• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1998년도 임시총회 및 학술논문발표요지
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• pp.134-137
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• 1998

최근 고급 과채류에 대한 선호도가 높아짐에 따라 네트멜론의 재배가 증가되고 있는 추세이다. 그러나 주산단지에서는 고정된 시설에서 주년 재배하므로서 연작으로 인한 토양병해충 발생이 증가되고 염류집적 등의 문제가 심화되고 있다(박, 1995). 멜론 재배기술이 비교적 앞서 있는 일본에서는 이러한 연작장해를 회피하기 위한 방법으로 격리상이나 차근시트 등을 이용한 근권제한재배에 관한 연구가 다년간 이루어져 왔다. (중략)

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 1996년도 심포지움 및 학술논문발표요지
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• pp.42-53
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• 1996

Storage methods to suppress growth of transplants and maintain their quality are required for successful commercial transplant production, since peak demand for transplants of flower or vegetable species falls during limited periods in spring and fall, due to the seasonal nature of the horticulture industry. Plug seedlings, probably due to their high planting density and limited rhizosphere, easily elongated or overgrown during the holding period before the market or greenhouse space is available. (omitted)

• The Plant Pathology Journal
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• 제21권1호
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• pp.64-67
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• 2005

The biocontrol agent Serratia plymuthica A21-4 readily colonized on the root of pepper plant and the bacterium moves to newly emerging roots continuously. The colonization of A21-4 on the pepper root was influenced by the presence ofPhytophthora capsici in the soil. When P. capsici was introduced in advance, the population density of A21-4 on the root of pepper plant was sustained more than $10^6$ cfu/g root until 3 weeks after transplanting. On the other hand, in the absence of P. capsici, the population density of A21-4 was reduced continuously and less than $10^5$ cfu/g root at 21 days after transplanting. S. plymuthica A21-4 inhibited successfully the P. capsici population in pepper root and rhizosphere soil. In the rhizosphere soil, the population density of P. capsici was not increased more than original inoculum density when A21-4 was treated, but it increased rapidly in non-treated control. Similarly, the population density of P. capsici sharply increased in the non-treated control, however the population of P. capsici in A21-4 treated plant was not increased in pepper roots. The incidence of Phytophthora blight on pepper treated with A21-4 was 12.6%, while that of non-treated pepper was 74.5% in GSNU experimental farm experiment. And in farmer's vinyl house experiment, the incidence of the disease treated with the fungicide was 27.3%, but treatment of A21-4 resulted in only 4.7% of the disease incidence, showing above 80% disease control efficacy.

• Journal of Ginseng Research
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• 제40권2호
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• pp.97-104
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• 2016

Background: Rhizobacteria play an important role in plant defense and could be promising sources of biocontrol agents. This study aimed to screen antagonistic bacteria and develop a biocontrol system for root rot complex of Panax notoginseng. Methods: Pure-culture methods were used to isolate bacteria from the rhizosphere soil of notoginseng plants. The identification of isolates was based on the analysis of 16S ribosomal RNA (rRNA) sequences. Results: A total of 279 bacteria were obtained from rhizosphere soils of healthy and root-rot notoginseng plants, and uncultivated soil. Among all the isolates, 88 showed antagonistic activity to at least one of three phytopathogenic fungi, Fusarium oxysporum, Fusarium solani, and Phoma herbarum mainly causing root rot disease of P. notoginseng. Based on the 16S rRNA sequencing, the antagonistic bacteria were characterized into four clusters, Firmicutes, Proteobacteria, Actinobacteria, and Bacteroidetesi. The genus Bacillus was the most frequently isolated, and Bacillus siamensis (Hs02), Bacillus atrophaeus (Hs09) showed strong antagonistic activity to the three pathogens. The distribution pattern differed in soil types, genera Achromobacter, Acidovorax, Brevibacterium, Brevundimonas, Flavimonas, and Streptomyces were only found in rhizosphere of healthy plants, while Delftia, Leclercia, Brevibacillus, Microbacterium, Pantoea, Rhizobium, and Stenotrophomonas only exist in soil of diseased plant, and Acinetobacter only exist in uncultivated soil. Conclusion: The results suggest that diverse bacteria exist in the P. notoginseng rhizosphere soil, with differences in community in the same field, and antagonistic isolates may be good potential biological control agent for the notoginseng root-rot diseases caused by F. oxysporum, Fusarium solani, and Panax herbarum.

• 식물병연구
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• 제15권2호
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• pp.101-105
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• 2009

Serratia plymuthica A21-4는 양파(Allitum fistulosum L.) 근권에서 분리된 고추 역병 생물적 방제 미생물이다. 토양 환경이 S. plymuthica A2l-4 근권정착에 미치는 영향을 알아본 결과 사질이 많이 포함되어 공극이 많은토양에 3% 중량(w/w)의 부숙된 옥수수 줄기를 첨가하고 토양 수분함양이 40% 정도, 토양온도가 $20^{\circ}C$, 토양 pH가 중성이거나 약산성 토양이 S. plymuthica A2l-4의 근권정착에 유리하였다. 그리고 토착미생물이 있는 것이 살균한 토양에서 보다 S. plymuthica A21-4의 근권정착에 유리하였다.

• The Plant Pathology Journal
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• 제21권1호
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• pp.68-72
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• 2005

The production of antibiotic substances by Serratia plymuthica A21-4 was greatly enhanced by modifying components of a growth medium. When the minimal medium containing $K_2HPO_4$ 0.7%, $KH_2PO_4$ 0.2%, $(NH_4)_2SO_4$ 0.1%, $MgSO_4$ 0.01% was used as basal medium, the best carbon source for antibiotic production was glycerol and the most favorable nitrogen source was ammonium sulfate. The modified medium for antibiotic production also increased colonization ability of A21-4 on pepper root and in the rhizosphere soil. When the cells of A21-4 were suspended in modified medium, the population density of A21-4 on pepper root was 10-100 times higher than that suspended in 0.1 M $MgSO_4$. The population density of A21-4 on root did not decrease under $10^6$ cfu/groot up to 21 days after treatment although the inoculum of A21-4 was reduced to $10^7$ cell/ml. Similar tendency was also observed in the rhizosphere soil. Consequently, Phytophthora blight of pepper was successfully controlled by A21-4 with $10^7$ cell/ml suspended in the modified buffer solution instead of $10^9$ cfu/ml suspended in 0.1 M $MgSO_4$.

• 식물병연구
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• 제16권1호
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• pp.35-40
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• 2010

식물근권에서 유래된 12개의 근권세균이 Phytophthora citrophthora에 의해 발생되는 감귤 역병에 대해 감귤 열매에서 병진전 억제 효과를 나타내는지 조사하였다. 조사한 근권세균 중 THJ609-3, TRH423-3, BRH433-2, Lysochit 및 KRY505-3 등에 의해 역병이 억제되는 것을 역병균의 in vivo 상처접종을 통하여 밝혀졌다. 근권세균을 P.citrophthora의 균사체와 대치 배양하여 역병균 저지대의 길이를 측정한 결과 역병 진전억제효과를 보였던 5개의 균주에서 모두 항진균활성이 나타났다. 그러나 근권세균의 균사생장억제효과와 역병억제효과 사이에 양의 상관관계는 성립되지는 않았다. 한편, 근권세균 rDNA의 internal transcript spaces(ITS)을 분석을 통해 동정 한 결과 Lysochit과 KRY505-3은 Bacillus cereus로 동정 되었고, BRH4332은 B. circulans로, TRH423-3는 Burkholderia gladiol로 동정되었다. 이 연구는 친환경 농가와 같이 농약사용이 제한된 농장에서 감귤 역병에 대해 생물적 방제를 위한 활성균을 모색하는데 매우 가치가 있을 것으로 생각된다.

• 한국토양비료학회지
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• 제47권3호
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• pp.141-146
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• 2014

The necessity to develop economical and eco-friendly technologies is steadily increasing. Plant growth promoting rhizomicrobial strains PGPR are a group of microorganisms that actively colonize plant roots and increase plant growth and yield. Pot experiments were used to investigate the potential of some rhizobacterial strains to enhance the Brassica rapa growth. Microbial strains were successfully isolated from the rhizosphere of Panax ginseng and characterized based on its morphological and plant growth promotion characters. Surface disinfected seeds of Wisconsin Fast B. rapa were inoculated with the selected PGPR microorganisms. The different pots treatments were inoculated by its corresponding PGPR ($10^7cfu\;mL^{-1}$) and incubated in the growth chamber at $25^{\circ}C$ and 65% RH, the light period was adjusted to 24 hours (day). NPK chemical fertilizer and trade product (EMRO, USA) of effective microorganisms as well as un-inoculated control were used for comparison. Plants harvested in 40 days were found to have significant increase in leaf chlorophyll units and plant height and also in dry weight of root and shoot in the inoculated seedlings. Root and shoot length and also leaf surface area significantly were increased by bacterial inoculation in sterile soil. The study suggests that Rhodobacter capsulatus and Azotobacter chroococcum are beneficial for B. rapa growth as they enhance growth and induced IAA production and phosphorus solubilization. This study presents some rhizomicrobial strains that significantly promoted growth of Wisconsin Fast Plant B. rapa in pot experiment under different soil conditions.

• Journal of Ecology and Environment
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• 제33권2호
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• pp.133-139
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• 2010

Atmospheric $CO_2$ concentrations have increased exponentially over the last century and, if continued, are expected to have significant effects on plants and soil. In this study, we investigated the effects of elevated $CO_2$ on the growth of Pinus densiflora seedling and microbial activity in soil. Three-year-old pine seedlings were exposed to ambient as well as elevated levels of $CO_2$ (380 and 760 ppmv, respectively). Growth rates and C:N ratios of the pine seedlings were also determined. Dissolved organic carbon content, phenolic compound content, and microbial activity were measured in bulk soil and rhizosphere soil. The results show that elevated $CO_2$ significantly increased the root dry weight of pine seedling. In addition, overall N content decreased, which increased the C:N ratio in pine needles. Elevated $CO_2$ decreased soil moisture, nitrate concentration, and the concentration of soil phenolic compounds. In contrast, soil enzymatic activities were increased in rhizosphere soil, including ${\beta}$-glucosidase, N-acetylglucosaminidase and phosphatase enzyme activities. In conclusion, elevated $CO_2$ concentrations caused distinct changes in soil chemistry and microbiology.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2004년도 International Symposium
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• pp.29-35
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• 2004