• Journal of Microbiology and Biotechnology
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• 제30권5호
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• pp.708-716
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• 2020

The purpose of this study was to identify strawberry wilt pathogens and evaluate the efficacy of Chlorella fusca CHK0059 for improving plant growth and suppressing Fusarium wilt. We identified 10 isolates of wilt pathogens of non-pesticide Seolhyang strawberry plant, including Fusarium oxysporum f. sp. fragariae, using morphological and molecular analysis. On the 15^th day after 0.4% CHK0059 treatment, the plant height of the untreated control strawberry plants was significantly greater than that of the CHK0059-treated strawberry plants. After 85 days, both treatments showed a similar tendency regarding the height of the strawberry plants. However, the thickness of strawberry leaves treated with the CHK0059 was found to be 1 mm thicker than that of the untreated control. The flowering percentage of the CHK0059 plants was also 40.2% higher on average than that of the untreated control. The chlorophyll content of strawberry leaves treated with the CHK0059 was also, on average, 6.63% higher than that of the untreated control. After 90 days of the CHK0059 treatment, the incidence of Fusarium wilt in the CHK0059-treated plants had reduced by 9.8% on average compared to the untreated control. The population density of F. oxysporum f. sp. fragariae was also reduced by approximately 86.8% in the CHK0059-treated plants by comparison to the untreated control at 70 days after treatment. The results indicate that the microalga C. fusca CHK0059 is an efficient biological agent for improving strawberry plant growth and suppressing Fusarium wilt disease in organic strawberries.

• Journal of Microbiology and Biotechnology
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• 제19권5호
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• pp.520-524
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• 2009

Two isolates, Bacillus sp. BS87 and RK1, selected from soil in strawberry fields in Korea, showed high levels of antagonism towards Fusarium oxysporum f. sp. fragariae in vitro. The isolates were identified as B. velezensis based on the homology of their gyrA sequences to reference strains. BS87 and RK1 were evaluated for control of Fusarium wilt in strawberries in pot trials and field trials conducted in Nonsan, Korea. In the pot trials, the optimum applied concentration of BS87 and RK1 for pre-plant root-dip application to control Fusarium wilt was $10^5$ and $10^6$ colony-forming units (CFU)/ml, respectively. Meanwhile, in the 2003 and 2005 field trials, the biological control efficacies of formulations of RK1 were similar to that of a conventional fungicide (copper hydroxide) when compared with a non-treated control. The RK1 formulation was also more effective than BS87 in suppressing Fusarium wilt under field conditions. Therefore, the results indicated that formulations of B. velezensis BS87 and RK1 may have potential to control Fusarium wilt in strawberries.

• 식물병연구
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• 제24권4호
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• pp.257-264
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• 2018

딸기 수경재배시스템은 국내에서 매년 증가추세에 있다. 대부분의 딸기농가는 수경재배에서 베드를 멀칭하여 9월 초순 딸기묘를 정식한다. Fusarium oxysporum f. sp. fragariae에 의한 시들음병과 점박이응애 Tetranychus urticae는 정식 후 높은 온도조건에서 발생이 증가하는 경향이 있다. 따라서 베드 녹색 polyethylene(PE)필름 멀칭과 무멀칭처리에서 시들음병과 점박이응애 발생을 비교하기 위해 시험을 실시하였다. 녹색 PE필름 멀칭처리에서 시들음병 발생은 10월 초순부터 시작되었고 무멀칭처리보다 더 증가하였다. 녹색 PE피름 멀칭 처리는 점박이응애의 피해율이 무멀칭처리보다 높았다. 녹색 PE필름 멀칭처리의 상토내 온도는 무멀칭처리보다 증가했지만 대기내 상대습도는 감소하였다. 이런 결과로 딸기 수경재배에서 베드의 무멀칭처리는 시들음병과 점박이응애 발생을 낮추는 효과가 있다고 판단된다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.118-118
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• 2003

The occurrence of Fusarium wilt in strawberry fields in Korea was assessed from 2001 to 2003. Fusarium wilt was found from June to August in nursery beds, from September to October after planting in production beds, and from January to March during harvest. The symptoms seen were root rots, discolored vascular tissue in the crown and deformation and yellowing of central leaflets. The disease occurred in up to 30％ of plants in 37 of 214 fields surveyed. Fusarium of sporum Schlecht. ex Fr. f. sp. fragariae was frequently isolated from cvs. Dochiodome, Maehyang, Redpearl, Samaberry and Akihime. Factors affecting the occurrence of Fusarium wilt were investigated; infested soils had high salt concentrations, low pH, OM, average P2O5 and exchangeable. Fusarium wilt was more frequent following conventional basal fertilization than after non-nitrogen basal fertilization and more frequent following the use of NH4-N than after NO3-N.

• 식물병연구
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• 제24권1호
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• pp.26-32
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• 2018

Fusarium oxysporum f. sp. fragariae (Fof)에 의한 딸기 시들음병은 국내에서 중요한 병해이다. 특히 딸기재배에서 시들음병 발생은 수경재배 면적이 증가하면서 증가하는 경향을 보이고 있다. 따라서 이 연구에서는 딸기 수경재배에서 시들음병 발생에 배양액의 pH와 EC의 영향을 in vitro와 재배포장에서 조사하였다. pH는 5, 5.5, 6, 6.5, 7, 7.5로 in vitro와 재배포장에서 검정하였고 EC는 0, 0.5, 0.8, 1, $1.5dS{\cdot}m^{-1}$로 재배포장에서 조사하였다. In vitro 상에서 딸기 시들음병균의 균사생육은 pH가 증가하면서 증가하였고 $25^{\circ}C$, pH 7에서 최대였으며 $20^{\circ}C$, pH 5에서 가장 낮았다. 재배포장에서 딸기 시들음병 발생은 pH 6.5에서 가장 낮았고 pH 5에서 가장 높은 경향을 보였다. 배양액의 pH는 높아질수록 배액의 EC는 감소하였고 딸기 잎의 칼륨함량은 증가되었다. EC 검정에서 배양액 EC가 상승함에 따라 딸기 시들음병 발생과 잎의 질소함량은 증가하였다. 이런 결과로 딸기 시들음병 발생은 수경재배에서 pH와 EC가 관련이 있다는 것을 알 수 있었다.

• 한국식물병리학회지
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• 제11권4호
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• pp.298-303
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• 1995

The biological control effect of Trichoderma harzianum on the Fusarium wilt of strawberry and several factors affecting on its efficacy were examined through pot experiments. T. harzianum grown on wheat barn, rice straw, rice hull, sawdust or barley straw was respectively incorporated into the pathogen-infected soil, and significantly suppressed the strawberry wilt caused by Fusarium oxysporum f. sp. fragariae. The wheat bran or rice straw culture of T. harzianum suppressed the disease incidence more effectively than other substrates for culture, decreasing it to 68% of the untreated control. The conidial suspension of T. harzianum alone or the suspension mixed with crab shell also effectively reduced the disease incidence. The control effectiveness of T. harzianum was high in acid soil (pH 3.5~5.5). In sandy loam soil, the disease incidences and population densities of the pathogen were decreased by the treatment of T. harzianum, while there was no significant effect of T. harzianum on the pathogen in loam soil.

• The Plant Pathology Journal
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• 제33권2호
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• pp.140-147
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• 2017

Fusarium wilts of strawberry, caused by Fusarium oxysporum f. sp. fragariae, is a serious soil-borne disease. Fusarium wilt causes dramatic yield losses in commercial strawberry production and it is a very stubborn disease to control. Reliable chemical control of strawberry Fusarium wilt disease is not yet available. Moreover, other well-known F. oxysporum have different genetic information from F. oxysporum f. sp. fragariae. This analysis investigates the genetic diversity of strawberry Fusairum wilt pathogen. In total, 110 pathogens were isolated from three major strawberry production regions, namely Sukok, Hadong, Sancheong in Gyeongnam province in South Korea. The isolates were confirmed using F. oxysporum f. sp. fragariae species-specific primer sets. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analyses were executed using the internal transcribed spacer, intergenic spacer, translation elongation factor1-${\alpha}$, and ${\beta}$-tubulin genes of the pathogens and four restriction enzymes: AluI, HhaI, HinP1I and HpyCH4V. Regarding results, there were diverse patterns in the three gene regions except for the ${\beta}$-tubulin gene region. Correlation analysis of strawberry cultivation region, cultivation method, variety, and phenotype of isolated pathogen, confirmed that genetic diversity depended on the classification of the cultivated region.

• 한국식물병리학회지
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• 제1권1호
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• pp.28-32
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• 1985

딸기$\cdot$시들음병에 대한 실용적인 약제방제법을 규명하기 위하여 본 시험을 실시하였다. 이 균이 균사생장과 후막포자 발아의 저지효과에 있어서 Captafol이 가장 효과적이었으며 Benomyl도 저지효과가 현저하였다. 포장시험에서는 Captafol, Benomyl, Thiophanate-methly의 토양근주의 효과가 비교적 우수하였다. Captafol.의 토양근주에 의하여 본 병원균의 토양내 균량은 크게 감소되었으며, Trichoderma sp. 의 균량은 오히려 증가되었다.

• 식물병연구
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• 제11권1호
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• pp.35-38
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• 2005

2001년에서 2003년까지 국내 딸기주산단지에서 딸기시들음병 발생실태 조사를 실시하였다. 딸기시들음병 발생은 주로 육묘기인 6월부터 8월, 정식기인 9월부터 10월, 수확기인 1월부터 3월까지 발생되었다. 병징은 뿌리가 갈변되어 크라운의 도관을 따라 갈변되었고 짝잎을 형성하였다. 시들음병 발생은 214개 포장 중 37개 포장에서 최대 30%까지 발생되었다. 딸기 시들음병은 Dochiodome, 매향, Redpearl, Samaberry, Akihime 품종 등 조사된 모든 품종에서 발생하였으나, 특히 Samaberry, 매향, Dochiodome 에서 많이 발생하였다. 시들음병 발생토양은 무발병 토양보다 전기전도도, 질소, 인산농도가 높았고, pH는 낮게 나타났다. Dochiodome 와 Samaberry 품종에서 분리된 Fo47, Fo79 균주는 공시된 4품종에 대해 병원성이 강했으며 특히 Dochiodome, Redpearl, 매향 품종은 더 감수성이었다.

• The Plant Pathology Journal
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• 제34권3호
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• pp.163-170
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• 2018

Strawberry Fusarium wilt disease, caused by Fusarium oxysporum f. sp. fragariae, is the most devastating disease in strawberry production. The pathogen produces chlamydospores which tolerate against harsh environment, fungicide and survive for decades in soil. Development of detection and quantification techniques are regarded significantly in many soilborne pathogens to prevent damage from diseases. In this study, we improved specific-quantitative primers for F. oxysporum f. sp. fragariae to reveal correlation between the pathogen density and the disease severity. Standard curve $r^2$ value of the specific-quantitative primers for qRT-PCR and meting curve were over 0.99 and $80.5^{\circ}C$, respectively. Over pathogen $10^5cfu/g$ of soil was required to cause the disease in both lab and field conditions. With the minimum density to develop the wilt disease, the pathogen affected near 60% in nursery plantation. A biological control microbe agent and soil solarization reduced the pathogen population 2-fold and 1.5-fold in soil, respectively. The developed F. oxysporum f. sp. fragariae specific qRT-PCR protocol may contribute to evaluating soil healthiness and appropriate decision making to control the disease.