• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.958-963
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• 2008

A series of experiments were conducted to assess the effectiveness of rhizobacteria containing 1-aminocyclopropane-1-carboxylate (ACC) deaminase for growth promotion of peas under drought conditions. Ten rhizobacteria isolated from the rhizosphere of different crops (peas, wheat, and maize) were screened for their growth promoting ability in peas under axenic condition. Three rhizobacterial isolates, Pseudomonas fluorescens biotype G (ACC-5), P. fluorescens (ACC-14), and P. putida biotype A (Q-7), were selected for pot trial on the basis of their source, ACC deaminase activity, root colonization, and growth promoting activity under axenic conditions. Inoculated and uninoculated (control) seeds of pea cultivar 2000 were sown in pots (4 seeds/pot) at different soil moisture levels (25, 50, 75, and 100% of field capacity). Results revealed that decreasing the soil moisture levels from 100 to 25% of field capacity significantly decreased the growth of peas. However, inoculation of peas with rhizobacteria containing ACC deaminase significantly decreased the "drought stress imposed effects" on growth of peas, although with variable efficacy at different moisture levels. At the lowest soil moisture level (25% field capacity), rhizobacterial isolate Pseudomonas fluorescens biotype G (ACC-5) was found to be more promising compared with the other isolates, as it caused maximum increases in fresh weight, dry weight, root length, shoot length, number of leaves per plant, and water use efficiency on fresh and dry weight basis (45, 150, 92, 45, 140, 46, and 147%, respectively) compared with respective uninoculated controls. It is highly likely that rhizobacteria containing ACC deaminase might have decreased the drought-stress induced ethylene in inoculated plants, which resulted in better growth of plants even at low moisture levels. Therefore, inoculation with rhizobacteria containing ACC deaminase could be helpful in eliminating the inhibitory effects of drought stress on the growth of peas.

• The Korean Journal of Pesticide Science
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• v.4 no.1
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• pp.51-58
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• 2000

These studies were carried out to investigate the toxicities of 43 registered insecticides to the sweetpotato whitefly(Bemisia tabaci, B. biotype). Insecticide activities were evaluated by testing systemic action and residual effect in the laboratory, and control efficacy in the greenhouse. All experiments were tested at the recommended concentration(ppm) of each insecticides. Insect growth regulators (IGRs), pyriproxyfen and teflubenzuron showed >95% ovicidal effect. The insecticides that showed >95% larvicidal activity on 3rd nymphal instars were abamectin, acetamiprid, imidacloprid, pyriproxyfen, and acetamiprid+ ethofenprox. Insecticides with >95% adulticidal activity were abamectin, acetamiprid, diazinon, endosulfan, fenitrothion, imidacloprid, methidathion, pirimiphos-methyl, pymetrozine, spinosad, acetamiprid+ ethofenprox, cartap kydrochloride+buprofezin, and fenpropathrin+fenitrothion. Abamectin, acetamiprid, imidacloprid, pyriproxyfen, and acetamiprid+ethofenprox showed both residual effect and systemic activity. In the control efficacy test on B. tabaci, 90% control values were obtained at 1st day after treatment of the insecticides including abamectin, acetamiprid, imidacloprid, pyriproxyfen and acetamiprid+ethofenprox but in pyriproxyfen, 90% control value was reached at 7th day after treatment. These results indicate that abamectin, acetamiprid, imidacloprid, pyriproxyfen and acetamiprid+ethofenprox can be used in control for B. tabaci in field.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.227-233
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• 1987

This study was conducted to determine the epidemiological characteristics of Campylobacter enteritis. A total of 187 fecal specimens of Korean native goat were examined for the presence of C. jejuni and C. coli by direct plating. Fifty strains isolated were examined for biochemical and serological properties and susceptibility to 19 chemotherapeutic agents. A total of 29(15.5%) C. jejuni and 21 (11.2%) C. coli were isolated from the fecal specimen of 187 Korean native goats. Of the 50 isolates of C. jejuni and C. coli, 29 isolates of C. jejuni grouped as 7 biotypes (1,2,3,4,6,7 and 8) and biotypes 1(34.5%), 2(17.2%) and 3(20.7%) were encountered most frequently. Twenty-one C. coli strains were differentated into biotype I (61.9% of the isolates) and biotype II (38.1%). Of the 29 C. jejuni strains examined, 24(83.0%) were typable by the Lior serotyping scheme and five isolates were non typable. C. jejuni grouped as 8 serotypes, serotype 4(24.1%) and 26(20.7%) were encountered most frequently. In the case of 21 strains of C. coli grouped as 6 serotypes, the most frequent serotypes were 21(28.6%) and 25(23.8%). Total of 50 strains of isolated were all susceptible to amikacin, clindamycin and tobramycine. Overall 85% of isolates were sensitive to erythromycin, doxycycline, chloramphenicol, flume-quine, kanamycin, gentamicin, nalidixic acid, polymyxin B, colistin, tetracycline and ampicillin, but about 65% of isolates were resistant to cefamandole and ethyl hydrocuprein hydrochloride.

• Korean Journal of Veterinary Research
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• v.27 no.2
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• pp.235-243
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• 1987

This paper deals with the distribution of Yersinia spp. isolated from the feces or the cecal contents of 1,755 pigs, 558 cows, 428 pigs slaughtered, 271 dogs slaughtered and 91 deer during the period of March 1985 to February 1986. Isolated Yersinia spp. were examined for serotype, biotype and antibiotic susceptibility of Y. enterocolitica. The results were as follows; One hundred and fourty-three stains of Yersinia spp. were isolated from 141(4.5%) out of 3,103 animals examined and their isolates were identified as Y. enterocolitica(138 strains), Y. kristensenii (3 strains), Y. intermedia(1 strain) and Y. pseudotuberculosis(1 strain). Yersinia spp. were isolated from 122(7.0%) of 1,755 pigs in piggeries, 15(3.5%) of 428 pigs slaughtered and 4(1.5%) of 271 dogs slaughtered, but no Yersinia spp. were isolated from cows and deer. The isolation rate of Yersinia spp. in pigs ranged from 5.9~8.0% in piggeries, it was higher in summer and autumn and highest in fattening pigs groups(10.4%), especially. One hundred and thirty-eight Y. enterocolitica isolates belonged to serotype 0 : 3(95 strains), 0 : 8(13 strains), 0 : 5(7 strains), 0 : 9(6 strains), 0 : 1, 2(1 strain) and untypable(16 strains), among them strains of serotype 0 : 3 biotype 3B(91 strains) were predominant. Antibiotic susceptibility test of 138 isolates of Yersinia spp. was performed by the agar dilution method, using 8 antibiotics as follows: ampicillin(Am), chloramphenicol, kanamycin, nalidixic acid(Na), rifampicin(Rf), streptomycin, sulfadimethoxine(Su) and tetracycline. All the strains tested were susceptible to Rf and Na, but resistant to Su, and 136 strains(98.6%) were also resistant to Am.

• Journal of Veterinary Clinics
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• v.40 no.4
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• pp.308-313
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• 2023

A 1-year-old castrated male Korean Shorthair cat presented with dyspnea, anorexia, lethargy, and seizures. Physical examination revealed salivation, right forelimb hemiparesis, and rapid breathing. No abnormalities were detected on auscultation. Laboratory findings revealed increased levels of bilirubin, aspartate aminotransferase (AST), globulin, glucose, and a decreased albumin-to-globulin (A:G) ratio. Both N-terminal pro-B-type natriuretic peptide (NT-proBNP) and feline serum amyloid A (fSAA) levels were significantly elevated. Thoracic radiography revealed mild cardiomegaly and diffuse increased interstitial infiltration with soft tissue opacity in the periphery of the right caudal pleural space. Echocardiography and lung ultrasonography were performed to investigate the cause of mild cardiomegaly and soft tissue opacity in the pleural space. Echocardiography revealed a mild amount of echogenic pericardial effusion, and lung ultrasonography showed an echogenic soft tissue mass with no blood signal in the right caudal pleural space, suggestive of a granulomatous lesion. After obtaining 5 mL of pericardial fluid through pericardiocentesis, cytology of the pericardial effusion sample revealed marked neutrophils and macrophages with no bacteria. IDEXX feline infectious peritonitis (FIP) virus real-time reverse transcriptase polymerase chain reaction (RT-PCR) confirmed the presence of the FIP virus biotype in the sample. This case presents a rarely reported atypical mixed form of FIP in a cat diagnosed ante-mortem using pericardial effusion analysis. In this case, ultrasound examination played a crucial role in the definitive diagnosis of FIP by PCR biotyping through pericardiocentesis. Ultrasonography can be highly beneficial in guiding the diagnosis and evaluation of cats with suspected FIP.

• The Korean Journal of Pesticide Science
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• v.7 no.3
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• pp.207-215
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• 2003

This study was carried out to evaluate toxicities of 3 registered insecticides to greenhouse whitefly(GWF), Trialeurodes vaporariorum and sweetpotato whitefly(SWF), Bemisia tabaci, B-biotype. Insecticide activities were evaluated by testing systemic action, residual effect in the laboratory, and control efficacy in the greenhouse. All experiments were tested at the recommended concentration(RC), half and a quarter concentrations of RC of each insecticides. Acetamiprid showed 45%, 42% ovicidal effect to greenhouse whitefly and sweetpotato whitefly at 40 ppm, respectively. Acetamiprid showed more than 97% larvicidal activities on the 3rd instars larvae of GWF and SWF at the recommended and its half concentrations. On the adults of the two whitefly species, acetamiprid and acetamiprid+ethofenprox showed more than 92% mortality even at half of recommended concentrations. Acetamiprid and acetamiprid+ethofenprox showed both residual effect and systemic activity. In the control efficacy test on GWF and SWF, 90% control values were obtained at the 3th day after treatments of acetamiprid and acetamiprid + ethofenprox by application with recommended concentration. These results indicate that acetamiprid and acetamiprid+ethofenprox can be used in the control of the two whitefly species in field.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.2
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• pp.152-159
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• 1990

Four active strains, producing siderophore and antagonizing to soil plant disease fungi, were isolated and identified from the wheat rhizosphere to reduce the injurious effects of continuous cropping and study on the biological control. The obtained results were summerized as follow. 1. Four strains of fluorescent Pseudomonas were isolated from the wheat rhizosphere and identified as Pseudomonas fluorescens Biotype A(Ps-1,2,5) and Biotype B(Ps-3) That strains inhibitied growth of R. solani, F.oxysperum and F. solani in vitro 2. Optical density of pigment was maximum at 410nm. 3. Siderophore production by identified strains was decreased with addition of $Fe^{+3}$, although not decreased with addition of $Fe^{+2}$ 4. Pigment of Ps-1, 2 and 3 strain inhibitied growth of R. slani, F. oxysperum and F. solani but pigment of Ps-5 strain did not inhibitie growth of R. solani 5. Effect of inoculation was in order of Ps-2, 1, 5 and 3 strain through the dark culture method, and effect of Ps-1 and Ps-2 was greater than that of treatment of captan 50ppm.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.4
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• pp.365-372
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• 2012

Native of soybean aphid (Aphis glycines Matsumura) is an Asia and aphid is one of the dangerous pests in soybean [Glycine max (L.) Merr.]. High density aphid populations can reduce crop production by causing severe damage. The objective of this study was evaluation of resistance to the soybean aphid in soybean cultivars and germplasms. A total of fifty five soybean cultivars or germplasms, including two susceptible and two resistant check varieties, were infested to evaluate their resistance in the field cage and greenhouse test by aphid colonies which derived from wild collected one soybean aphid biotype in Korea. The average number of reproduced soybean aphid was evaluated with 62.7 aphids in the resistant check variety PI 567598B and also estimated with 1,807 aphids for susceptible check variety Williams 82. In soybean varieties and germplasms, the average reproduced soybean aphid populations ranged from the lowest 497 aphids for Junjeori to the highest 3,862 aphids for Mansu. About seventy six percent of soybean cultivars and germplasms were shown high density soybean aphid populations when compared with another susceptible check variety PI 567543C in the field cage test. From the greenhouse test to evaluate aphid index, 87.3% of soybean cultivars or germplasms presented aphid index with 9.0. No soybean cultivars and germplasms were observed with soybean resistant phenotype when regarded a aphid resistant level as less than 10% aphid reproductions compared with susceptible check Williams 82. Although no Korean soybean cultivars were identified with resistant trait to the soybean aphid, we found one great resistant genetic resource PI 567598B in this study. This result will be helpful to further study for providing useful genetic information for soybean researchers.

• Korean journal of applied entomology
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• v.40 no.3
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• pp.203-209
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• 2001

Development and reproduction of the sweetpotato whitefly, Bemisia tabaci(B biotype) were investigated under different temperatures and host plants. Developmental periods from egg to pre-adult of whiteflies measured under four constant temperatures: they were 86.2 days at $15^{\circ}C$ and 17.0 days at $30^{\circ}C$. Lower threshold temperature and total effective temperature for the development of egg and nymph, and for the complete development (egg to emergence) were $10.1,\;11.6,\;11.1^{\circ}C$ and 110.3, 204.7, 317.3 degree days, respectively. The hatching and emergence rates were 87.0% at $25^{\circ}C$ and 76.7% at $20^{\circ}C$, which were higher than the results of other temperatures. The adult longevity was 23.6 and 14.0 days at $20^{\circ}C$ and $30^{\circ}C$, respectively. The highest average fecundity per female was 103.3 at $25^{\circ}C$. But there were no significant differences among the temperatures. The highest intrinsic rate of natural increase($r_{m}$) was 0.196 at $30^{\circ}C$ and the highest net reproduction rate ($R_{o}$) was 97.33 at $25^{\circ}C$. Developmental periods from egg to pre-adult of whiteflies were 21.2 on the tomato, 28.1 on red pepper, 22.2 on eggplant and 25.5 days on poinsetia. The hatching was highest (90.3%) on red paper and emergence rate was highest (89.6%) on eggplant. The longest longevity of adult female was 26.5 days on eggplant, and the average fecundity per female was greater on tomato and eggplant than on other host plants. The intrinsic rate of natural increase($r_{m}$) was the highest on tomato as 0.165 and the net reproduction rate ($R_{o}$) was the highest on eggplant as 106.1. As a result, the optimum range of temperature for the growth of B. tabaci was between $25^{\circ}C$ and $30^{\circ}C$, and the optimum host plant were tomato and eggplant among the plants tested.

• Korean Journal of Veterinary Research
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• v.28 no.1
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• pp.67-73
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• 1988

This study was conducted to isolate etiological agents from the 103 scouring piglets in Gyeongnam area and also carried out antimicrobial drug susceptibility test and epidemiogical served. The incidence of scouring piglet was most prevalent as 81.6% in the age of 2 to 4 weeks after birth, while the rate was less than 10% in the age of 5 to 6 weeks and under 1 week after birch. When compared the isolation frequency of the each etiological agent, enteropathogenic E. coli was most prevalent as 46.6%, thermophilic Campylobacter 26.2% and Salmonellae was 8.7% in order. In the OK serotyping for 117 isolates of enteropathogenic E. coli, type 0141 : K85 (20.5%), 0157:K88ac(14.5%), 0138:K81 and 0149:K91 (13.3%) were encountered most frequently. In the biotyping for 27 isolates of thermophilic Campylobacter, most strains of C. jejuni were belong to type I (50.0%) and II (25.0%), and most strains of C. coli were belong to biotype I (78.9%). In the serotyping for 9 strains of Salmonellae, 3 strains were grouped as D, 2 strains as C. and each 1 strain was group B and E. The other 2 strains were untypable. The 117 isolates of enteropathogenic E. coli were resistant more than 90% to erythromycin, penicillin, tetracycline and streptomycin, wherease about 90% of the isolates were sensitive to kanamycin and gentamicin. In the case of Salmonellae, all of the isolates were resistant to penicillin, but about 89% of the isolates were sensitive to gentamicin and colistin. All of C. jejuni and C. coli isolates were resistant to cephalothin, but more than 89% of C.jejuni and C. coli were sensitive to kanamycin and gentamicin.