• Korean journal of applied entomology
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• v.41 no.3
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• pp.225-231
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• 2002

The entomopathogenic nematodes, Steinernema carpocapsae All strain (ScA), S.glaseri NC strain (SgN) and H. bacteriophora NC 1 strain (HbN), were evaluated for the effects on egg mass formation by the northern root-knot nematode, Meloidogyne hapla in pot experiment using tomato. In the first experiment, 2.5$\times$10$^{5}$ infective juveniles (Ijs) of entomopathogenic nematodes were inoculated to 100 g of the soil infected with ca. 450 Ijs of M. hapla/100 ㎤ in 150 $mell$ container. The number of egg mass was significantly decreased to 9.4-36.5 in ScA, to 5.7-24.7 in SgN and to 11.2-16.0 in HbN treatments compared with 62.5 in M.hapla alone. In the second experiment, ScA and S.carpocapsae Pocheon strain (ScP) and SgN and S.glaseri Dongrae strain (SgD) were treated to 350 g of the soil infected with 100, 200 M.hapla larvae/100 ㎤ in 450 $mell$ container The entomopathogenic nematodes were inoculated at the rate of 2,020 Ijs and 1.6$\times$105 Ijs in 350 g soil. The number of egg mass of M.hapla were significantly decreased in the entomopathogenic nematode treatments compared with M.hapla alone although no differences were observed among Steinernema species, strains, or infection concentrations. Treatments of entomopathogenic nematodes 3 days before M.hapla inoculation were more effective on reduction of egg mass formation than those of 3 days after M.hapla treatments. Growth of tomato was not affected by entomopathogenic nematode treatments.

• Development and Reproduction
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• v.6 no.1
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• pp.37-44
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• 2002

First sexual maturity, sex ratio, spawning frequency, deposition of the egg capsules and fecundity of the female Rapana venosa(Valenciennes) inhabited in the artificially closed slag deposit area, Gwangyang Bay were investigated by histologicai and visual observations for natural living resource management. The rate of individuals reaching the first sexual maturity was 51.6％ in females measuring 7.1~8.0 cm in shell height, and 100％ in those > 10.1 cm. The total number of egg capsules per individual and the mean number of eggs in an egg capsule were 192~382 and 500, respectively. However, the number of eggs per individual and sizes of egg capsules under lower salinity and deficient food conditions in the closed slag deposit area were smaller than those under the optimum salinity and sufficient food conditions in the open regions. Fecundities of the species were approximately from 96,000 to 191,000 eggs/individual with two to low broods(spawning frequencies) during the spawning season. The duration of development in egg capsules was 18~19 days at about 18~2$0^{\circ}C$. R. venosa is a species whose embryos hatch as veliger larvae, not juvenile snail. The sex ratio of female : male was not significantly different from 1 : 1($\chi$$^2$= 0.23, p>0.05).

• Research in Plant Disease
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• v.10 no.1
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• pp.25-29
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• 2004

Over 98％ of Dendranthema x grandiflorum plants growing under a glasshouse in Gumi, Korea were infested with Meloidogyne hapla. Dendranthema x grandiflorum cv, 'Ardilo' had fewer eggmass (3.3/g root), followed by cv. 'Euro' (6.5), and cv. 'Monarisa' had the most eggmasses(17). The coefficient correlation between plant growth and nematode reproduction(number of eggmass per plant) indicated that nematode reduced chlorophyll content in leaf (r = -0.418, p = 0.059; r = -0.463, p = 0.040). Number of flowers, number of leaves and stem height to flower were positively correlated with flower weight(p < 0.05).

• Proceedings of the Malacological Society of Korea Conference
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• 2002.11a
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• pp.6-6
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• 2002

• 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 Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.375-379
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• 2016

This study investigated the decomposing activities on gelatin and egg sac of root-knot nematode (Meloidogyne incognita). Ten Bacillus isolates (KRB-1~10) isolated from the soils of Mt. Naejang. Among them, KRB-5, 9, and 10 showed decomposing activities, and identified as Bacillus subtilis KRB-5, Bacillus amyloliquefaciens KRB-9, and KRB-10 by 16S rRNA sequence analysis, respectively. Under pot experiments using pepper, 100-fold diluted culture broth of three isolates reduced the number of egg sac on roots collected 60 days and 90 days and increased the growth of aerial part compared with the group only treated with Meloidogyne incognita. Especially, the group treated B. subtilis KRB-5 was superior in the growth of pepper. These results suggest that the B. subtilis KRB-5 can be used to control the root-knot nematode on pepper.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.119-206
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• 1998

Nematicidal potential of some plant extracts were evaluated for the control efficacy of the northern root-knot nematode, Meloidogyne hapla on tomato (Lycopersicon esculentum) in pot. Tagetes patula, Zoysia japonica, Rhus sylvestris, R. chinensis, and Allium cepu were used. Leaf or root extracts were prepared at the rate of undiluted and diluted to 2, 4, 8, or 16 times with distilled water and treated simultaneously, ahead or later tomato planting. Pre-treatments of extracts were more effective than simultaneous or post-treatments, and the number of egg masses was different according to concentrations. M. hapla was less infected when the T. patula was planted at 15 days ahead tomato planting. Leaf or root extracts of T. patulu reduced damages of M. hapla significantly in all treatments. Leaf extract was more effective than root extract; the number of egg masses was 2.2 and 5.5 in 5-days pre-treatment of leaf or root extracts while 129.4 in control. In Z. japonica treatment, the number of egg masses was 87.2 in control, 21 in undiluted concentration of leaf extract and 28.4 in diluted concentration as 2 times. Leaf extracts of R. sylvestris, R. chinensis and A. cepa were also very effective against M. Izapla. The number of egg masses of M. hapla was 1.6, 1.6, and 6.2 in 5-days pre-treatments of R. sylvestris, R. chinensis and A. cepa, respectively while it was 193.6 in control. Less egg masses of M. hapla were detected in higher concentrations than in lower concentrations of all the plant extracts.

• The Korean Journal of Malacology
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• v.21 no.2 s.34
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• pp.107-111
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• 2005

In the present study, the fecundation and fertilization behaviors of the trumpet shell, Charonia fampas sauliae were observed from November 2003 to March 2004. Female has multiple fecundation and multiple fertilization, and the fertilization continued for two days. The fertilized female stayed with the egg mass to protect the eggs, and the fecundation was made during the fertilization. The highest survival rate of egg capsule was 60% at $15^{\circ}C$. Charonia lampas sauliae fed with Chaetoceros calcitrans, Isochysis galbana, and Pavlova lutheri. Growth and survival rates of C. lampas sauliae in the conditions of various water temperature were observed. The highest survival rate was 23% at $15^{\circ}C$ reared for 60 days. The growth was presented in the $15^{\circ}C$ group, with shell length from $408{\pm}21.52{\mu}m\;to\;625{\pm}19.76{\mu}m$ during the experiment.

• The Korean Journal of Soil Zoology
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• v.6 no.1_2
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• pp.33-36
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• 2001

This study was carried out to screen 11 peony varieties collected for resistance to northern root-knot nematode, Meloidogyne hapla. The larval population of Meloidogyne halpa to the Uisongjakyak, Taebaekjakyak, Doseo, EP368, EP512 peony were detected high denisties with individuals of 98-173 per 300 ml soil, but Sabeol, Yongsu, Kimchon, Pl23 peony showed low number of larvar with 21-60. The root rot were lowered in Yongsu, Kimchon peony than Uisongjakyak, Taebaekjakyak, EP368, EP512. It seems to involved with densities of 2nd juvernile population in that rot rate of root was increased as increase of 2nd stage larvae. Two peony, Uisongjakyak, Taebaekjakyak were susceptable to M. hapla with high egg mass formation which showed 49,28 in each root. And Yongsu, Doseo, EP368, EP512 were Mid resistance with 1-15 egg mass of each root. Whereas Sabeol, Kimchon, Pl23, EP337, EP425 were found to be resistant to M, hapla with few egg mass formation of 4-7 each root.

• Horticultural Science & Technology
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• v.34 no.2
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• pp.282-293
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• 2016

Root-knot nematodes (Meloidogyne spp.) are major plant pathogens that cause reductions in yield and quality of several solanaceous crops, including pepper (Capsicum spp.). These losses can be averted through planting of resistant cultivars. Plants are defined as resistant when they suppress nematode reproduction. In this study, the resistance degrees of 102 commercial cultivars of chili pepper (Capsicum annuum) to a root-knot nematode, Meloidogyne incognita, were evaluated by comparing the number of egg masses on their roots to those of 'PR huimangchan', a highly susceptible cultivar that exhibited the most egg masses of the chili pepper cultivars evaluated. Among these cultivars, forty-four (43.1%) showed resistance to M. incognita and eighteen (17.6%) were moderately resistant. The other cultivars (39.3%) were determined to be susceptible. For further study, six chili pepper cultivars (i.e., Gangryeokjosenggeon, Shinsegae, Muhanjilju, PR Bulrocho, PR Huimangchan, and Jjang) with different levels of resistance to the nematode were selected. Changes in resistance of the six cultivars under several conditions, such as inoculum concentration, plant growth stage, and cultivation period after transplanting were investigated. We found that an efficient screening method for resistance of chili pepper to M. incognita is to transplant the chili pepper seedlings 7 days before inoculation, to inoculate 28-day-old plants with M. incognita by loading 5,000 eggs per plant into the pot of soil, to cultivate the plants in a greenhouse ($25{\pm}5^{\circ}C$) for 45-60 days, to measure the number of egg masses on roots of the seedlings, and then to determine the resistance response of the plants by comparing the number of egg masses on the roots with a reference-susceptible cultivar 'PR huimangchan'.