• Korean journal of applied entomology
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• v.43 no.1
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• pp.43-48
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• 2004

Development of 3,700 folds resistance to etoxazole was found in the population of twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Buyo, Chungnam Provience in August 2000. This population was selected for 3yr with etoxazole to get 5,000,000 folds increase in resistance as compared to susceptible (S) strain. The etoxazole resistance was stablized for 16 months under the condition of no acaricide application. Inheritance and cross resistance in etoxazole to some acaricides of the etoxazole resistance strain (R) were investigated. There were differences of susceptibility in the etoxazole concentration-mortality relationships between $F_1$, $F_2$ progenies obtained from reciprocal cross with the S and R strains (R$_{♂}$${\times}$S$_{♂}$${\times}$R$_{♂}$). Degrees of dominance were 0.98 and 0.98 in $F_1$ and $F_2$ progenies of R$_{♂}$${\times}$S$_{♂}$, and -0.97 and -0.68 in $F_1$ and $F_2$ progenies of S$_{♀}$${\times}$R$_{♂}$ respectively. Inheritance in $F_1$ and $F_2$ progenies of R$_{♀}$${\times}$S$_{♂}$ were complete dominant. However $F_1$ and $F_2$ progenies of S$_{♀}$${\times}$R$_{♂}$ were incomplete recessive. These results suggest that inheritance of etoxazole resistance is controlled by a complete dominance. The R strain exhibited cross resistance to acequinocyl and emamectin benzoates in adult females, and milbemectin, amitraz and pyridaben in eggs. However they showed negatively correlated cross-resistance to bifenazate, a carbazate acaricide. These results may indicate bifenazate could be useful for the control of etoxazole resistant T. urticae population.

• Current Research on Agriculture and Life Sciences
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• v.28
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• pp.39-46
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• 2010

Selection procedures for breeding lines resistant to both bacterial wilt caused by Ralstonia solanacearum and Phytophthora blight caused by P. capsici were executed to generations from $F_2$ and $BC_1F_1$ to $F_4$ and $BC_1F_3$ of crosses between a Phytophthora resistant breed, 'Chilbok No. 1' and bacterial wilt resistant accessions introduced from Vietnam during 2009 and 2010. The breeding populations or lines were tested for resistance to P. capsici and resistant plants were selected. The resistant selections were inoculated with R. solanacearum to discard susceptible plants. Resistance to P. capsici was conspicuously improved by selection from $F_2$ and $BC_1F_1$ and the final selections showed a similar level of resistance to P. capsici as a commercial Phytophthora resistant cultivar, Muhanjilju. A few $BC_1F_2$ selections were crossed to a cytoplasmic male sterile line, Chilbok-A, to identify their nuclear genotype interacting with male sterile cytoplasm. Majority of them was fixed to maintainer (Nrfrf) and only two resulted segregating into male sterile and male fertile plants indicating that the pollen parents were heterozygous in the fertility-restoring gene.

• Korean journal of applied entomology
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• v.30 no.2
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• pp.106-110
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• 1991

The mode of inheritance of resistance to fenvalerate in the diamondback moth (Plutella xylostella L.) was studied using insecticide susceptibility and mixed function oxidase tests. Tehre were no differences in the concentration-mortality relationships between $F_1$ progenies $(S_{female}\timesR_{male},\;R_{female}\timesS_{male})$ obtained from reciprocal crosses with the susceptible and fenvalerate-selected strains(R), indicating the absence of sex-linked inheritance. Degree of dominance of the $F_1$ progenies $(S_{female}\timesR_{male},\;R_{female}\timesS_{male})$ were -0.50 and -0.46, respectively, in the insecticide susceptibility test and -0.85 and -0.81, respectively, in the mixed function oxidase test. These results suggest that inheritance of fenvalerate resistance is controlled by and incompletely recessive autosomal gene.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.3
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• pp.342-348
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• 2013

It proposes an efficient control algorithm to increase electric power transmission efficiency between photovoltaic power generating system and the grid. The main controller finds a maximum efficiency condition by considering the quantity of power generated from PV arrays, the number of inverters, and efficiency of PV inverter. According to the condition, a relay board arranges a point of contract of PV arrays. By the disposition of PV arrays, it assigns the optimized power on each PV inverter. Operational principle of the proposed maximum efficiency point tracking algorithm is given in detail. To verify the validity of the proposed approach, computer-aided simulation and experiment carried out.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.54-61
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• 2012

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), is one of the most important pest species devastating many horticultural and ornamental crops and fruit trees. Difficulty in managing this mite is largely attributed to its ability to develop resistance to many important acaricides. Development of 3,700-folds resistance to etoxazole was found in the population of T. urticae collected from rose greenhouses in Buyeo, Chungnam Province in August 2000. This population has been selected for eleven years with etoxazole (over 500 times), and increased over 5,000,000-folds in resistance as compared with susceptible strain. Also, etoxazole-resistant strain was shown to be maternally inherited. The objective of this study was to determine whether resistance of T. urticae to etoxazole was linked with point mutations in the mitochondrial gene. DNA sequencing of cytochrome c oxidase subunit I (COX1), COX2, COX3, cytochrome b (CYTB), NADH dehydrogenase subunit 1 (ND1), ND2, ND3, ND4, ND5, and ND6 were analyzed by comparing two etoxazole-susceptible and etoxazole-resistant strains. As a result, differences were not detected between the nucleotide sequences of two strains within a mitochondrial gene.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.391-407
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• 1987

To understand the effects of the cooling water system of the power plant on the succession of sessile zoobenthos, a series of experiments were carried out at the cooling water system of Samchonpo Power Plant from Hay 1985 to May 1986. The lowest species diversity of the zoobenthos was observed at the discharge canal. This is probably caused by both increased velocity and temperature of circulating water. It is also noticeable that species composition of the zoobenthos, to a certain degree, was affected due to the impingement of meroplankton during the entrainment process. While the number of species attached on the experimental substrata installed in the thermally altered area is smaller than that in the intake canal, the biomass is increased as the increased temperature eliminates some species and in turn stimulates reproduction and growth of the others. It is interesting that relatively high similarity exists between the summer communities in the intake canal and the spring communities in the thermally altered area, and the same relationship is also found between the fall communities in the intake canal and the winter communities in the thermally altered area. Ecological index curves of the zoobenthos of the intake canal follows the fluctuation pattern of the thermally altered area in one or two months of elapsed time, probably due to temperature increase by the inflow of heated water discharged from the power plant.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.107-115
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• 2004

To develop universal primers for phylogenetic analysis and species-specific marker for breeding program of kiwifruit, eighteens primers were designed from kiwifruit genome-specific repeat sequences. Seven species including twenty two varieties collected from native eastern Asia were examined using 18 to 22 mer kiwifruit target(KT) primers. among eighteen primers, we selected seven primers for phylogenetic relationship. The genus Actinidia was divided into two large groups; group I,A. arguta, A. melanandra, A. kolomikta, and A. marcrosperma, characterized by the non-hair in fruits and loaves or a few pubescences only in young stage, which belongs to the section Leiocarpae, and group II, A. chinensis, A. deliciosa, and A. eriantha, characterized by a lot of hairs only in young fruit stage and with a lot of hairs or fuzzes in leaves and branches, which belongs to the section Stellatae. Group II especially belongs to the series Perfectae of the section Stellatae and was divided into two subgroups; subgroup I containing A. chinensis and A. deliciosa, and subgroup II containing A. eriantha. In contrast, the two species, A. chinensis and A. deliciosa, which are known to have common parents, were divided into two independent subgroups with 80％ of a similarity value. On the other hand, we selected KT6F for variety specific bands, KT12E primers for 'Hayward' and 'Tomuri'. KT7F or KT12F primers were useful for analysis of inheritance pattern in kiwifruit cross-breeding. We suggest that these primers will be a powerful tool for elucidating phylogenetic relationship and selection of novelty kiwifruit in a breeding program.

• Korean journal of applied entomology
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• v.44 no.2
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• pp.151-156
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• 2005

The development of resistance to bifenazate (resistance ratio of egg=40.3 folds) was found in population of the twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Chilgok, Gyeongbuk Province in December 2000. This population was selected for 4 years with bifenazate treatment (over 150 times), and showed 248.8 folds increase in resistance as compared to susceptible (S) strain. Inheritance of bifenazate resistant strain (R) and cross resistance of this strain to 9 acaricides were investigated. There were differences of susceptibility in the bifenazate concentration-mortality relationships in F1 progenies obtained from reciprocal cross with the S and R strain $(R{\times}S,\;S{\times}R)$. Degrees of dominance were 0.48 and 0.94 in adult females and eggs of $R{\times}S$ and -0.85 and -0.17 in adult females and eggs of $S{\times}R$, respectively. Inheritance type in the F1 progeny of $R{\times}S$ was incomplete dominant, and F1 progeny of $S{\times}R$ was incomplete recessive. These results suggest that inheritance of bifenazate resistance is controlled by a complete dominance. The R strain exhibited cross resistance to acequinocyl and fenpyroximate in adult females, and amitraz, emamectin benzoate, fenpyroximate, milbemectin, pyridaben and spirodiclofen in eggs. However they showed negatively correlated cross-resistance to emamectin benzoate and milbemectin in adult females, and abamectin in eggs.

• The Korean Journal of Pesticide Science
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• v.6 no.4
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• pp.264-270
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• 2002

Studies on the resistance monitoring of green peach ahpid, Myzus persicae, its development pattern by artificial selection with imidacloprid and cross-resistance were carried out to develope resistance management strategy. Resistance ratios of M. persicae collected at Hwachon and Dunnae among 5 locations in alpine cultivation area appeared to be high as 37.2 and 16.5, respectively. Resistance of aphid to imidacloprid developed slowly up to 20 time selection, and after that it grew quickly. Imidacloprid-resistant aphid strain showed low cross-resistance ratios(<10) to most of organophosphates, carbamates, and mixed insecticides except pirimicarb(487.8), but high ratios to acetamiprid(143.0) which is one of the neonicotinoids like imidacloprid, and pyrethroids such as deltamethrin(14.9), flucythrinate(12.9) and halothrin(15.9).

• The Korean Journal of Pesticide Science
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• v.11 no.2
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• pp.125-130
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• 2007

The development of resistance to acequinocyl was found in the population of the twospotted spider mite, Tetranychus urticae, collected from rose greenhouses in Gimhae, Gyeongnam province in January 2001. This pest is reared on 5 years treated with acequinocyl (over 200 times), and increased 87.8 folds in resistance as compared to susceptible strain (S). Inheritance of acequinocyl resistant strain (R) and cross resistance of this strain to 8 acaricides against T. urticae adults and eggs was investigated. There were differences of susceptibility in the acequinocyl concentration-mortality relationships in $F_1$ progenies obtained from reciprocal cross with the S and R strain ($S(female){\times}R(male)$, $R(female){\times}S(male)$). Degrees of dominance were -0.75, -0.57 in $F_1$ progenies of adult and egg of $S(female){\times}R(male)$. Inheritance in $F_1$ progenies of $S(female){\times}R(male)$ was incomplete recessive. Degree of dominance were 0.81, 0.45 in $F_1$ progenies of adult and egg of $R(female){\times}S(male)$, respectively. These results suggest that inheritance of acequinocyl resistance is controlled by a complete dominance. The R strain exhibited cross resistance of 1.1 and 0.9 fold to amitraz, bifenazate, and negatively correlated cross resistance of 0.08 fold to emamectin benzoate in adult females. The R strain showed cross resistance of 37.7, 14.0, and 26.2 fold to amitraz, milbemectin and spriodiclofen in eggs, respectively. Particularly it showed high levels of cross-resistance to pyridaben with 6538.3 fold. These chemicals showed negatively correlated cross-resistance exhibited 0.4, 0.3, and 0.2 fold to ahamectin, bifenazate, and emamectin benzoate in eggs.