• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.351-372
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• 1998

The purpose of this study was to evaluate in vitro effects of the loss of tooth substance and root surface changes following root planing with various periodontal instruments. The 39 extracted human teeth due to severe periodontal disease were included. The total 50 root surfaces of 30 teeth were root planed with following instruments : Group 1, with Gracey curette, Group 2, with ultrasonic scaler, Group 3, with rotating root planing bur, Group 4, with Gracey curette plus rubber cup polishing, and Group 5, with ultrasonic scaler plus rubber cup polishing. Following root planing, the amount of tooth substance loss was evaluated by measuring the weight of the removed tooth substance and then 5 specimens ($5{\times}5{\times}2mm$) were randomly selected from the each group for roughness measurement. Root planed areas of each specimen were subjected to five measurements using the Profilometer and an average surface roughness values(Ra) for each group was obtained. Statistical difference for roughness values of each group was analyzed using oneway ANOVA and student t-test. For scanning electron microscopic(SEM) examination of root surface changes following root planing, 15 root surfaces of remaining 9 teeth were root planed and 3 specimens were randomly selected. The mean loss of tooth substance removed was Group 1, $7.0{\pm}1.09mg$, Group 2, $1.3{\pm}1.00mg$, Group 3, $5.8{\pm}1.72mg$, Group 4, $8.7{\pm}1.34mg$, and Group 5, $4.5{\pm}1.68mg$ following root palning, respectively. These results indicate that curette is effective instrument in the respect of diseased root substance removal. The average surface roughness values are following results : Group 1 and Group 4 were the smoothest surface ($Ra=0.34{\pm}0.06{\mu}m$, $Ra=0.34{\pm}0.04{\mu}m$, respectively) and Group 2 was the roughest surface ($Ra=2.09{\pm}0.06{\mu}m$). Statistical analysis of roughness values demonstrated a highly significant difference (P<0.05) between each experimental groups. However, no statistically significant difference in roughness values were observed between the Group 1 and Group 4. The results in this study suggest that curette and/or polishing procedure should be done after root planing with ultrasonic scaler and caution should be used with dia-mond-coated bur during routine root planing procedure.

• Journal of Periodontal and Implant Science
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• 제34권3호
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• pp.523-533
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• 2004

The purpose of this study was to evaluate the alveolar bone surface following root separation angle in the mandibular second molars. The fifty mandibular second molars(which were extracted) were selected, and the alveolar bone surface following root separation angle of the selected teeth were evaluated. The results were obtained as follows; 1. The root separation angle of fifty mandibular second molars were divided into three groups. The first $group(10-20^{\circ})$ was made up of ten teeth, the second $group(20-30^{\circ})$ was made up of fifteen teeth, and the third group(30-40$^{\circ}$) was made up of twenty-five teeth. 2. The mean root separation angle was $28.1^{\circ}$. The mean alveolar bone rate on the mesial surface of the mesial root was 44.27%, on the distal surface of the mesial root was 36.52%, on the mesial surface of the distal root was 33.45%, and on the distal surface of the distal root was 25.28%. 3. The mean alveolar bone rate on the distal surface of the mesial root, which composed the root separation area, was 32.95% in the first group, 36.06% in the second group, and 38.22% in the third group. The mean alveolar bone rate in the mesial surface of the distal root was 31.40% in the first group, 31.93% in the second group, and 35.18% in the third group. 4. The positive correlation was found between the root separation angle and the alveolar bone rate in the root separation area.(P<0.05) Although the mandibular second molar is a very important tooth in the oral cavity, its treatment and diagnosis is very difficult due to the variation of its root form. When periodontal disease involves the mandibular second molar, the result of this study assists in its treatment and diagnosis.

• 식물병과 농업
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• 제1권1호
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• pp.30-36
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• 1995

Infection rate of witches'-broom disease (WB) was observed yearly in transplanted jujube seedlings for 7 years. Seedlings of‘Hongan’grafted either on the rootstock from seed (RS) or on the rootstock from rooting (RR) were planted in separate farms. Occurrence of the disease was determined 4 years after transplanting with the witches'-broom symptom. Only 1 seedling of RS was infected with WB, while 56 seedlings of RR showed WB. Yearly infection rates of WB were observed in several varieties of jujube including‘Boeun’,‘Keumsung’,‘Moodeung’,‘Bokjo’,‘Koori’(10 trees for each in Cheongjoo), and‘Hongan’(165 trees in Boeun). In most varieties, WB first appeared in the third year from transplanting, and in the seventh year, more than 80% of the total tree showed WB. The yearly infection rate of newly infected trees was almost. stable during the first years. However, the ratio sharply increased from the sixth year. The accumulated infection rate of WB increased double, year by year from the third to seventh year. Between Cheongjoo and Boeun, no difference in infection rates was found.

• Applied Biological Chemistry
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• 제48권3호
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• pp.296-300
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• 2005

Among the root colonizing and plant growth promoting bacteria isolated from the bacterial wilt suppressive soil, five strains were detected to produce siderophores by CAS agar assay. The most effective isolate, TS3-7 strain induced significant suppression of bacterial wilt disease in tomato and pepper plants. Seed treatment followed by soil drench application with this strain resulted in over 80% reduction of bacterial wilt disease compared with the control. Significant disease suppression by TS3-7 strain was related to the production of siderophore. Besides iron competition, induction of resistance of the host plant with siderophore was suggested to be another mode of action that suppress bacterial wilt, based on the lack of direct antibiosis against pathogen in vitro. According to Bergey's Manual of Systemic Bacteriology and 16S rDNA sequence data, TS3-7 stain was identified as Pseudomonas sp. TS3-7.

• 한국식물병리학회지
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• 제14권6호
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• pp.729-731
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• 1998

A black leg disease in wasabi occurred, showed black spots on the leaves, changed a rhizome color to black by invading the vascular bundles of stem and root, thus lowered the quality of the rhizome. The mycelium of the pathogen was yellow at first and then turned to dark yellow on oat meal agar medium. The pycnidium was globose or subglobose, dark brown in color, and 44~120$\times$28~170 ${\mu}{\textrm}{m}$ in size and had one or two ostioles on the upper part. The pycnidiospores are single-celled, hyaline, and 4~6$\times$1.2~2.3 ${\mu}{\textrm}{m}$ in size. The causal pathogen was identified as Phoma wasabiae. The black leg disease of wasabi occurred within the range of 28 to 32% at Chonbuk province in 1994~1995. The disease was appeared from April to October and severe in June and July. The black leg caused by P. wasabiae was first described in Korea.

• 한국약용작물학회지
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• 제25권4호
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• pp.244-251
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• 2017

Background: The application of crop rotation systems may reduce the occurrence of soil-borne diseases by releasing allelochemicals and by subsequent microbial decomposition. Methods and Results: For reduction of ginseng root rot by the crop rotation system, after harvesting 6-year-old ginseng, fresh ginseng was grown along with continuous cultivation of sweet potato, peanut, and bellflower. Growth of 2-year-old ginseng was significantly inhibited in the continuous cultivation than in the first cultivation. Sweet potato, peanut and bellflower cultivations assisted in obtaining normal yields of ginseng in the first year after the harvest of 6-year-old ginseng. Salt concentration, potassium and sodium contents were gradually decreased, and, organic matter was gradually increased through cirp rotation. Phosphate, calcium and magnesium contents were not altered. The density of the root rot fungus was gradually decreased by the increase in crop rotation; however it was decreased distinctly in the first year compared to the second and third year. The severity of root rot disease tended to decrease gradually by the increase of crop rotation. Conclusions: Short-term crop rotation for three years promoted the growth of ginseng, however root rot infection was not inhibited significantly, although it was somewhat effective in lowering the density of the root rot pathogen.

• 한국자원식물학회지
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• 제12권4호
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• pp.260-268
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• 1999

황련(Coptis japonica)의 추출액을 공시하여 Phytophthora capsici, Fusarium oxysporum, Colletotrichum dematium, C. truncatum, Botrytis cinerea, Botryosphaeria dothidea과 Alternaria porri에 대해 항균 활성 검정, 몇가지 작물에 대한 병해 방제 효과를 조사하고 항균 활성 물질을 동정하였다. 황련 추출액은 P. capsici, F. oxysporum, C. dematium, B. cinerea, B. dothidea 및 A. porri에 대해서 항균력이 우수하였다. Methanol을 용매로 추출하여 분리된 물질과 berberine-Cl 표준품의 항균활성을 비교할 때, 황련추출액으로부터 분리된 물질은 표준품 berberine-Cl과 비슷하게 항균력을 나타내었다. 황련 추출액은 고추 역병(83.3%), 참깨 모잘록병 (92.0%) 및 파 검은무늬병(87.5%)에 대해서 방제효과가 인정되었다. 고추 잎과 과실, 파 잎 및 딸기 과실에는 약해가 나타나지 않았으나 고농도에서는 고추 및 참깨의 발아를 억제하거나 유근의 신장을 억제하는 것으로 나타났다. Methanol로 추출한 황련 추출액으로부터 황색 분말 4.24g/100g을 얻을 수 있었다. 이들 물질을 HPLC로 분석한 결과 항균성을 나타내는 물질은 berberine-Cl로 동정되었다.

• 원예과학기술지
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• 제34권2호
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• pp.242-248
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• 2016

This research was conducted to determine the effects of four different substrates, expanded rice hulls (ERH), commercial substrates for strawberries (CSS), clay sand (CS), and loamy sand (LS), on the inhibition of anthracnose crown rot (ACR) in strawberry. Mother plants of 'Seolhyang' strawberry were transplanted into an elevated bed in March, 2013 and March, 2014 and the runners connecting mother plants and daughter plants were cut in early August of both years. After separation, growth characteristics of the daughter plants were measured and then each daughter plant was inoculated with conidial suspensions of Colletotrichum fructicola, one of several species of Colletotrichum that causes ACR in strawberries. The incidence of ACR as influenced by the different substrates was investigated in both years. The daughter plants grown on CSS had the highest values for shoot height, leaf area, and fresh weight. Those grown on ERH and LS substrates also displayed good above-ground growth characteristics except for fresh weight, but the daughter plants grown on CS had the poorest above-ground growth characteristics. The ERH and CS treatments resulted in the highest number of primary roots and the greatest root weight. The CSS-grown daughter plants had the highest ACR disease index, followed by the CS and LS treatments, but there were no significant differences among the three substrates. However, the ERH-grown daughter plants had a markedly lower ACR disease index on October 11, 2013 and October 7, 2014. The CSS-grown daughter plants had high nitrogen and potassium contents and low calcium content, whereas the ERH-grown daughter plants had low nitrogen levels and high silicon levels. The results of this study provide basic information on the ability of the different substrates tested to provide disease suppression of ACR in the propagation of strawberry transplants.

• The Plant Pathology Journal
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• 제26권2호
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• pp.149-153
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• 2010

Biological and structural mechanisms of the nematode disease development in chili pepper caused by the root-knot nematode, Meloidogyne incognita, were investigated. Out of 39 chili pepper cultivars/lines tested, six were found resistant, while 33 were susceptible to M. incognita, of which a susceptible cultivar Chilseongcho and three resistant cultivar/lines CM334, 02G132 and 03G53 with different resistance degrees were selected for microscopic studies on the disease development. Gall formation was greatly reduced in the resistant cultivars/lines. Nematode penetration occurred both in the susceptible and resistant chili pepper roots; however, the penetration rates were significantly lowered in the three resistant peppers compared to the susceptible pepper cv. Chilseongcho. In the susceptible pepper, giant cells were extensively formed with no discernible necrosis around the nematode feeding sites. In the highly resistant pepper cultivar CM334, no giant cell was formed, but extensive necrosis formation was observed around the penetrating nematodes. In the other two resistant pepper lines (02G132 and 03G53), both giant cells and prominent necroses were formed, and the necrotic responses appeared to inhibit the further development of giant cells or accelerate their early degeneration. Although the nematode penetration was retarded significantly in the resistant cultivar/lines, all of the above results suggest that the disease resistance of pepper may be related to post-infectional defense mechanisms (nematode growth and development) more than pre-infectional ones (penetration and establishment). Variations in structural modifications in the resistant cultivar/lines may reflect their genetic differences related to the nematode resistance.

• 한국작물학회지
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• 제4권1호
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• pp.103-108
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• 1968

담배 각종병해저항성 품종육성의 기초자료를 얻기 위하여 우리나라 재래종에 대한 몇가지 병해에 대한 저항성검정을 하였다. (1) 역병에는 우방초, 오심엽초만이 중정도의 저항성이 있으며 수안초, 우설초, 광초 등이 그 다음이고 그 외품종은 모두 나병성이였다. DB 101, $H_2$, BY 4 등은 재래종보다 저항성이였다. (2) 흑근병에는 목기초, 우방초, 오심엽초가 중정도의 저항성이며 우설초, 수안초, 회초가 다음이며 향초는 BY 4만은 못하나 재래종중에서 가장 나병율이 높았다. (3) 야화병에는 대부분 나병율이 높은 편이나 흑초, 회초, 우방초가 약간 저항성이 인정되고 그 외품종은 거의 나병성이다. (4) 적성병에는 오심엽초가 고도의 저항을 엿보이며 우방초, 향초, 목기초 등이 중정도이고 광초, 우설초는 나병성이였다. 대조품종인 BY4나 Beinhart 1,000-1보다는 모두 나병율이 낮았다. (5) CMV-Y에 대하여서는 향초가 고도의 저항성이 인정되고 회초, 가자초가 저도이기는 하나 저항성이 있는 듯하다. (6) Blue mold병에 대에 하여는 공시품종 모두가 고도의 나병성임으로 이에 대한 저항성품종의 발굴이 절실히 요망된다.