• 농업과학연구
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• 제50권4호
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• pp.829-840
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• 2023

Various chemical pesticides are used to control diamondback moths, Plutella xylostella, which are agricultural pests that occur in cruciferous crops worldwide and cause economic losses. However, due to pesticide misuse, resistance to P. xylostella is consistently reported domestically and internationally. Therefore, we aimed to monitor and map regional resistance to devise efficient and economical control methods for P. xylostella in Korea. This study selected eight highly used insecticides among those registered against P. xylostella. P. xylostella were collected from three cities in the Gyeonggi and Yeongnam Provinces to evaluate insecticide resistance. As a result of experiments with populations collected from Yeoju, Gyeonggi Province, resistance ratios were 114.88, 54.75, 119.00, and 64.00 times higher than the susceptible population with methoxyfenozide, indoxacarb, cyantraniliprole, and fluxametamide, respectively. The resistance ratios of the Yongin population in Gyeonggi Province were 166.33 times with cyantraniliprole and 195.25 times with fluxametamide higher than the susceptible population. The Pocheon population in Gyeonggi Province showed a resistance ratio 283.23 times higher than methoxyfenozide. As a result of experiments with populations collected from Gimhae and Sangju, Yeongnam Province, the resistance ratios of the Gimhae population were 80.97, 138.00, and 89.50 times higher than the susceptible population with methoxyfenozide, cyantraniliprole, and fluxametamide, respectively. Meanwhile, the resistance ratios of the Sangju population were 85.83, 224.67, and 303.25 times higher than the susceptible population with methoxyfenozide, cyantraniliprole, and fluxametamide, respectively. The Yeongnam Province Tongyeong population showed a resistance ratio 367.28 times higher to methoxyfenozide.

• 한국응용곤충학회지
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• 제48권3호
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• pp.301-310
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• 2009

Etofenprox에 대해 저항성과 감수성을 나타내는 복숭아혹진딧물의 개체군간의 살충율을 비교하기 위하여 추천농도(200ppm)로 처리한 결과, 24시간 후 저항성 개체군은 16.7%, 48시간 후는 36.7%의 살충활성을 보여주었고, 감수성 개체군은 24시간 후와 48시간 후에 86.7%로 두 개체군간 살충율은 큰 차이를 나타내었다. 또한 다른 합성 피레스로이드계 살충제의 교차저항성의 발달 여부를 알아보고자 6종의 살충제를 선발하여 추천농도로 살포하고 처리구당 10마리씩 10반복을 수행한 결과, 감수성 개체군과 저항성 개체군은 각각 deltamethrin에서 90%와 31%, lambda cyhalothrin에서 92%와 23%, cypermethrin에서 81%와 14%, $\alpha$-cypermethrin에서 70%와 20%, fenpropathrin에서 29%와 28%, fenvalerate에서 84%와 29%로 나타나 저항성 개체군이 전반적으로 피레스로이드계열 살충제에 대해 높은 저항성을 띄는 것으로 나타났다. 생태적 특성을 알아보기 위한 생명표 실험에서, 페트리디쉬와 포트 실험에서 감수성 개체군의 내적자연증가율($r_m$), 순증가율($R_0$), 평균세대기간($T_c$)이 두 그룹 간에 통계적으로 유의한 차이를 나타냈다. EPG를 이용한 두 개체군간의 약제처리 전후의 섭식행동에서 첫 potential drop이 나타난 시간은 살충제 처리 전 감수성 개체가 평균 73.5초로 저항성 개체의 257.9초 보다 더 빨랐고, 처리 후에도 93.3 초로 저항성의 1,076.2초 보다 빨랐다. 처리된 약제에 반응하여 섭식을 중단했다가 섭식을 재개하려는 전기적 접촉신호 빈도수에서는 감수성 개체는 8.2회, 저항성 개체는 48.8회로 저항성개체가 기주탐색 및 섭식을 재개하려는 시도가 더 많이 이루어진 것을 확인할 수 있었고, 처리 후에 총 섭식시간은 저항성 개체가 6,728.9초로 감수성 개체의 965.5초보다 섭식 시간이 훨씬 길었으며, 총 구침을 빼고 있는 시간도 처리 후 감수성 개체가 저항성 개체보다 3,000초 이상 긴 것으로 나타났다.

• 한국동물위생학회지
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• 제22권2호
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• pp.151-158
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• 1999

This study was conducted to investigate the biochemical characteristics, the population and antibiotic susceptibility test of Clostridium perfringens isolated from intestinal contents of slaughter cattle in Kyung-ju and Po-hang. 1. In slaughter cattle Cl perfringens were isolated from intestinal contents of 51 of 101 cases(50.4%) and the population were $\leq$$10^5$cfu/ml of 44 cases(86.3%). 2. In antibiotic susceptibility test, ampicillin, bacitracin, cephalothin, penicillin polymyxin B were highly susceptible, ohloramphenicol, erythromycin, tetracycline were lowly susceptible, gentamicin, kanamycin, amikacin, streptomycin, sulfamethoxine, sulfamethazine were resistant. 3. In leaving test intestinal contents leaved for 0, 4, 8, 16, 32 hours in room temperature and population of Cl perfringens were gradually increased.

• Fisheries and Aquatic Sciences
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• 제27권3호
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• pp.159-170
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• 2024

Research to obtain molecular markers related to the major histocompatibility complex (MHC) gene in both strains of gourami is essential to increase the success of the selection program of disease resistance traits. Using a completely randomized design (CRD), the challenge test consists of four treatments and seven replications. The treatment was Jambi gourami injected with PBS (KJ), Kalimantan gourami injected with PBS (KK), Jambi strain injected with Aeromonas hydrophila (GJ), and Kalimantan strain injected with A. hydrophila (GK). The GJ population was more resistant to A. hydrophila than the GK population. The MHC II gene was detected in both test strains (GJ and GK), both resistant and susceptible fish. However, there were differences in the results of amplifying the MHC II gene in susceptible and resistant fish. Two DNA fragments approximately 400 and 585 bp were detected in the genome of susceptible fish, while in the genome of susceptible fish, only one DNA fragment was detected (400 bp). Therefore, the MHC II gene fragment with a size of about 585 bp can be used as a potential candidate for specific molecular markers to obtain resistance to A. hydrophila bacteria in the giant gourami.

• 대한수의학회지
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• 제60권1호
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• pp.15-18
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• 2020

Canine heartworm disease is a vector-borne disease that is transmitted from dog to dog by mosquitoes. It causes epidemics that disrupt the health environments of dogs and are burdensome for many dog owners. Recent trends of changing temperatures and weather conditions in South Korea may have an impact on the population of mosquitoes, and it affects the population of dogs at risk of heartworm infection. Mathematical modeling has become an important measure for analyzing the epidemiological characteristics of infectious diseases. However, canine heartworm infection transmission has not been reported yet through mathematical modeling. We develop a mathematical model of canine heartworm infection to predict the population of infected dogs depending on the vector (mosquito) population using a susceptible, exposed, infected, and recovered model. Simulation results show that after 1 year, 3,289 dogs out of 73,602 (about 4.5%) are exposed and 134 (about 0.2%) are infected. Only 0.2% of susceptible dogs become infected after 1 year. However, if all exposed dogs are maintained in the same circumstances without any treatment, then the number of infected subjects will increase over time. This may increase the possibility of other dogs, especially dogs that live outside, being infected.

• 대한수학회지
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• 제54권3호
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• pp.987-997
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• 2017

A deterministic model for the spread of pine wilt disease with asymptomatic carrier trees in the host pine population is designed and rigorously analyzed. We have taken four different classes for the trees, namely susceptible, exposed, asymptomatic carrier and infected, and two different classes for the vector population, namely susceptible and infected. A complete global analysis of the model is given, which reveals that the global dynamics of the disease is completely determined by the associated basic reproduction number, denoted by $\mathcal{R}_0$. If $\mathcal{R}_0$ is less than one, the disease-free equilibrium is globally asymptotically stable, and in such a case, the endemic equilibrium does not exist. If $\mathcal{R}_0$ is greater than one, the disease persists and the unique endemic equilibrium is globally asymptotically stable.

• Journal of applied mathematics & informatics
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• 제40권3_4호
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• pp.393-407
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• 2022

In this paper, a diffusive predator-prey system with Beddington DeAngelis functional response and the modified Leslie-Gower type predator dynamics when a prey population is infected is considered. The predator is assumed to predate both the susceptible prey and infected prey following the Beddington-DeAngelis functional response and Holling type II functional response, respectively. The predator follows the modified Leslie-Gower predator dynamics. Both the prey, susceptible and infected, and predator are assumed to be distributed in-homogeneous in space. A reaction-diffusion equation with Neumann boundary conditions is considered to capture the dynamics of the prey and predator population. The global attractor and persistence properties of the system are studied. The priori estimates of the non-constant positive steady state of the system are obtained. The existence of non-constant positive steady state of the system is investigated by the use of Leray-Schauder Theorem. The existence of non-constant positive steady state of the system, with large diffusivity, guarantees for the occurrence of interesting Turing patterns.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.64.2-64
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• 2003

Twenty-seven monogenic rice lines harboring major resistant gene for blast were screened to analyze their resistance spectrum to Korean blast fungus population using 190 isolates collected from 1985 to 2002. Especially, the monogenic line containing Pi-9 gene was screened using 320 isolates. Based on the monogenic lines-blast isolate interactions, the 27 rice lines were classified into 9 groups. The chinese rice cultivar LTH showed susceptible to all the tested isolates. Those lines IRBLz-Fu, ERBL5-M and IRBL9-W harboring Pi-z, Pi-5, and Pi-9, respectively showed broader spectrum of resistance than those rice lines having Pi-19, Pi-7 etc. Interestingly, the Pi-9 gene(IRBL9-W) showed resistance to most isolates collected before 2000, but it showed susceptible reactions to 5％ and 20％ of blast fungus population in 2001 and 2002, respectively. Population of virulent isolates to Pi-ta, Pi-b, and Pi-7 also were increased in 2002 compared to those before 2000.

• Plant Resources
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• 제5권3호
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• pp.169-175
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• 2002

The soybean cyst nematode (Heterodera glycines Inchinoe; SCN) is a devastating pest of soybean and is responsible for significant losses in yield. The use of resistant cultivars is the effective method to reduce or eliminate SCN damage. The objective of this research is to identify AFLP markers linked to the SCN resistant genes. Bulked genomic DNA was made from resistant and susceptible genotypes to SCN and a total of 19 primer combinations were used. About 31 fragments were detected per primer combination. The banding patterns were readily distinguished in resistant and susceptible bulked genotypes. Polymorphic fragments were detected between resistant and susceptible bulked genotypes in the primer combination of CGT/GGC, CAG/GTG and CTC/GAG. In primer combinations of CGT/GGC and CAG/GTG, bulked resistant genotype produced a polymorphic bands. However, in primer of CTC/GAG, bulked susceptible genotype produced a polymorphic fragments. Three AFLP markers identified as a polymorphic fragments between bulked genomic DNA were mapped in 85 F2 population. Among them, only two markers, CGT/GGC and CTC/GAG, was linked and was mapped. Broad application of AFLP marker would be possible for improving resistant cultivars to SCN.

• Asian Pacific Journal of Cancer Prevention
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• 제13권10호
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• pp.5037-5042
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• 2012

Background: Tobacco contains agents which generate various potent DNA adducts that can cause gene mutations. Production of DNA adducts may be neutralized by glutathione S transferase (GST) along with other phase I and phase II enzyme systems. The existence of null type of GST among the population increases the susceptibility to various disorders and diseases. The present study focuses on the impact of high tobacco usage and possible null type mutation in GST loci. Methods: Genotypes of GST were detected by multiplex polymerase chain reaction in unrelated 504 volunteers of high tobacco using natives of Gujarat. Allelic frequencies were calculated using Statistical Package for Social Studies-16 software. Hardy Weinberg Equilibrium (HWE) was calculated using Chi square test. Two sided Fisher's significance test was used to compare allelic frequencies of different populations. Results: The frequency of homozygous null genotype of GSTM1 and GSTT1 were 20% (95% CI 16.7-23.9) and 35.5% (95% CI 31.4-39.9) respectively. The GSTM1 and GSTT1 null allele frequency distribution in the Gujarat population was significantly deviating from HWE. GSTT1 null frequency of Gujaratians was significantly higher and different to all reported low tobacco using Indian ethnics, while GSTM1 was not differing significantly. Conclusion: Tobacco usage significantly influences the rate of mutation and frequency of GSTT1 and M1 null types among the habituates. The rate of mutation in GSTT1 loci was an undeviating response to the dose of tobacco usage among the population. This mutational impact of tobacco on GSTT1 postulates the possible gene - environment interaction and selection of null genotype among the subjects to prone them under susceptible status for various cancers and even worst to cure the population with GSTT1 dependent drugs.