• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.162-168
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• 2012

An nematophagous fungi Arthrobotrys thaumasia Nema-1 and Bacillus subtilis C-9, which degrade the collagen and gelatin, were isolated from horticulture plantation soil in Kyungpook Sungju-gun Seonnam-myun and Chungnam Gongju-gun Woosung-myun to develop biological nematode pesticide. When $5,000mg\;kg^{-1}$ of A. thaumasia Nema-1 nematicide powder ($7.0{\times}10^3cfu\;g^{-1}$) was treated to pot including Meloidogyne incognita, the number of nematode's egg mass, which is a index of nematicidal activity, decreased to 35% compared to control. While the number of nematode's egg mass decreased to 67% by treating the nematicide powder mixture of $5,000mg\;kg^{-1}$ Nema-1 and B. subtilis C-9 ($8.5{\times}10^5cfu\;g^{-1}$). Furthermore the number of nematode's egg mass of the mixture containing cinnamon extract $10mg\;kg^{-1}$, each $5,000mg\;kg^{-1}$ of Nema-1 and C-9 nematicide powder was decreased to 84%, comparing to the result showed the number of nematode's egg mass decreased to 24%, by the treatment of chemical nemato pesticide Fosthiazate $24mg\;kg^{-1}$. These results suggested the mixture of microorganisms and plant extract was more effective biological nematicide than the case of only microorganism or plant extract for nematode control.

• The Plant Pathology Journal
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• v.34 no.3
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• pp.241-249
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• 2018

Commercial biocontrol of microbial plant diseases and plant pests, such as nematodes, requires field-effective formulations. The isolate Pseudomonas chlororaphis O6 is a Gram-negative bacterium that controls microbial plant pathogens both directly and indirectly. This bacterium also has nematocidal activity. In this study, we report on the efficacy of a wettable powder-type formulation of P. chlororaphis O6. Culturable bacteria in the formulated product were retained at above $1{\times}10^8$ colony forming units/g after storage of the powder at $25^{\circ}C$ for six months. Foliar application of the diluted formulated product controlled leaf blight and gray mold in tomato. The product also displayed preventative and curative controls for root-knot nematode (Meloidogyne spp.) in tomato. Under laboratory conditions and for commercially grown melon, the control was at levels comparable to that of a standard commercial chemical nematicide. The results indicated that the wettable powder formulation product of P. chlororaphis O6 can be used for control of plant microbial pathogens and root-knot nematodes.

• Journal of Applied Biological Chemistry
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• v.66
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• pp.388-393
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• 2023

This study evaluated the in vitro nematicidal activity of Glycyrrhiza uralensis root extracts (GuRE) on Meloidogyne incognita eggs and juveniles. The results showed that treatment of M. incognita eggs with 2.0 mg/mL GuRE for 5 and 10 d resulted in 64.0 and 68.1% hatch inhibition, respectively. Furthermore, the relative mortality of J2 was 96.2% after treatment with 2.0 mg/mL GuRE for 48 h. Changes in the shape of the eggs and juveniles were determined after incubation with 2.0 mg/mL GuRE for 5 d and 48 h, respectively. These preliminary results suggest that GuRE can be used as an environment-friendly bio-nematicide to control root-knot nematodes. In the future, in vivo assays should be conducted using GuRE to ascertain its potential for widespread application as a nematicide.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.2
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• pp.228-235
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• 2011

An nematophagous fungi Arthrobotrys thaumasia Nema-1 and Pseudomonas putida C-5, which degrade the collagen and gelatin, was isolated from controlled horticultural soils in Seonnam-myun, Sungju-gun, Kyungpook and Woosung-myun, Gongju-shi, Chungnam to develop biological nematode pesticide. When $5,000mL\;L^{-1}$ of A. thaumasia Nema-1 culture was treated to Meloidogyne incognita, the nematicidal activity resulted in 55% at 72 hours after treatment. While the nematicidal activity increased to 65% by treating the culture mixture of $5,000mL\;L^{-1}$ Nema-1 and P. putida C-5 after 72 hours. Furthermore, the nematicidal activity of the mixture containing cinnamon extract $50mg\;L^{-1}$, each $5,000mL\;L^{-1}$ of Nema-1 and C-5 culture was elevated to 89% at 72 hours after treatment, comparing to the result showed 17% and 57% of the nematicidal activity, respectively by the treatment of chemical nemato pesticide Fosthiazate $50mg\;L^{-1}$ and neem oil $2,000mL\;L^{-1}$. These results suggested that the mixture of microorganisms and plant extract were more effective biological nematicide than the case of only microorganism or plant extract for nematode control.

• The Plant Pathology Journal
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• v.34 no.1
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• pp.35-43
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• 2018

Root-knot nematodes (Meloidogyne spp.) are parasites that attack many field crops and orchard trees, and affect both the quantity and quality of the products. A root-colonizing bacterium, Pseudomonas chlororaphis O6, possesses beneficial traits including strong nematicidal activity. To determine the molecular mechanisms involved in the nematicidal activity of P. chlororaphis O6, we constructed two mutants; one lacking hydrogen cyanide production, and a second lacking an insecticidal toxin, FitD. Root drenching with wild-type P. chlororaphis O6 cells caused juvenile mortality in vitro and in planta. Efficacy was not altered in the fitD mutant compared to the wild-type but was reduced in both bioassays for the mutant lacking hydrogen cyanide production. The reduced number of galls on tomato plants caused by the wild-type strain was comparable to that of a standard chemical nematicide. These findings suggest that hydrogen cyanide-producing root colonizers, such as P. chlororaphis O6, could be formulated as "green" nematicides that are compatible with many crops and offer agricultural sustainability.

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.437-441
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• 2005

This study was investigated to compare the suppression of Meloidogyne arenaria by different treatments of Pasteuria penetrans which is known for biological control agent against Meloidogyne spp.. In order to select proper number of P. penetrans showing good suppression effect, P. penetrans were mixed with M, arenaria for attachment using three different concentration such as $3{\times}10^4$, $3{\times}10^5$ and $3{\times}10^6$ endospores/5 g medium, followed by treating them onto the roots of tomato. After 14 weeks incubation, P. penetrans at $3{\times}10^6$ endospores showed highest activity against the formation of gall caused by M, arenaria. At a dose of $3{\times}10^5$ endospores/5 g medium, P. penetrans was treated into soil either mixing with soil or spray onto soil surface for comparing of suppressive efficacy. When the antagonistic bacterium was treated by the former method, it suppressed more effectively Using P. penetrans at $3{\times}10^6$ endospores and mixing with soil method, suppression was compared among P. penetrans, $PASTORIA^{(R)}$(Japan) and $Fosthiazate^{(R)}$(Korea). P. penetrans was more potent than $PASTORIA^{(R)}$(Japan) and as similar as $Fosthiazate^{(R)}$(Korea). Therefore, these results suggested that P. penetrans can be used for controling of M. arenaria as biological control agent. Furthermore, thess results can be provided to develop environmentally-friendly nematicide.

• The Korean Journal of Pesticide Science
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• v.9 no.3
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• pp.268-273
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• 2005

The cultivating agroproducts are damaged by the Meloidogyne spp. which are gradually increasing in farm land soil. No effective control method for Meloidogyne spp., however, is available. Pasteuria penetrans which is one of the microorganisms in soil is used for biological control of Meloidogyne spp. although the method of mass production is limited. This study was conducted to investigate attachment and mass production effect of P. penetrans to M. arenaria under different temperatures (10, 30, 50 and $70^{\circ}C$) and pH values (4, 7 and 10). Attachment rates under these temperature and pH were more than 96% and 80%, respectively. In mass production rates, the number of P. penetrans attached on M. arenaria under different temperatures and pH were highly increased in root of tomato but not significantly different. Therefore, we concluded that P. penetrans can survive and attach on M. arenaria under various conditions. This method for mass production of P. penetrans can be provided to develop environmentally-friendly nematicide.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.2
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• pp.175-179
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• 2004

Trichoderma harzianum-THN1 parasitising the egg masses of root knot nematode Meloidogyne incognita was isolated from galled mulberry roots and evaluated for its potential to control root knot disease. In pot experiments root galling was reduced and leaf yield increased significantly following soil treatment with T. harzianum-THN1. The extracts obtained from the soils inoculated with T. harzianum-THN1 drastically inhibited the hatching of nematode eggs and the effect was irreversible even after the eggs were transferred to fresh water. The fungus was equally effective in controlling the disease in nematode infested mulberry garden under field conditions which was significant over the most commonly used egg parasitic fungus Paecilomyces lilacinus. The disease reduction recorded with T. harzianum was on par with the plants treated with the nematicide Carbofuran. The results suggest that T. harzianum- THN1 could be used as a potent ecofriendly biocontrol agent against M. incognita in mulberry without any residual toxicity to silkworms. T. harzianum- THN1 can form an important component of integrated disease management package in mulberry cultivation.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.353-357
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• 2004

Large economic losses have been reported by root-knot nematide, Meloidogyne incognita, in Korea. However, fewy environmentally-friendly nematicide alternatives for the control of M. incognita have been developed. This study was conducted of Korean native plants to screen nematicidal activity which could be used by organic farmers. Methanol extracts (1,000 mg $L^{-1}$) from fifty-three Korean native plants were applied to 24-well tissue culture testplates containing $1\times10^2$ M incognita and the nematicidal activities were determined. Nematicidal activities of the methanol extracts in common purslain (Portulaca oleraceae L.) and water mouse-ear-chickweed (Stellaria aquatica Scop.) were 60.0% and 40.6%, respectively, compared with that of control, however, those of other forty-one plants were less than 30%. Our results suggest that the methanol extracts of common purslain and water mouse-ear-chickweed contain nematicidal active compounds.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1150-1157
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• 2011

Streptomyces sampsonii KK1024 having strong chitinolytic activity was isolated from crab-shell rich soil at Muan, Jeolanamdo. The KK1024 produced chitinase, protease, gelatinase and lipase. When 50% of KK1024 culture broth was treated to juveniles and eggs of root-knot nematode, juvenile mortality at 3 days was 81.67% and egg hatch rate at 5 days was 2.00%. When $183.7{\mu}g\;mL^{-1}$ of crude enzyme produced by KK1024 was treated, juvenile mortality at 3 days was 96.00% and egg hatch rate at 5 days was 5.33%. At 1% of butanol extract from KK1024, juvenile mortality was highest with 90.00% and egg hatch rate was lowest with 0%. The comparison of the effect of KK1024 culture broth with only medium, synthetic fertilizer, and commercial nematicide on tomato growth and nematode infection was examined in pot trials. KK1024 culture broth showed lower number of egg mass and gall in plant, and population of juveniles in soil compared with only medium and synthetic fertilizer treatment, but not in commercial nematicide. However, the highest shoot weight and length was discovered in KK1024 culture broth. These results suggest that Streptomyces sampsonii KK1024 producing lytic enzymes and nematicidal compounds can be one of candidates for biocontrol agents against root-knot nematodes.