• Korean Journal Plant Pathology
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• v.1 no.1
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• pp.22-27
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• 1985

Localized resistance against a virulent race of Erysiphe graminis f. sp. hordei by prior inoculation of a virulent or an avirulent race of the same fungus was induced on the near-isogenic barley leaves. Induced resistance could be detected within one hour following challenge inoculation with a virulent or an avirulent inducer race, hut the resistance increased greatly as the interval between the two inoculations was increased, showing the highest level by 6-9 hours of exposure to the inducer race. The level of the induced resistance was proportional to the amount of inducer inoculum applied. The resistances elicited by virulent or avirulent inducer races were similar with respect to the level of resistance and the time needed for its induction.

• Korean journal of applied entomology
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• v.30 no.1
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• pp.10-17
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• 1991

Cuticular penetration and detoxication as mechanisms of resistance to the carbamate insecticides in fenobucarb-selected($R_{f}$) and carbofuran-selected($R_{c}$) strains of the brown planthopper (N. lugens Stal) were investigated. Rates of penetration were not significantly different in the susceptible and resistant strains. However, total amount of excretion of the $R_{f}$ and $R_{c}$ strains were much larger than that of the susceptible strain. Fenovucarb and carbofuran were in vivo metabolizd much faster in the $R_{f}$ strain than in the susceptible strain. OSBP(o-sec-butyl phenol) and 3-ketocarbofuran phenol were invitro the major metabolites of fenobucarb and carbofuran in the brown planthopper, respectively. Total amount of the two major metabolites were produced abotu 2 times larger in the $R_{f}$ and $R_{c}$ strains compared to the susceptible strain. OSBP and 3-ketocarbofuran phenol were not so toxic to the brown planthopper ($LD_{50}$ >100 $\mu\textrm{g}$/g hopper). Based on our data, detoxication plays a large role in resistance to fenobucarb and carbofuran in the resistant strain of BPH, although several resistance factors maybe involved.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.68-74
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• 1998

벼멸구의 카보후란에 대한 저항성 기작을 구명하기 위해 실내에서 카보후란으로 30세대 도태하여 얻은 저항성계통($LD_{50};\;20.3{\mu}g/g$)과 약제를 12년 동안 처리하지 않은 벼멸구 감수성 계통($LD_{50};\;0.3{\mu}g/g$)을 완충용액과 마쇄하여, 105,000g에서 2시간 원심분리하여 얻은 상등액(에스테라제층)과 침전물(P450-산화효소층)을 효소액으로 하여 $^{14}C$-카보후란을 반응시켜 계통 간 대사물 량의 차이를 조사한 바 저해제(piperonyl butoxide; 산화효소저해제, diethylmalate; 글루타치온 전이효소 저해제, iprobenfos; 에스테라제 저해제)와 보조인자 (NADPH; P-450 산화효소, 글루타치온; 글루타치온전이효소)에 상관없이 카보후란의 대사물과 그 양이 계통간 차이가 없었다. 이상의 결과로부터 저항성 벼멸구에서 일반적으로 곤충에서 생화학적 저항성 기구로 잘 알려진 가수 분해 효소의 일종인 에스테라제와 p-450 산화효소, 글루타치온 전이효소의 활성 증가가 저항성 발달에 관여하지 않음을 알 수 있었다.

• Korean journal of applied entomology
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• v.37 no.2
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• pp.207-212
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• 1998

Tea field-collected populations of the tea red spider mite (Tetranychus kazawai Kishida) from five different locations in the southern region of Korea were assessed for resistance to seven acaricides using leaf spray method. There were considerable differences in susceptibility depending on the tested acaricides and the location from which the population was collected. The populations showing high resistance ratio of more than 20 with respect to certain acaricide were as follows: the Sungjun and Cheju populations to azocyclotin, tebufenpyrad, fenpyroximate, pyridaben, propargite, and fenpropathrin; the Haenam population to propargite and fenpyroximate; the Bosung population to propargite; the Youngam population to pyridaben. Therefore, the use of other alternative acaricides against the Sungjun and Cheju populations is needed. However, careful selection of the appropriate acaricide against the Haenam, Bosung and Youngam populations of the tea red spider mite might be maintained in effective control.

• The Korean Journal of Pesticide Science
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• v.7 no.4
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• pp.288-295
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• 2003

To determine the mechanism of the resistance to organophosphorus insecticide, chlorpyrifos, in diamondback-moth (Plutella xylostella L.), activities of esterases, glutathione-S-transferase (GST) and AChE insensitivity which were known for causing factor of resistance were measured. Also, the relationship between AChE insensitivity and the resistant ratio was investigated to inquiry the cross-resistance. The resistant ratio of chlorpyrifos-resistant strain (CRS) of diamondback-moth at the 6th generation was developed 160 fold compared to susceptible strain (SS) one. Activity of GST that are extracted from CRS was 1.7-fold higher than that from SS. However, activity of total esterases from CRS was similar to that from SS. In AChE insensitivity test, CRS was 11.8-fold less sensitive than that from SS. CRS was ranged from 17.6 to 33.6-fold less sensitive than SS to other insecticides having same target site with chlorpyrifos such as dichlorvos, dimethylvinphos and carbofuran. Insensitivity of AChE to phenthoate-oxon, however, was 1.7-fold. Resistance of CRS was 82-fold, 47-fold and 42-fold higher than SS to dichlorvos, dimethylvinphos and carbofuran, respectively, but 2.3-fold to phenthoate and then we could identify that the resistance development of insecticide might have a lot of difference among the chemicals with the same target site. The relationship between the AChE insensitivity and the resistant ratio was significantly correlated$(r=0.9951^{**},\;p^{(0.01)}$. This result indicates that AChE insensitivity was associated with insecticide resistance. Overall, these results suggest that insensitivity of AChE was an important factors to chlorpyrifos resistance in diamondback-moth, and the slightly increased activity of GST may also have contributed to that.

• Korean journal of applied entomology
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• v.32 no.3
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• pp.265-270
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• 1993

The German cockroach(Blattelia germanica) population~ were successIVely selected with ch\orpyrifos and permethrin during the six generations. The resulting resistant $R_{chtorpenfos}$(Rc) and $R_{permethnn}$(Rp) stra.ins were studied to investigate the esterase activity by spectrophotometer, filter parper test, and electrophoresis. Esterase-$\alpha$ activities by filter paper test showed 2.65 and LBZ times higher in the Rc and Rp strains than the susceptible strain, respectively. ln the spectrophoLometer method, the esterase activit18s to $\alpha$-and $\beta$-naphthyl acetate were increased 2.34 and 5.28 times in the Rc than susceptible strain, and 1.48 and 2.92 times in the Rp Limn susceptible stram, respectlvely. Zymogram patterns of eslerase isozyme by agarose gel electrophoresis showed totally five bands. The Rc and Rp strains showed two additive bands as, Est-2 and Est-3, which were not shown in the susceptible strain. but the Rp strain dId not show Est-5 bands which was COlumon in the Rc and susceptible strams.

• Research in Plant Disease
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• v.18 no.1
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• pp.35-39
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• 2012

Occurrence of tomato late blight (Phytophthora infestans) has caused significant losses in tomato yield in all over the world. Evaluation of the level of resistance in tomato gene resources for main breeding and initiation of the resistance breeding program are important for control of this disease. Resistant assay of 78 tomato cultivars/lines to late blight in pots and field experiment was carried out under controlled and natural conditions in 2009. All commercial cultivars including 'Legend' were susceptible. However, 10 lines including KNU-2, KNU-6-1, KNU-11, KNU-13, KNU-14-1 lines distributed from University of California, Riverside and L3708, $AV107-4{\times}L3708$, $07-15{\times}L3708$, $BS67{\times}L3708$ lines which have resistant gene Ph-3 and $06-9-62A{\times}06-9-62A$ were highly resistant to late blight. These highly resistant lines can be used as resources of resistance to late blight in a tomato breeding program in future.

• Korean journal of applied entomology
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• v.35 no.4
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• pp.297-301
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• 1996

This test has been carried out to evaluate the effect of temperature on the growth of the insecticide susceptible strain, URY-O nomal genotype and insecticide resistant strain, O-RT abnormal genotype, and ABURABI nomal genotype. The nymphal periods were not significantly different between URY-O and O-RY strains at $25^{\circ}C$. At $30^{\circ}C$, susceptible strain URY-O could give birth to offsprings almost nomally, while resistant strain O-RY could not produce any offspring for 20 days which results in nymphal death. The numbers of offsprings of strain URY-O and strain ABURABI were not different between $25^{\circ}C\;and\;28^{\circ}C$, but strain O-RY, when it was reared at $28^{\circ}C$, could produce offsprings only 10% of those at $25^{\circ}C$. Body weight of strain URY-O and strain ABURABI were 0.22mg/female and 0.27mg/female, respectively at $28^{\circ}C$, however that of O-RY was only 0.16mg/female, showing considerable difference between normal and abnormal genotype. Substrain O-RY(+) which has high esterase activity showed poor reproduction ability(0.8 progenies per $G_{1}$ individual than substrain O-RY(-) (3.4 progenies per $G_{1}$ individual) which has low esterase activity at $28^{\circ}C$

• Horticultural Science & Technology
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• v.31 no.6
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• pp.764-771
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• 2013

Recently, Cucumber mosaic virus (CMV)-P1 infection in pepper cultivation is very serious problem, which causes low marketability and yield. In this research, 56 domestic pepper cultivars including 20 PR (Phytophthora resistance) cultivars, 31 foreign pepper lines collected from USA and 112 genetic pepper resources form RDA Genebank were used for CMV-P1 resistance evaluation. Resistance evaluation was performed at 24 days and 51 days after artificial inoculation of peppers by enzyme-linked immunosorbent assay (ELISA). Among the 36 domestic cultivars 'Muhanjilju' were resistant to CMV-P1. All 20 PR cultivars and 29 foreign peppers except 'NuMex Twilight' and 'Chainese Giant' were susceptible. Among 112 pepper lines from RDA Genebank, nine pepper lines were resistant, and 17 pepper lines were moderately resistant, and 86 pepper lines were susceptible. Almost all domestic peppers on the market were highly susceptible to CMV-P1, whereas 17.2% of foreign pepper cultivars and genetic pepper lines from RDA Genebank were resistant or moderately resistant. Resistant pepper lines selected in this study can be used as genetic sources for breeding CMV-P1 resistant pepper.

• Korean journal of applied entomology
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• v.35 no.3
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• pp.260-265
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• 1996

A field colony of the two-spotted spider mite, Tetranychus urticae Koch, was selected with tetradifon for 4 mousing whole-plant residual method. This strain showed 371-fold resistance to tetradifon. The log dosehatchability lines of $F_{1}$ eggs(RS cross; Td5female$\times$Smale, and SR cross; Sfemale$\times$Td5male) were closer to the line of the resistant colony than to that of the susceptible. These differences could be due to cytoplasmic inheritance or maternal effect. The estimate of dominance index (D) for the $F_{1}$ eggs of RS cross was 0.998 and that for $F_{1}$ eggs of SR cross was 0.262. This indicates that tetradifon resistance is completely dominant in RS cross and incompletely dominant in SR cross. Td5 strain exhibited high levels of resistance to clofentezine, benzoximate, and chlorfencon, and no cross resistance to fenazaquin, pyridaben, flufenoxuron, tebufenpyrad, and fenothiocarb.