Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). To monitor contamination with C. destructans in ginseng harvested in 2015 were sampled from 57 different growing fields. The spore number of C. destructans was quantified by use of a specific primers and selective media (radicicol) in soils of ginseng fields. Methods and Results : The ginseng samples were surface-sterilized and placed on potato dextrose agar plates for 7 day incubation at 20℃. Emerging fungal colonies were counted primarily based on colony and conidia morphology. Further species level identification was confirmed by ITS rDNA sequencing. For quantification of the soil-borne C. destructans, the genomic DNA was extracted from the soil using a NucleoSpin soil kit (MN, Germany). Density of C. destructans was determined by species specific real time PCR (qPCR). The qPCR was completed by running a melting curve analysis. Conclusion : The C. destructans associated with root rot disease of ginseng were detected in more than 60% in pyeongtaek-1, pochenon-1, jecheon-1, chungju-1 and jinan-4. As results of the study, the correlation between pathogen density and identification clearly clarified in the soil.

The SS (Bacillus subtilis 10%), WS (Microbial extract 70%), and DS (Sulfur 78%) agents were selected by mycelial growth inhibitory effect test against kiwifruit soft rot pathogen (B. dothidea) with 11 kinds of environment-friendly agricultural materials on PDA medium for 10 days. They showed at 94.2%, 65.2%, 58.9%, respectively. The control value of WS and SS agents were better than DS in storage experiment. It was effective SS and WS single application, DS-WS and WS-SS alternate application in the field trial.

To develop environment-friendly agricultural products with anti-microbial activity against Sclerotinia sclerotiorum as a pathogen of sclerotium disease, Aristolochia tagala Champ. was extracted by methanol and its extract was fractionated into several solvent fractions. The chloroform fraction, which showed the highest antimicrobial activity, was separated by column chromatography and obtained forty three subfractions. The forty three fractions were searched the anti-fungal activities by bioassay. The most active No. 26 subfraction was analyzed by GC-MS. Each mass spectra, corresponding to each peak of chromatogram, was compared to MS database of Wiley library. As a result, 2,4-di-tetra-butyl-phenol, 2-mono-palmitin, 1-mono-stearin were profiled as maine compounds in No. 26 subfraction. Bioassay using commercial 1-mono-stearin to test for the anti-microbial activity conformed the antimicrobial active compound. In conclusion, 1-mono-stearin identified from Aristolochia tagala Champ. was antimicrobial chemical against Sclerotinia sclerotiorum.

To develop environment-friendly agricultural products with anti-microbial activity against Sclerotinia sclerotiorum as a pathogen of sclerotium disease, Usnea longissima was extracted by methanol and its extract was fractionated into several solvent fractions. The chloroform fraction, which showed the highest antimicrobial activity, was separated by silica gel-column chromatography and obtained into nine group subfractions. The nine group fractions were searched the antifungal activities by bioassay. The most active No. 3 subfraction was analyzed by GC-MS. Each mass spectra, corresponding to each peak of chromatogram, was compared to database of Wiley library. As a result, Usnic acid was identified as main compounds. In conclusion, Usnic acid isolated from Usnea longissima was antimicrobial chemical against Sclerotinia sclerotiorum as a pathogen of sclerotium disease.

It is necessary to evaluate the resistance to disease among genetic resources for development of disease resistant grapes. This study was conducted to screen the resistance to crown gall in muscadine and Florida hybrid bunch grapes by pathogen inoculation. In order to compare the responses to infection with different pathogen strains, muscadine and Florida hybrid grapes were inoculated with 3 strains of Agrobacterium vitis. Although there were different levels crown gall formation among grape cultivars, there little variation in response to inoculated strains. Among 29 muscadine cultivars tested by inoculation of A. vitis ‘C4612’, most of them were shown to be susceptible, and ‘Gold Isle’ and ‘Africa Queen’ were highly susceptible, and two cultivars, ‘Welder’ and ‘Jumbo’ were found to be resistant to crown gall disease. Among Florida hybrid grapes, ‘Daytona’, ‘Stover’, and ‘Swanee’ were susceptible and ‘Blanc du Bois’ was moderately susceptible to crown gall. Because muscadine grapes have been actively utilized as useful genetic resources for development of new grape varieties by intersub-genus cross, this result from the screening of resistance among muscadine grapes can provide valuable information in breeding programs of grape resistant to crown gall.

본 연구는 수박 과실썩음병의 원인균인 A. avenae subsp. citrulli에 대해 항균활성을 갖는 친환경 유기농자재를 개발할 목적으로 오배자(S. chinensis)를 대상으로 수행되었다. 오배자를 MeOH로 추출하여 용매분획을 하였고, 용매분획 중에서 가장 강한 활성을 나타낸 hexane fraction을 column chromatography로 분리하여 활성이 강한 분획들을 GC-MS로 분석하였다. GC chromatogram 상의 주요 peak에 해당하는 mass spectrum과 Wiley library를 비교하여 profiling한 결과, 지방산인 myristic acid, palmitic acid와 3-n-pentadecylphenol이 주요 물질로 검출되었다. 이들 검출 화합물의 항균활성을 검정하기 위하여 표준품을 사용하여 bioassay한 결과, myristic acid와 3-n-pentadecylphenol 화합물이 강한 활성을 보였다. 따라서 오배자로부터 분리한 myristic acid와 3-n-pentadecylphenol 화합물이 항균 활성물질인 것을 구명하였다.

본 연구는 수박 과실썩음병의 원인균인 Acidovorax avenae subsp. citrulli 균에 대해서 항균활성을 갖는 친환경 유기농자재를 개발할 목적으로 약용식물 133종을 대상으로 진행되었다. 이들 133종 약용식물의 MeOH 추출물에 대한 bioassay를 통해 항균 활성을 검정한 결과 청피(Citrus unshiu Markovich) 추출물에서 강한 항균활성을 보였다. 청피(Citrus unshiu Markovich)로부터 항균활성물질을 구명하고자 용매분획을 하였고, 용매분획 중에서 hexane fraction이 가장 강한 활성을 나타내었다. Hexane fraction을 GC-MS로 분석하여 chromatogram상의 각각의 peak에 해당하는 mass spectrum과 Wiley library를 비교하여 profiling 한 결과, essential oil인 d-limonene, γ-terpinene, β-linalool, terpineol과 지방산인 palmitic acid, 9,12-octadecadienoic acid, linolenic acid 그리고 steroid 화합물인 stigmasterol이 검출되었다. 이들 검출화합물 중에서 항균 활성물질로 추정되는 d-limonene, γ-terpinene, β-linalool, terpineol의 항균 활성을 검정하기 위해 표준품을 사용하여 bioassay한 결과 두 화합물 dlimonene, γ-terpinene에서 높은 항균활성을 보였다. 따라서 본 연구를 통해 청피로부터 분리한 d-limonene과 γ-terpinene 화합물이 항균 활성물질인 것을 구명하였다. 항균력이 강한 청피 추출물 또는 d-limonene과 γ-terpinene을 주성분으로 하는 추출물을 수박 과실썩음병에 대한 친환경 방제용 자제로 개발이 가능할 것으로 판단되었다.

Although several adverse effects have been increased in recent years, synthetic agro-chemicals have been widely used to control diseases on paprika. This research was conducted to isolate and to characterize the antagonistic microorganism to control major paprika diseases, gray mold rot, fruit and stem rot, phytophthora blight, sclerotium rot, and wilt disease. Analysis of the fatty acid and analysis of the 16S rDNA gene sequence revealed that YKJ2 isolated in this research belongs to a group of Burkholderia cepacia. Specially, 16S rDNA gene sequence of YKJ2 showed 99% of sequence similarity with B. cepacia. Observation through the optical microscope revealed that YKJ2 was effective on suppression of the spore germination and the hyphal growth of pathogens. YKJ2 treatment on pathogens induced marked morphological changes like hyphal swelling and degradation of cell wall. In the case of phytophthora blight, the zoosporangium formation was restrained. On the basis of the results of this study, we propose that an antagonistic microorganism, B. cepacia, found in this study naming as “B. cepacia strain YKJ2” and has great potential as one of biological control agents against major diseases of paprika.

This study aimed to evaluate the effects of probiotics as manure additives on pathogen, mineral, carbon dioxide and methane emissions in pig slurry as a function of time and provide information about the importance of pig slurry management to pig producers. An experiment was a completely randomized design and four treatments: CON: no treatment (5 kg pig slurry), T1: 5 kg pig slurry + 0.2% bacillus subtilis, T2: 5 kg pig slurry + 0.2% yeast, T3: 5 kg pig slurry + 0.2% actinomycetales. All treatments were replicated three times. The results information that is analyzed includes the following: First, in spite of the lack of statistically significant differences, pH values and carbon dioxide were lowered (P < 0.05) in all probiotic treatments compared with the controls as a function of time. Second, all probiotic treatments had no effect on Salmonella enterica, mineral, and methane emission. The results of this study indicated that addition of 0.2% probiotic to pig slurry resulted in lower pH and carbon dioxide emissions, and carbon dioxide and methane emitted from pig slurry is not listed as noxious gases.

파프리카에 발생하는 병들을 방제하기 위하여 합성농약이 광범위하게 사용되어왔지만 최근에 수많은 농약사용의 부작용에 대한 관심이 증가 하고 있다. 파프리카 주요병인 잿빛곰팡이병, 줄기 및 과실썩음병, 역병, 균핵병, 시들음병을 방제하기 위한 미생물을 분리하고 특성을 파악하기 위하여 본 연구를 실시하였다. 지방산분석과 16S rDNA 염기배열은 이 연구에서 분리한 YKJ1가 Serratia marcescens 그룹에 속하는 것을 밝혔다. 특히, YKJ1의 16S rDNA 염기배열은 S. marcescens의 염기서열과 99% 상동성을 보였다. 광학현미경을 통해 YKJ1처리에 의해 병원균의 포자 발아 및 균사 생장이 저해됨을 확인 하였다. YKJ1처리는 팽윤균사와 같은 현저한 형태적 변화와 세포벽의 분해를 유발하였다. 역병균의 경우 유주자낭의 형성이 억제되었다. 본 연구에서 동정한 S. marcescens는 S. marcescens-YKJ1으로 부르고자 한다. 포장실험등과 같은 시험이 차후 더 요구되어지나 파프리카의 주요 병관리를 위한 생물적 방제제의 하나로 가치가 있을 것으로 생각된다.

The objective of this study was to evaluate the effect of applying alum (aluminum sulfate) and aluminum chloride on pH and pathogen populations of Hanwoo manure. A total of 36 steers (8 months old and averaging 300 kg in weight) were used in this trial and allotted to 9 pens (3 replication pens per group with 4 steers per experimental unit, 5 x 8 m). Chemical additives were applied as a top dressing with garden rake to a depth of 1 cm of manure with wood shavings in each treatment. The chemical amendments were control (without chemical amendments), 50 g of alum and 50 g of aluminum chloride/kg of Hanwoo manure. The experiment was carried out for 4 weeks. Adding alum and aluminum chloride to Hanwoo manure reduced (P < 0.05) pH compared to untreated controls during the 4-wk period. Both levels of the alum and aluminum chloride treatments tested decreased (P < 0.05) Escherichia coli and Salmonella enterica populations in Hanwoo manure at 2 and 4 weeks. It appears that the reduction in pathogen populations was primarily associated with the lower manure pH. If more strict environmental regulations are put into effect regarding pathogen populations from Hanwoo facilities, treating Hanwoo manure with alum and aluminum chloride may be a good management practice.

참다래 품종 '헤이워드'와 우리나라에서 육성된 품종인 '한라골드', '제시골드', '제시스위트'를 동일한 조건에서 재배한 후 후숙 과정에서 발생하는 과실무름병의 발병률을 조사하였다. 발병률은 품종에 따라 큰 차이를 보였다. 품종별 발병률은 '헤이워드' 74.8%, '한라골드' 65.3%, '제시스위트' 57.1%, '제시골드' 16.2% 순으로 조사된 품종 중 '제시골드'가 과실무름병에 대한 저항성이 가장 컸다. 병반 부위에서 218개 균주를 분리하여 동정한 결과 과실무름병을 일으키는 병원균은 Botryspheria dothidea, Diaphorthe actinidiae, Botrytis cinerea의 세 종류로 밝혀졌다. 각 병원균의 검출률은 각각 95.4%, 4.6%, 2.3%로 B. dothidea가 과실무름병의 주요 병원균이었다.

양파 근권미생물은 양파 뿌리를 균원시료로 하여 약 250여종의 근권미생물을 순수 분리하였고 이들 중에서 길항미생물은 무름병균인 Erwinia carotovora subsp. carotovora와 시들음병균인 Fuarium oxysporium에 각각 서로 대치 배양하여 두 병원균 모두에 가장 강한 길항 효과를 나타내는 YJ-4 균주를 최종 선발하였다. 선발균주 YJ-4는 Bergey's mannual of systematic bacteriology

C. destructans는 인삼에서 가장 문제가 되고 있는 뿌리섞음병을 유발하는 매우 중요한 미생물이다. 현재까지 정상적인 인삼포장이나 폐포지에서도 이 병원균의 농도를 조사할 만한 방법이 없어 이를 쉽게 조사함으로서 인삼 예정지 관린시 도움을 줄 수 있는 새로운 방법이 절실이 요구되고 있다. 본 연구에서는 nested PCR이란 분자생물학적 방법을 이용하여 효과적으로 매우 낮은 농도의 C. destructans을 검출할 수 있는 방법을 개발하였다. 2개의 universal ITS primers(ITS5F와 ITS4R)을 사 용 하 여 Cylindrocarpon spp.의 rDNA로부터 ITS영역을 증폭하였다. 이어 C. destructans의 specific primer(Nest 1 과 Nest 2)을 사용하여 최적의 PCR조건으로 재증폭시켜 밴드를 확인하였다. 또한 이런 2번의 과정을 4개의 primer를 동시에 사용함으로서 한번에 확인할 수 있는 방법을 개발하였으며 이에 따른 PCR조건도 확립하였다. 따라서 본 방법에 의해서 인삼포장의 토양에서 채취된 매우 낮은 농도의 wild type C. destructans spore로부터 성공적으로 positive band을 확인함으로써 추후 인삼포장의 선정 및 4년생에서 6년까지(홍삼포) 재배기간등의 예측에 활용 될 것으로 생각된다.