• Journal of Applied Biological Chemistry
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• v.52 no.2
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• pp.51-57
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• 2009

To investigate expression patterns of chitinase, ${\beta}$-1,3-glucanase and peroxidase involved in biological control of phytopathogens, three oil seed rapes (Capitol, Pollen and Saturnin) were used. Activities of the enzymes in old leaves were $9.7{\sim}11.8$ unit/mg protein in chitinase, $11.1{\sim}17.3$ unit/mg protein in ${\beta}$-1,3-glucanase and $0.6{\sim}1.7$ unit/mg protein in peroxidase. Activities of the enzymes in roots were $39.2{\sim}49.0$ unit/mg protein in chitinase, $49.9{\sim}62.0$ unit/mg protein in ${\beta}$-1,3-glucanase and $2.4{\sim}3.8$ unit/mg protein in peroxidase. Chitinase and ${\beta}$-1,3-glucanase activity were the highest level in Saturnin leaves and in Capitol roots while activities of those were the lowest level in Capitol leaves. Also, chitinase and ${\beta}$-1,3-glucanase and peroxidase activity were the lowest level in Saturnin roots. Active bands of chitinase isoform in leaves (73, 51, 40, 34, and 29 kDa) and in roots (100, 57 34, and 29 kDa) tissues showed in the SDS-PAGE gel. Active bands of ${\beta}$-1,3-glucanase isoform in leaves and roots (75 and 55 kDa) tissues showed on the SDS-PAGE gel. Active staining of peroxidase showed the strongest level in leaves and roots of Pollen. Active bands of peroxidase isoform in leaves (122, 114, and 93 kDa) and in roots (135, 122, 114, and 93 kDa) tissues showed on the Native-PAGE gel. These results indicated that establishment of expression pattern of enzymes in rape tissues could play as an important role with respect to resistance of plant pathogens in rape.

• The Korean Journal of Pesticide Science
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• v.10 no.2
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• pp.76-83
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• 2006

In order to investigate the impacts of non-selective herbicide, glufosinate-ammonium (ammonium 4-[hydroxy(methyl)phosphinoyl] -DL-homoalaninate, GLA) to the non-target organisms, earthworm was exposed to GLA in the field soil for a month, and microbial populations in the soil were investigated after application of GLA. Simultaneously, the residues of GLA and its metabolite, 3-MPP were analyzed in the same soil. Meanwhile, to elucidate the influence of GLA to the growth of non-target crops incase of inter-furrow application, the amounts of carotenoid, chlorophyll, amino acid, proteins and sugars in the leaves of potato and chinese cabbage grown in the same field were investigated. In result, the dead earthworm was not observed during the test period, and the increasing rates of bodyweight were $9.410{\sim}11.603%$ in GLA-treated plots and 5.645% in GLA-untreated plots. The populations of fungi, bacteria and actinomycetes in the GLA-treated soils were $6.2{\times}10^4$, $1.5{\times}10^6$ and $5.7{\times}10^4$, respectively. They maintained relatively similar levels to the control which were $3.7{\times}10^4$, $3.7{\times}10^5$ and $3.7{\times}10^4$, respectively. In residue analysis, the limit of detection of GLA was 0.02 mg $kg^{-1}$, that of 3-MPP was the same level, and the half-life of GLA was 15 days in sandy clay loam soil. This result indicates that GLA was degraded very quickly in field soil. On the other hand, the amounts of physiological, biochemical components such as carotenoid, amino acid, chlorophyll, protein and sugar were ranged from 90.0 to 104.3% in potato and from 99.0 to 112.7% in chinese cabbage. Comparing with hand-weeded plots, it is indicated that GLA had not affected to the growth of non-target crops when applied at inter-furrow in crops-growing field.

• Korean journal of applied entomology
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• v.58 no.4
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• pp.321-327
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• 2019

When Aphidius colemani mummies were stored at four different temperatures (6, 8, 10 and 12 ± 1℃), they could be stored at 8℃ for 10 days with over 50% adult emergence. A number of mummies of Rhopalosiphum padi parasitized by A. colemani adults emerged from mummies after 8℃ storage clearly reduced with increasing duration of storage and especially declined with storage longer than 13 days showing < 20% parasitism. However, there were no differences in aphid parasitisms by A. colemani on 3 to 10 days after storage. Over 3 day storage at 8℃ was adversely affected on survival of A. colemani adults. Therefore, cold storage of A. colemani adults is considered as an unsuitable method for mass production of biological control agent. When 2-day-old Meteorus pulchricornis cocoons were stored at 6, 8 and 10 ± 1℃, it was possible to be stored up to 63 days at 8℃, showing the highest emergence. With increasing of cold storage duration at 8℃, parasitism on 2^nd and 3^rd larval instar of Spodoptera litura by stored M. pulchricornis significantly reduced. However, parasitic rate by M. pulchricornis stored for 2 weeks was similar to that by 1 week stored ones. Therefore, M. pulchricornis cocoons could be stored up to 2 weeks at 8℃ for stockpiling before release.

• Journal of agricultural medicine and community health
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• v.25 no.2
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• pp.245-263
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• 2000

This study was conducted to provide the basic data about the health effects of pesticide exposure among farmers for agricultural health study. We analyzed 412 self-administered questionnaires collected from the male farmers who spray pesticides in Kyoung-ju area, Korea. Survey questions were about chronic symptoms, acute symptoms while pesticide spraying, pesticide intoxication accident, safety rules, protective equipments etc. The correlations among the variables related to pesticide exposure and the factors in acute pesticide poisoning and chronic symptoms of farmers were also analyzed. For chronic symptoms, the prevalence of 'tiredness and languor', 'lumbago', 'nocturia', 'shoulder pain', 'numbness', and, for acute symptoms while pesticide spraying, the experience rate of 'itching sense of skin', 'dizziness/headache', 'fatigue', 'eye glaring' were high compared with other symptoms. For 'experience of intoxication accident by pesticide in family', 7.1% of the subjects experienced the accident and the causes were pesticide spraying, food contamination by pesticide, suicide etc. Among safety rules, 'take a bath after spraying', 'change clothes after spraying' were kept relatively well, and, for protective equipments, hat, boots, mask, gloves, protective clothes(lower) were put on relatively well. The factors associated with acute pesticide poisoning were the extent of keeping safety rules, spraying time, orchard cultivation, agricultural area and spraying days per year etc. And the factors associated with chronic symptoms were acute symptoms while pesticide spraying, agricultural area, farming career, extent of keeping safety rules, extent of agricultural work and the pesticide exposure index etc. From these results, it is suggested that to reduce the health effects by pesticide exposure among farmers, the education to promote to keep safety rules and wear protective equipments, and information services should be recommended. And further studies on the long term health effects of pesticide exposure among farmers are required.

• Korean journal of applied entomology
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• v.53 no.4
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• pp.427-433
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• 2014

To investigate the biological control of Aulacorthum solani, a comparative analysis was carried out using an indigenous natural enemy, Ephedrus plagiator, and an exotic parasitoid, Aphidius ervi. Lifespan, spawning periods, number of mummies, number of offspring, and developmental periods of the two parasitoids on Aulacorthum solani and Acyrthosiphon pisum were studied at 15, 20, 25, and $30^{\circ}C$ with a photoperiod 16 h (L): 8 h (D). The lifespan of E. plagiator (5.3 days) was relatively higher than that of A. ervi (2.3 days) when these parasitoids were reared on A. solani at $15^{\circ}C$. Similarly, the spawning period of E. plagiator (5.3 days) was longer than that of A. ervi (2.2 days). When the two aphid parasitoids were provisioned with A. solani, the numbers of E. plagiator mummies at 15, 20, 25, and $30^{\circ}C$ were 71.5, 41, 15.7, and 7.7, respectively, whereas at the same temperatures, the numbers of A. ervi mummies were 22.1 16.3, 6.2, and 0.4, respectively. In contrast, when provision with A. pisum, the numbers of E. plagiator mummies at 15, 20, 25, and $30^{\circ}C$ were 70.3, 69.8, 34.3, and 8.4, whereas the numbers of A. ervi mummies were 93.4, 71.2, 34.8, and 14.5, respectively. The numbers of E. plagiator offspring emerging at 15, 20, 25, and $30^{\circ}C$ were 42.1, 36, 11.6, and 0, whereas the numbers of A. ervi offspring emerging were relatively lower at 19.6, 13.5, 3.7, and 0.1, respectively. By comparing these results, it can be concluded that E. plagiator is a more efficient parasitoid of A. solani, whereas A. ervi is more efficient on A. pisum.

• The Korean Journal of Mycology
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• v.36 no.2
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• pp.153-162
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• 2008

Pinewood nematode (PWN) trapping by nematophagous fungi, Arthrobotrys conoides, A. dactyloides and A. oligospora and the fungal growth were characterized. The three Arthrobotrys species each was inoculated into the PWN cultured on Botrytis cinera fungal colony on potato dextrose agar (PDA). The effects of temperature, pH, PWN inoculation density and nutrients on the growth of the three Arthrobotrys spp were measured. A. conoides grew fast, 13.9 mm/day while A. dactyloides grew slow, 3 mm/day. PDA medium was the best for the fungal growth at $25^{\circ}C$ and pH 4.5. The Arthrobotrys spp growth was stimulated by 500 nematodes inoculation but not by 1000 inoculation. A. dactyloides did not grow below pH 4.5 and at high PWN density. A. conoides and A oligospora formed trapping organs with thick constricting hyphal network only when PWN present, while A. dactyloides formed the organ with circular hyphae constitutively. A. conoides formed trapping organs faster than A. oligospora did. The nematode trapping hyphae of the fungi penetrated into PNW inside to form many tiny infection bulbs and to digest the nematode. However, A. dactyloides formed a few trapping organs but no trapping was observed. Infection rate of PWN was 95% by A. conoides, 80% by A. oligospora and 92% by the combination inoculation of A. conoides and A. oligospora. In contrast A. dactyloides increased PWN density without infecton. There was no interaction effect in any combination inoculation of the three Arthrobotrys spp. A. conoides enhanced PWN infection rate by rapid hyphal growth and early trapping, while A. oligospora did it by increasing hyphal density. In conclusion A. conoides is the most effective in both hyphal growth and infection, and thus these characteristics can be utilized as a biological control of PWN.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.269-277
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• 2011

Recent outbreak of new diseases and pests which were introduced from abroad, seriously hampered both quality and safety of paprika fruits. This study has been carried out to aid an establishment of guideline for safe use of pesticides and reduction of their residues on paprika. Systemic fungicides boscalid and pyraclostrobin of either mixed (a.i.; 13.6+6.8%) or single (a.i.; 47 and 18.8%, respectively) water dispersible granule formulation(WG) products were sprayed with recommended or double dosage on paprika grown in green house at March and June. To draw pre-harvest residue limit, residues of each fungicide were analyzed from fruits collected eight times from 18 to 1 day pre-harvest. The biological half-lives of both boscalid and pyraclostrobin in mixed formulation in March and June were slightly shorter than those of single formulation which ranged from 14.4 to 20.1 days. Residue levels of both fungicides of single formulation in fruits in June were about one lower compared to those in March. However, application of double dosage frequently exceeded MRLs from fruits grown both seasons. These results showed that residue levels on fruits persisted longer period of time, more than two weeks, and so the case applied in winter season. The dissipation of fungicides on leaves and fruits was compared. The distribution of both fungicides in leaves was 20-200 times higher than that of fruits and persisted up to 18 days of pre-harvest period at the concentration of 10-40 ${\mu}g\;g^{-1}$. This study indicated that the mixed formulation product exhibited low residues in fruits, but high and long enough to pathogen growth in leaves.

• The Korean Journal of Pesticide Science
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• v.10 no.4
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• pp.344-350
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• 2006

An Antiviral producing bacterial strain was isolated from ginseng root environment in Hongcheon, Kangwon province of Republic of Korea. Identification of this bacterial strain was performed by physiological and biochemical tests along with 16S rRNA analyses. The results revealed that the bacterium was closer to genus Serratia, which was named as Gsm01. The strain was grown in Mannitol-Glutamate-Yeast (MGY) broth for 48 h. The culture was centrifuged and the filtrate obtained was tested for its ability to control Cucumber mosaic virus strain Y (CMV-Y) in greenhouse and field experiments. In the green house experiments, CF was evaluated for its ability to protect local host, Chenopodium amaranticolor and systemic host of CMV, Nicotiana tabacum cv. Xanthi-nc. It was found that, CF treatment reduced viral infection by 98% in local host; C. amaranticolor. The N. tabacum cv. Xanthi-nc plants treated with CF did not show visible viral symptoms 15 days post inoculation (dpi) and remained symptomless throughout the periods of the study. To evaluate effectiveness of CF under field conditions, experiment was carried out in a polyvinyl house. It was observed that, 52% plants were protected from viral diseases compared to non-treated plants, increasing the crop yield. This is the first report showing antiviral activity of a Serratia spp. against CMV.