• 한국균학회소식:학술대회논문집
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• 한국균학회 2016년도 춘계학술대회 및 임시총회
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• pp.25-25
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• 2016

Biological control has many advantages as a disease control method, particularly when compared with pesticides. One of the most important benefits is that biological control is an environmental friendly method and does not introduce pollutants into the environment. Another great advantage of this method is its selectivity. Selectivity is the important factor regarding the balance of agricultural ecosystems because a great damage to non target species can lead to the restriction of natural enemies' populations. The objective of this research was to evaluate the effects of several different bacterial isolates on the efficacy of biological control of soil borne diseases. White rot caused by Sclerotium cepivorum was reported to be severe disease of garlic and chive. The antifungal bacteria Burkholderia pyrrocinia CAB08106-4 was tested in field bioassays for its ability to suppress white rot disease. In field tests, B. pyrrocinia CAB08106-4 isolates suppressed white rot in garlic and chive, with the average control efficacies of 69.6% and 58.9%, respectively. In addition, when a culture filtrate of B. pyrrocinia CAB08106-4 was sprayed onto wounded garlic bulbs after inoculation with a Penicillium hirstum spore suspension in a cold storage room ($-2^{\circ}C$), blue mold disease on garlic bulbs was suppressed, with a control efficacy of 79.2%. These results suggested that B. pyrrocinia CAB08106-4 isolates could be used as effective biological control agents against both soil-borne and post-harvest diseases of Liliaceae. Chinese cabbage clubroot caused by Plasmodiophora brassicae was found to be highly virulent in Chinese cabbage, turnips, and cabbage. In this study, the endophytic bacterium Flavobacterium hercynium EPB-C313, which was isolated from Chinese cabbage tissues, was investigated for its antimicrobial activity by inactivating resting spores and its control effects on clubroot disease using bioassays. The bacterial cells, culture solutions, and culture filtrates of F. hercynium EPB-C313 inactivated the resting spores of P. brassicae, with the control efficacies of 90.4%, 36.8%, and 26.0%, respectively. Complex treatments greatly enhanced the control efficacy by 63.7% in a field of 50% diseased plants by incorporating pellets containing organic matter and F. hercynium EPB-C313 in soil, drenching seedlings with a culture solution of F. hercynium EPB-C313, and drenching soil for 10 days after planting. Soft rot caused by Pectobacterium carotovorum subsp. carotovorum was reported to be severe disease to Chinese cabbage in spring seasons. The antifungal bacterium, Bacillus sp. CAB12243-2 suppresses the soft rot disease on Chinese cabbage with 73.0% control efficacy in greenhouse assay. This isolate will increase the utilization of rhizobacteria species as biocontrol agents against soft rot disease of vegetable crops. Sclerotinia rot caused by Sclerotinia sclerotiorum has been reported on lettuce during winter. An antifungal isolate of Pseudomonas corrugata CAB07024-3 was tested in field bioassays for its ability to suppress scleritinia rot. This antagonistic microorganism showed four-year average effects of 63.1% of the control in the same field. Furthermore, P. corrugata CAB07024-3 has a wide antifungal spectrum against plant pathogens, including Sclerotinia sclerotiorum, Sclerotium cepivorum, Botrytis cinerea, Colletotrichum gloeosporioides, Phytophotra capsici, and Pythium myriotylum.

• The Plant Pathology Journal
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• 제17권3호
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• pp.141-148
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• 2001

Postharvest decay of onion bulbs was examined by inspecting the commercial packages in the market or in storage. Bulb rot incidence was unexpectedly high, and onion bulbs with 1st quality grade were rotten most severely by 51%, followed by 32% for 2nd and 21% for 3rd grades. This indicates that larger bulbs had higher incidences of bulb rots. Major pathogens associated with basal and neck rots were Fusarium oxysporum and Aspergillus sp. or Botrytis allii, respectively, of which basal rot was most prevalent and damaging during storage. Among the epiphytic microorgani는 from onion plants, several Bacillus and Paenibacillus spp. and previously selected Pseudomonas putida and Trichoderma harzianum had inhibitory efficacy against bulb rot pathogens. Among these B. amyloliquefaciens BL-3, Paenibacillus polymyxa BL-4, and P. putida Cha 94 were highly inhibitory to conidial germination of F. oxysporum and B. allii. P. putida Cha 94, B. amyloliquefaciens BL-3, P. polymyxa BL-4, and T. harzianum TM were applied in the rhizoplane of onion at transplanting. Initially antagonist populations decreased rapidly during the first one month. However, among these antagonists, rhizoplane population densities of BL-3, Cha 94, and TM were consistently high thereafter, maintaining about 10$^4$-10$^{5}$ cells or spores per gram of onion root up to harvest time. The other bacterial antagonist BL-4 survived only for two months. TM was the most effective biocontrol agent against basal rot, with the number of rotten bulbs recorded at 4%, while that of the control was 16%. Cha 94 was effective for the first 20 days, but basal rot increased thereafter and had about the same control efficacy as that of BL-3 and BL-4. When the antagonists were applied to the topping areas of onion bulbs at harvest, TM was the most effective in protecting the stored onion bulbs from neck rotting. The second effective antagonist was BL-3. TM and BL-3 completely suppressed the neck rot in another test, suggesting that biocontrol of postharvest decay of onion using these microorganisms either at the time of transplanting or at harvesting may be promising.

• 한국유기농업학회지
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• 제17권1호
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• pp.83-94
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• 2009

양송이버섯 재배 후 문제가 되고 있는 폐상퇴비는 다음 버섯 재배의 촉박성 때문에 폐상하여 재배사 주변에 방치하는 경우가 많으며, 이들은 병해충 및 수질오염의 원인이 됨으로 신속한 처리가 필요하다. 폐상된 양송이재배 부산물에는 형광성 Pseudomonas속, 방선균 등 다양한 미생물이 분포하였고, 양송이 재배농가별로 폐상퇴비 중의 미생물상 차이가 많았다. 폐상퇴비에서 분리한 세균들은 토마토 시들음병균. 풋마름병균에 대해 길항성을 보였다. 농가별 양송이 폐상퇴비의 이화학성은 pH는 $5.8{\sim}6.7$이었고, EC는 $316{\sim}528\;dS\;m^{-1}$로 농가마다 많은 차이를 보였고, T-N의 농도는 $151{\sim}1.99%$, $P_2O_5$은 $0.27{\sim}0.55%$, $K_2O$은 $1.71{\sim}3.57%$, CaO는 $1.79{\sim}5.85%$, MgO는 $0.88{\sim}1.33%$였다. 양송이 폐상퇴비의 농가실증 시험결과 시기별 토마토의 생육과 당도는 농과관행퇴비 처리구와 뚜렷한 차이가 없었고 생육시기별 토양이화학성은 농가관행에 비해 EC와 K, Ca는 증가하였지만, 인산은 감소하였다. 처리별 토양미생물상의 변화에는 차이가 없었으며, 수량은 농가관행구에 비해 약간 감소하는 경향을 보였다. 풋마름병 발병률은 무처리에 비해 폐상퇴비 처리구에서 상대적으로 낮았다.

• 생명과학회지
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• 제16권1호
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• pp.108-113
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• 2006

독성물질의 무독화 연구의 화학적 분석방법의 문제점을 보완하고, 난분해성 독성물질의 분해 미생물을 효율적으로 탐색하기 위해, 지렁이와 microplate를 이용한 빠르고 간편한 독성평가 시스템을 구축하였다. 본 방법은 지렁이의 사육이나 특수시설이 필요하지 않으며, 치사 및 무게감소가 현저하게 나타나지 않는 저농도, 단기간 처리시에도 신속하게 독성의 정량평가가 가능하다 실제 endosulfan 및 다양한 endosulfan 유도체, 구조적 유사체 등을 대상으로 독성 평가한 결과, endosulfan, endosulfan sulfate, aldrin 및 dieldrin 에서만 독성이 나타나 기존의 연구결과와 잘 일치하였다. 이를 이용하여 endosulfan분해 및 무독화 균주 선별을 시도한 결과, 기존 endosulfan분해 및 무독화 균주로 선별된 KE-1, KE-8, KS-2P균주 처리의 경우에는 지렁이의 독성이 거의 나타나지 않았으나, E. coli, B. subtilis, 및 YSU 균주들을 처리한 경우에는, 지렁이 사멸과 함께 심각한 독성이 나타났다. 따라서, 본 시스템은 독성물질의 독성평가뿐 아니라, 독성물질의 분해 및 무독화 미생물 선별에 매우 유용함을 확인하였다.