantation of infected seedlings, attention should be paid to the production of nematode-free plants during the production and supply of kiwifruit plants.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 1994.06a
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• pp.62-74
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• 1994

The current status of the development of commercial products for the biological control of plant-parasitic nematodes is discussed. an example is given of problems encountered by our program in patenting biocontrol agents in the United Stats. Two hypothetical approaches to the control of plant nematodes are considered. First recent experimental results relating to the theory on intervention with host-finding by plant nematodes are reviewed. Second, a newer hypothesis considering the possibilities for genetic approaches to modifying molecular signals between nematodes and their parasites is described.

• Korean Journal of Plant Resources
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• v.37 no.4
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• pp.314-320
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• 2024

To speed up the extract of endoparasitic nematodes from roots, four extraction methods with or without root-grinding were compared; 1) immersion, 2) immersion + Air, 3) Oostenbrink dish, and 4) Mistifier. The experiments were conducted for nine days by using perilla roots infested with Pratylenchus vulnus. Root-lesion nematodes continuously extracted from perilla roots during the experiments and as much as 3-10% in 9^th days. The total number of nematodes extracted from 2 g of perilla root in nine days were varied among methods (379-1,824 nematodes); the most nematodes were extracted by root grinding + immersion + air (1,824) and the root-grinding + mistifier method (1,349) (p = 0.05). In the first two days of extraction, root-grinding + mistifier extracted the most nematodes (725 nematodes), followed by root-grinding + immersion + Air (555 nematodes), and root-grinding + Oostenbrink dish (421 nematodes). Root-grinding effected as much as 16-108% more nematodes extraction when compared to without root-grinding (p = 0.01).

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.1
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• pp.74-78
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• 2012

Envioronmental concerns by use of chemical pesticides have increased the need for alternative method in the control of plant-parasitic nematodes. Biological control is considered eco-friendly and a promising alternative in pest and disease management. A wide range of organisms are known to be effective in control of plant-parasitic nematodes. Fungal biological control is a hopeful research area and there is constant attention in the use of fungi for the control of nematodes. In this review, plant-parasitic nematodes with reference to soils and biological control and nematophagous fungi are dicussed.

• Korean Journal of Environmental Biology
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• v.39 no.2
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• pp.147-155
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• 2021

To investigate the incidence of plant-parasitic nematodes (PPNs) in perilla fields in Korea, 55 soil samples were collected from open fields and plastic-film house fields and were analyzed during January 2020 to October 2020. Root-lesion nematodes (RLNs), spiral nematodes, root-knot nematodes, and stunt nematodes were detected in perilla fields, and the incidences of RLNs (39%) and spiral nematodes (55%) were higher than those of other nematodes. Among PPNs, RLNs are very important species found on economic crops. The detection frequency of RLNs was increased due to continuous crop cultivation, and the frequency of fields that cultivated only one crop continuously for over 11 years was twice higher than the frequency of fields that cultivated only one crop for less than 5 years. The PPN species diversity and density were different between leaf-perilla cultivation fields and seed-perilla cultivation fields. In phylogenetic analysis of RLNs, Pratylenchus penetrans, P. vulnus, and Pratylenchoides leiocauda were identified in perilla fields. These results suggest the RLNs should be considered for establishing nematode management strategies in perilla fields in Korea.

• Fisheries and Aquatic Sciences
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• v.19 no.5
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• pp.26.1-26.8
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• 2016

Background: The nematode species belonging to genus Anisakis occur at their third larval stage in numerous marine teleost fish species worldwide and known to cause accidental human infection through the ingestion of raw or undercooked fish or squids. They may also draw the attention of consumers because of the visual impact of both alive and dead worms. Therefore, the information on their geographical distribution and clear species identification is important for epidemiological survey and further prevention of human infection. Results: For identification of anisakid nematodes species isolated from largehead hairtail (Trichiurus japonicus), polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of internal transcribed spacers of ribosomal DNA were conducted. Mitochondrial cytochrome c oxidase subunit 2 gene was also sequenced, and phylogenetic analysis was conducted. From the largehead hairtail (n = 9), 1259 nematodes were isolated in total. Most of the nematodes were found encapsulated throughout the viscera (56.2 %, 708/1259) or moving freely in the body cavity (41.5 %, 523/1259), and only 0.3 % (4/1259) was found in the muscles. By PCR-RFLP, three different nematode species were identified. Anisakis pegreffii was the most dominantly found (98.7 %, 1243/1259) from the largehead hairtail, occupying 98.7 % (699/708) of the nematodes in the mesenteries and 98.1 % (513/523) in the body cavity. Hybrid genotype (Anisakis simplex ${\times}$ A. pegreffii) occupied 0.5 %, and Hysterothylacium sp. occupied 0.2 % of the nematodes isolated in this study. Conclusions: The largehead hairtail may not significantly contribute accidental human infection of anisakid nematode third stage larvae because most of the nematodes were found from the viscera or body cavity, which are not consumed raw. But, a high prevalence of anisakid nematode larvae in the largehead hairtail is still in concern because they may raise food safety problems to consumers. Immediate evisceration or freezing of fish after catch will be necessary before consumption.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.10
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• pp.51-56
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• 1971

To make certain of the white tip infection on rice, nematodes isolated from the rice seeds grown at Chongdo-goon Isu-myun and Kimje-goon Chooksan-myun were artificially inoculated and their pathway was studied. Also, studies were made for the hot water seed treatment as a measure of white tip control at different levels of water temperature and their germinablity was checked. The results are summarized as follows; 1. Causal nematodes survive in the paddy soil and cause white tip year after year. 2. Causal nematodes can survive in the rice seeds as long as the seeds loose their germinability. 3. Causal nematodes can disseminate throught the irrigation water. 4. Causal nematodes can disseminate through the soil move from a place to other place. 5. Causal nematodes can infect all of the parts of the rice and they can disseminate through any of the parts of rice. 6. The hot water treatment at 5$0^{\circ}C$ for 60 minutes were not effective controlling causal nematodes. But, either treatment of at 55$^{\circ}C$ for 15-20 minutes or at 6$0^{\circ}C$ for 10-15 minutes were effective and germination of seeds was not affected.