새로운 침투성 살균제 EL-291 (5-Methyl-1,2,4-tri-azolo(3, 4-b) benzothiazole, 수화제)의 벼 도열병 방제효과를 구명코저 온실검정과 포장시험을 실시하였다. EL-291은 병원균 접종후 살포보다 접종전 살포시 효과가 뚜렷하여 현저한 예방효과를 나타냈으나 가스가민, 벤레이트 상반된 반응을 나타내어 치료제로서 작용했다. 잎 도열병방제효과는 EL-291과 가스가민, 벤레이트간에 차이가 없었으나 이들 약제의 2회 살포에 비해 EL-291은 근침처리 또는 1회 살포한 것이므로 사용이 간편하고 경제적이라 할 수 있겠다. 이삭도열병에서도 1회 살포한 EL-291이 2회 살포한 가스가민, 벤레이트보다 월등히 효과가 좋았으며 수량도 EL-291 처리구가 더 많았다.

Background : This study was conducted to investigate the resistance of Collectotrichum gloeosporioides to 9 fungicides. Methods and Results : With 3 isolates of Collectotrichum gloeosporioides obtained from diseased leaf of ginseng, it was conducted to detect the fungicide resistance of C. gloeosporioides against 9 chemicals through an agar dilution method. PDA medium was used for monitoring the resistance. Among the chemicals, fenhexamid・prochloraz manganese complex, fluazinam and metconazole exhibited high antifungal activity to the ginseng anthracnose fungus. When measuring the effectiveness for the prevention of anthracnose, 3 fungicides at 10 ㎍/㎖ showed 88.1 - 94.7% of preventive effect against C. gloeosporioides. But, the isolates resist to dimethomorph・dithianon, iminoctadine tris (albesilate), kasugamyci n・thiophanate-methyl, dimethomorph・pyraclostrobin, azoxystrobin. Conclusion : In summary, to develop the control system with fungicides, 3 fungicides (fenhexamid・prochloraz manganese complex, fluazinam and metconazole) were applied on ginseng at the indicated time. A reduced spray program based on efficacious fungicides will be useful for ginseng growers and provide more options for controlling anthracnose in Korea.

Background : Among registered fungicides for controlling ginseng disease, the disease occurrence rate from the mixed use of a single ingredient, mancozeb WP, and copper sulfate basic WP was examined, and experiments were conducted to establish safe disease control system. Methods and Results : As for the medicines used for the experiments, besides registered Pyraclostrobin WG as a single ingredient for ginseng disease control, 14 kinds were used for experiments. The fungicide was sprayed 5 times on June 21, July 4, July 16, August 2 and August 24. The examination was conducted 5 days, 10 days, 15 days, and 20 days after the final fungicide treatment. Anthracnose occurrence rate 5 days after the final fungicide treatment was 0.0 - 61.3% which was different depending on fungicides, and in a single treatment, the occurrence rate was less than 1% in 6 fungicides. In the single treatment, the occurrence rate was more than 1%, but 9 kinds of fungicides which had less than 1% occurrence rate in the case of mixed use with mancozeb, and one kind in the case of mixed use with copper sulfate basic 10 days later, the occurrence rate was 0.0 - 100% and there were lots of differences in the disease occurrence rate depending on fungicides. 10 kinds of fungicides showed the disease occurrence rate of more than 10.0% in the case of a single treatment. Among them, 9 fungicides showed the disease occurrence rate of less than 1.0% in the case of mixed use with mancozeb, indicating the effect of lowering disease occurrence rate in the case of mixed use. 15 days later, 9 fungicides showed disease occurrence rate of more than 2%, 1 kind of fungicide had the disease occurrence rate of less than 1%, and the overall disease occurrence rate increased. Among them, 7 kinds of fungicides showed the disease occurrence rate of less than 1% from the mixed use. 20 days later, 12 kinds of fungicides showed the disease occurrence rate of more than 50%, and only 1 kind of fungicide showed the disease occurrence rate of less than 1%. In the case of mixed use with mancozeb, 2 kinds had the disease occurrence rate of less than 10% and 1 kind of fungicide had the disease occurrence rate of less than 1%. Conclusion : For prevention of anthracnose disease of ginsengs during a rainy season, the disease occurrence rate from a single or mixed use was examined, and the examination found that rather than a single use, mixed use decreased the disease occurrence rate. In particular, the mixed use with mancozeb showed low disease occurrence rate and prevented the disease occurrence rate for a long time.

We investigated the toxic effects of difenoconazole on the development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of difenoconazole (0-30 μM). LC100 for difenoconazole was 30 μM, and the LC50 determined by probit analysis was 27.19 μM. Exposure to difenoconazole concentrations ≥5 μM resulted in 10 different types of severe external malformation. Histological examinations revealed dysplasia of the eye, heart, liver, somatic muscle, and swelling of the pronephric ducts. The tissue-specific toxic effects were investigated with an animal cap assay. Blood cells were normally induced at a high frequency by mSCF and activin A. However, the induction of blood cells was strongly inhibited by the addition of difenoconazole. Electron micrographs of tested embryos showed the degeneration of somatic muscle and the shrinkage of microvilli on pronephric duct. The gene expression of cultivated animal cap explants was investigated by reverse transcriptase-polymerase chain reaction (RT-PCR). It revealed that the expression of the blood-specific marker(β -globin Ⅱ) and muscle-specific marker (XMA) were more strongly inhibited than the neural-specific marker(XEn2) by the addition of difenoconazole.

We investigated the toxic effects of tebuconazole on development in the African clawed frog, Xenopus laevis. To test the toxic effects, frog embryo teratogenesis assays using Xenopus were performed. Embryos were exposed to various concentrations of tebuconazole(0-100 μM). LC100 for tebuconazole was 100 μM, and the LC50 determined by probit analysis was 82.35 μM. The exposure to tebuconazole concentrations ≥40 μM resulted in 11 different types of severe external malformations including gut dysplasia. Histological examinations revealed various dysplasia in the eye, heart, liver, intestine, somatic muscle, and in the pronephric ducts. The tissue-specific toxic effects were investigated with an animal cap assay. Blood cells are generally induced at a high frequency by the combination of mSCF and activin A, however, the induction of blood cells was strongly inhibited by the addition of tebuconazole. Electron micrographs of tested embryos showed many of multivesicular bodies and dysplasia of photo-receptive cell, however, the somatic muscle degeneration was not severe. The gene expression of cultivated animal cap explants was investigated by reverse transcriptase-polymerase chain reaction and revealed that expression of the blood-specific marker, β globin Ⅱ and muscle-specific marker, muscle actin were more strongly inhibited than the neural-specific marker, XEn2.

하대두는 추대두에 비하여 생육특성상 고온다습의 조건에서 성숙하는 관계로 미이라병의 종자감염이 높아 적정입모를 확보하기 위해서는 종자소독의 필요성이 요구된다. 따라서 본 시험은 입중을 달리한 하대두 계통에서 종자소독에 의한 입모율 향상이 후기생육 및 수양에 미치는 영향과 미이라병의 감염정도에 따른 종자소독제의 처리효과를 구명코자 하였다. 1. 입중을 달리한 하대두 계통에 종자소독제를 분의 처리하여 파종하면 무처리에 비하여 발아율이 향상되었고 배축장이 길었으며 약제처리의 약효는 대립종에서 높고 소립종에에서 낮은 경향이였다. 2. 종자소독제를 처리했을때 후기생육, 주당엽수, 백립중 및 수양은 무처리와 비교하여 큰 차이가 없었다. 3. 동일품종내에서 미이라병의 가시적 감염증세가 경미하면 종자소독제의 처리효과는 적었고 심할수록 약제처리에 의하여 발아율과 발아세가 현저히 향상되었는데 그 정도는 대립종에서 높았다.