• 한국유기농업학회지
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• 제6권1호
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• pp.133-149
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• 1997

Recently, the importance of management and cultivation of grasses has been increased in Korea. Among these cultural practices, the appropriate control of diseases is considered more important than other cultivation techniques such as fertilization and irrigation. The damages of brown patch and large patch caused by Rhizoctonia spp. and Pythium blight caused by Pythium spp. are serious in the major cultivation area of turfgrass in Korea. Since these diseases are difficult to control by agrochemicals, the damages are very serious if these are occured. The periodic spray of agrochemicals, to protect and control these diseases could make some problems of toxicity and environmental pollution as well as rising of non-target diseases. Therefore, the biological methods to control diseases have been required to decrease problems resulted from overuse of agrochemicals, to conserve natural ecosystem, and to control effectively diseases of grasses in the long period. The number of studies about biological control using antagonistic microorganisms have been increased for last half century. However, the application of biological control method has been very limited. In this study, thirteen isolates of R. cerealis, 8 isolates of R. solani and 3 isolates of Phthyn spp. have been isolated from diseased turfgrass in golf course and grass-culture area that have patch and wilting symptoms of zoysia grass and creeping bentgrass. Isolation frequency of R. cerealis and R. solani was high in especially zoysiagrass, while Pythym spp. was isolated from bent grass at low frequency but showed high pathogenicity. Totally, 205 isolates of soil microorganisms were isolated in this study as primary antagonistic microorganism by Herr's triple agar layer plate and dual culture method using rhizosphere of grasses, soil of crop field as the source of antagonistic microorganisms. Among the 205 isolates, 23 isolates were actinomycetes and 182 isolates were bacteria. All of the actinomycetes were isolated by Herr's method. Antagonistic effect of primary isolated microorganisms was tested for in vitro mycelial growth inhibition against pathogenic fungi isolated from grasses and for inhibition of disease occurrence in 24 well tissue culture plate and pot experiment. Then, four isolated of bacteria which are BG23, BG74, BG136 and BG171 were selected as antagonistic microorganisms against soil-born pathogenic fungi of bentgrass.

• The Plant Pathology Journal
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• 제24권1호
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• pp.58-62
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• 2008

Utilization of carbon sources by Bacillus cereus D324, a biological control agent, and Pythium species, which causes rice seedling disease, was studied with the objective of increasing the efficacy of biological control by providing the biological control agent with specific beneficial carbon sources. D-galactose, D-sorbitol, and D-mannitol were poor carbon sources for Pythium spp. growth but were good for B. cereus D324 growth. Growth in a growth chamber of rice seeds coated with B. cereus D324 amended with specific carbon sources, such as D-galactose and D-sorbitol, showed significantly enhanced seedling emergence compared to seeds coated only with B. cereus D324. Field trials showed that both seedling emergence and yield increased, when the above specific carbon sources were added to B. cereus D324 in seed coating formulations. This result indicated that amending seed coating formulations with specific carbon sources could significantly increase seedling emergence and yield in the field.

• 한국연초학회지
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• 제13권1호
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• pp.53-60
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• 1991

Seedling rot occurred on burley tobacco at the early growing stage after transplanting was surveyed in the Chonbuk province, the main area for burley tobacco production, during the 3 crop years from 1986. The incidence of disease was about 0.6-0.7% every year and major causal organisms were Pythium spp. More diseased plants were observed in the fields in which tobacco planted with improved mulching system than in that with any other mulching system. The temperature and relative humidity in the planting hole covered with polyethylene film for 11 days after transplanting were recorded by 27-45$^{\circ}C$ and 75~95%, respectively. The punched polyethylene film mulching field showed less diseased plants than that with improved mucking. In improved mulching system the longer period of mulching caused higher incidence of seedling rot(r=0.74**). Soil drench treatment of 200m1 of aqueous Metalaxyl Solution(125ppm) was effective to control the disease.

• Applied Biological Chemistry
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• 제46권2호
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• pp.79-83
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• 2003

난균류에 속하는 Phytophthora spp.와 pythium spp.에서 분비되는 단백질인 elicitin은 식물과 병원균과의 비친화적 관계에서 과민감반응을 유도하는 인자로 알려져 왔다. 국내에서 수집된 5종의 Phytophthora spp로부터 분리된 elicitin들은 무, 배추, 고추에서 과민감 반응을 유도 하였으나 오이, 토마토에서는 볼 수 없었다. 특히 지금까지 보고가 되지않은 P. cambivora KACC 40160균주의 배양액으로부터 ion exchange와 gel filtration을 이용하여 고추에 과민감반응을 유도하며 분자량이 10kDa인 새로운 elicitin을 순수분리 하여 cambivorein이라 명명 하였다. 분리된 cambivorein의 N-말단 아미노산 서열분석 결과 ${\beta}-isoform$의 특징인 13번째 아미노산이 Iysine을 가지고 있었으며 기존의 다른 종류의 elicitin과는 다른 아미노산으로 구성되어 있었다.

• 아시안잔디학회지
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• 제24권2호
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• pp.117-124
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• 2010

한지형 잔디 6종류의 45품종에 대하여 여름철 갈색마름병의 발생과 잔디생존율을 평가하였다. 갈색마름병의 발생율은 7월에 2회 조사를 하였으며, 잔디생존율은 8월과 9월사이에 조사를 하였다. 여름철 갈색마름병의 발생율과 잔디생존율에서 잔디종류별 품종 간에 통계적인 유의성이 차이가 크게 나타났다. rDNA ITS 동정에 의한 갈색마름병원균인 Rhizoctonia spp. 와 Pythium aphanidermatum에의한발병율은 Creeping Bentgrass 품종과 Chewings fescue 품종이 가장 약하였다. 잔디의 생존율도 Creeping Bentgrass 품종과 Chewings fescue 품종이 가장 약하였다. Kentucky bluegrass종은 20 품종 중 "Nuglade", "Cabernet", "Midnight II" 및 "Beyond" 품종이 생존율이 가장 좋았고, Tall fescue 종은 "Double sentry"와 "Inferno" 두 품종에서 생존율이 가장 좋았으며, Perennial ryegrass 종은 2품종 중 "Accent II" 품종이 생존율이 가장 높았다.

• 아시안잔디학회지
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• 제25권1호
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• pp.48-51
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• 2011

본 연구는 SCB저농도액비의 기능성향상을 위한 섬유소분해 미생물균주를 탐색하고 선발하기 위해 수행되었다. 예초물 퇴비에서 섬유소분해 미생물균주는 배양 및 형태적 특성에 따라 5개의 균주를 선발하였다. 선발된 섬유소 분해 미생물균주의 배지에 따른 균생장은 TSB배지에서 배양할 때 균의 생장속도가 가장 높게 나타났다. 섬유소분해 미생물균주를 SCB저농도액비에 접종한 결과, 접종 후 18시간에는 균생장이 거의 이루어지지 않다가 24시간이 지나면서 급격히 증가하여 36시간 후에 균생장이 최고조를 이룬 뒤 48시간 이후에는 사멸기가 시작되는 것으로 조사되었다. NB배지에서 보다 TSB배지에서 CDMs의 생장속도가 빠른 것으로 조사되었다. 주요 잔디병원균에 대한 항균력을 검정한 결과 Sclerotinia homoeocarpa, Rhizoctonia solani AG2-2(IV)와 Pythium spp.에서 CDMs을 첨가한 SCB 저농도액비는 각각 14.1, 11.0, 26.8% 균사생장이 억제되었다. 통계적인 유의차는 없었으나, 잔디 퇴비에서 선발된 CDMs을 배양한 SCB저농도액비를 지속적으로 코스관리에 이용한다면 일부 잔디병원균에 효능이 있을 것으로 기대된다.

• 아시안잔디학회지
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• 제20권1호
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• pp.57-63
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• 2006

이 연구는 식물유래 천연물, TGR-N1의 잔디진균병에 대한 방제효과를 조사하기 위해 수행되었다. In vitro실험에서 TGR-N1은 잔디진균병에 대해 항균효과를 나타내었다. TGR-N1의 500배, 1000배액은 Rhizoctonia solani AG 1-1, Rhizoctonia solani AG2-2, Rhizoctonia cerealis, Sclerotinia homoeocarpa, Colletotrichum graminicola 에 대해 강한 항균력을 나타내었다. 그러나 Pythium spp.에 대해서는 항균효과가 없었다. TGR-N1의 Rhizoctonia solani AG 1-1, Rhizoctonia solani AG2-2에 대한 포장방제 실험결과, TGR-N1 500배액의 방제가는 각각 86.1%와 83.3%의 방제가를 나타내었다. 이 연구 결과 식물유래 천연물 TGR-N1의 항균 활성이 확인되었는 바 천연물 농약으로서의 잠재성을 보여 주었다.

• The Plant Pathology Journal
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• 제15권5호
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• pp.287-294
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• 1999

A technique based on the polymerase chain reaction (PCR) for the specific detection of genus Phytophthora and Phytophthora cryptogea-P. drechsleri complex group was developed using nucleotide sequence information of ribosomal DNA (rDNA) regions. The internal transcribed spacers (ITS) including 5.8S were sequenced for P. cryptogea-P. drechsleri complex group and its related species. Two pairs of oligonucleotide primers were designed. Primer pair ITS1/Phy amplified ca. 240 bp fragment in 12 out of 13 specie of Phytophthora, but not in Pythium spp., Fusarium spp.and Rhizoctonia solani. Primer pair rPhy/Pcd amplified 549 bp fragment only in P. cryptogea-P. drechsleri complex group, but not in other Phytophthora spp.and other genera. Specific PCR amplification using the primers was successful in detecting Phytophthora and P. cryptogea-P. drechsleri complex group in diseased plants.

• ALGAE
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• 제38권1호
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• pp.71-80
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• 2023

The oomycete pathogens Pythium porphyrae, causing red rot disease, and Olpidiopsis spp. causing Olpidiopsis-blight, cause serious economic losses to Pyropia sea farms in Korea. During the washing step for Pyropia processing, these pathogens proliferate rapidly, significantly reducing the quality of the final product. To develop non-acidic treatments for these pathogens, various calcium salts were tested against the infectivity of P. porphyrae and Olpidiopsis pyropiae on Pyropia gametophytes, and calcium propionate was the most effective. When Pyropia blades were immersed in 10 mM calcium propionate for 1 h after inoculation with the oomycete pathogen, infection rate of both oomycete pathogens on day 2 was significantly lower (7.1%) than control (>95%). Brief incubation of Pyropia blades in calcium propionate also reduced the spread of infection. The infected area of Pyropia thallus was reduced to 14.3% of the control in 2 days after treatment with 100 mM calcium propionate for 30 s. In field experiments conducted in actual aquaculture farms, it has been shown that a brief 30 s wash every two weeks with 100 mM calcium propionate can effectively reduce the spread of oomycetes throughout the entire culture period. The above results suggest that calcium propionate can be a useful means for controlling the spread of oomycetes not only during laver processing but also during aquaculture.

• 원예과학기술지
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• 제16권3호
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• pp.347-349
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• 1998

본 실험은 국내 농가에서 가장 적용하기 간편하고 효율적인 모래여과(slow sand filtration)방법을 기초로 하였으며, 여러 가지 여과용 매질을 적용하여 병원균 제거 효율을 검정하고자 하였다. 양액 1,500 liter 여과후, 매질별 균 제거효율은 Fusarium oxysporum을 기준으로 볼 때, 활성탄 92.5%, 석영모래 90.8%, 버미큘라이트 90.5%, 강모래 82.3%, 펄라이트 50.4%, 하이드로볼 21.2% 순으로 나타났고, 균주별 시험의 경우, 석영모래를 기준으로 여과액에서 검정되는 최대 농도가 Fusarium oxysporum 120 cfu/mL. Collectotrichum lagenarium 98 cfu/mL. Phytophthora capsici 82 cfu/mL, Botrytis cinerea 62 cfu/mL, Pythium spp. 42 cfu/mL, Sclerotinia spp. 52 cfu/mL로 나타났다. 여과후, pH 및 EC의 변화는 석영모래를 기준으로 볼 때, pH는 약 7로유지되었고, EC 는 큰 차이가 없었다. '뚝섬 적축면' 상추와 '서광' 토마토를 담액수경으로 재배하며, 석영모래, 활성탄, 버미큘라이트를 충진물로 한 여과시스템을 적용한 결과, 균을 인위접종 후 10주 후까지 발병하지 않아, 본 여과시스템으로 효과적인 균제거가 가능함을 보여주었다. 실제 농가수준에서도 본 시스템을 적용할 경우, 균 제거능 및 경제성에 있어 효율적이라 사료된다.