• 한국식물병리학회지
• /
• 제10권4호
• /
• pp.319-324
• /
• 1994

The monoxenic culture of the fungivorous nematode, Aphelenchus avenae, was applied for the control of soil-borne ginseng pathogens such as Fusarium solani and Rhizoctonia solani. Fungivorous nematode populations were measured in a field to examine relationships between the nematode populations and suppression of ginseng root diseases. Inoculation of A. avenae (5000 nematodes per petri-dish) reduced the colonization of the Fusarium mycelium on root discs of ginseng and carrot by 80.0% and 60.5%, respectively. A. avenae also significantly reduced the occurrence of damping-off of ginseng by R. solani pathogenic to ginseng, and no plant damage by the nematode was noted. In a 3-year-old ginseng field infested with Cylindrocarpon destructans, plant missing caused by root rot positively correlated to the density of potato rot nematode, Ditylenchus destructor, but it was reduced with the population of A. avenae, suggesting that A. avenae might inhibit the occurrence of ginseng root rot.

• 한국미생물·생명공학회지
• /
• 제41권1호
• /
• pp.70-78
• /
• 2013

Rhizoctonia solani and Fusarium oxysporum cause yield losses in numerous economically important crops. To develop a bio-control agent, cell free extracellular compounds (ECs) of 5 bacterial strains Burkholdria sp. L1, Pseudomonas sp. L4, Pseudomonas chlororaphis VN391, Bacillus subtilis VN21 and Enterobacter sp. VN99 from Vietnamese fields, which reduced levels of R. solani root rot in lettuces and F. oxysporum root rot in tomatoes, were investigated. In a growth chamber, ECs of all antagonists markedly enhanced the biomass of lettuces (10 to 14.1%) and tomatoes (11.38 to 13.88%). In greenhouses, the disease's severity on both crops treated with ECs of the antagonists was reduced significantly and biomass losses in the plants decreased markedly. The reduction level of R. solani root rot in lettuces was 75, 66.7, 50, and 16.7% by ECs of strains L1, L4, VN21 and VN391, respectively. The biomass of lettuces increased markedly by 29.13%, 21.67%, and 23.4% by ECs of strains L1, L4 and VN21, respectively. Similarly, the reduction levels of F. oxysporum root rot in tomatoes was 76.3, 75, 41.7 and 25% by ECs of strain L1, L4, VN21 and VN391, respectively, and the biomass was significantly enhanced by 14.42, 12.7 and 13%, respectively. The ECs of strain L1 exhibited the most effective bio-control agents to suppress R. solani and F. oxysporum.

• Journal of Microbiology and Biotechnology
• /
• 제10권4호
• /
• pp.435-440
• /
• 2000

A pathogenic fungus causing balloon flower root rot (Platycodon grandiflorum) was isolated from naturally infected roots. The microbial characteristics of the isolated microorganism were similar to those of Rhizoctonia solani. About 500 bacterial species from field soils were screened for a biological agent against the above-mentioned putative pathogen, and several bacteria with the antifungal activity were isolated. Among them, the isolated JS2 was identified as Pseudomonas aeruginosa. This strain showed a broad spectrum of antifungal activity potentially. When the antifungal substance was purified from a broth culture of JS2, it was identified as 2,4-diacetylphloroglucinol (Phl).

• Mycobiology
• /
• 제41권1호
• /
• pp.47-55
• /
• 2013

Rhizoctonia solani, Fusarium solani, F. oxysporum, and Macrophomina phaseolina were found to be associated with root rott and wilt symptoms of faba bean plants collected from different fieldes in New Valley governorate, Egypt. All the obtained isolates were able to attack faba bean plants (cv. Giza 40) causing damping-off and root rot/wilt diseases. R. solani isolates 2 and 5, F. solani isolate 8, F. oxysporum isolate 12 and M. phaseolina isolate 14 were the more virulent ones in the pathogenicity tests. Biocontrol agents (Trichoderma viride and Bacillus megaterium) and chemical inducers (salicylic acid [SA] and hydrogen peroxide) individually or in combination were examined for biological control of damping-off and root rot/wilt and growth promoting of faba bean plants in vitro and in vivo. Both antagonistic biocontrol agents and chemical inducers either individually or in combination inhibited growth of the tested pathogenic fungi. Biocontrol agents combined with chemical inducers recorded the highest inhibited growth especially in case SA + T. viride and SA + B. megaterium. Under green house and field conditions, all treatments significantly reduced damping-off and root rot/wilt severity and increased of survival plants. Also, these treatments increased fresh and weights of the survival plants in pots compared with control. The combination between biocontrol agents and chemical inducers were more effective than used of them individually and SA + T. viride was the best treatment in this respect. Also, under field conditions, all these treatments significantly increased growth parameters (plant height and number of branches per plant) and yield components (number of pods per plant and number of seeds per plant, weight of 100 seeds and total yield per feddan) and protein content in both seasons (2010~2011 and 2011~2012). Faba bean seeds soaked in SA + T. viride and SA + B. megaterium were recorded the highest growth parameters and yield components. Generally, the combination between biocontrol agents and chemical inducers recorded the best results for controlling damping-off and root rot/wilt diseases in greenhouse and field with addition improved plant growth and increased yield components in field.

• 식물병연구
• /
• 제7권1호
• /
• pp.11-15
• /
• 2001

최근 박과류 재배 주산단지에서 발생이 증가하고 있는 검은점뿌리썩음병의 방제에 필요한 기초자료를 얻기 위해서 지역적인 발생분포와 발생소장을 조사하고 병원성을 검정하였다. Monosporascus cannonballus 에 의한 검은점뿌리썩음병은 멜론, 참외, 수박 및 오이에서 발생하였으며, 발생포장 수는 \\`97년 10개 포장에서 \\`98년 32개 포장으로 확대되었고, 발생지역은 김해, 진주, 남해, 광양, 광주, 여주, 이천 등이었다. 경남 남해 멜론 재배포장에서 발생소장을 조사한 결과, 생육중기까지는 발병을 관찰할 수 없었으나, 과실 성숙기에 급격히 발병이 증가하여 50%이상의 식물체 덩굴이 시들어 고사하였다. 시들은 증상을 나타내는 기주에서 M. cannonballus의 분리비율은 36.7%이었고, Fusarium oxysporum과 Rhizoctonia solani도 높은 비율로 분리되었다. 물한천 시험관법에 의한 박과류 유묘에 대한 병원성은 접종후 7∼14일 사이에 대부분의 식물체가 시들고 21일후에는 뿌리에 자낭각이 형성되었다. 특히 오이품종 중에서 백봉과 은화는 저항성 반응을 나타내었다.

• The Plant Pathology Journal
• /
• 제30권4호
• /
• pp.432-436
• /
• 2014

The soil-borne ascomycete fungus Cylindrocarpon destructans causes ginseng root rot disease and produces various secondary metabolites such as brefeldin A and radicicol. The slow growth of this fungus compared with other plant pathogenic and saprophytic fungi in soil disturbs isolation of this fungus from soil and infected ginseng. In this study, we developed a selective medium for C. destructans using radicicol produced by this fungus. Supplementing 50 mg/L of radicicol to medium inhibited the mycelia growth of other fungi including Botrytis cinerea, Rhizoctonia solani and Alternaria panax, but did not affect the growth of C. destructans. In addition, conidia germination of other fungal species except for C. destructans was inhibited in submerged culture supplemented with radicicol. This medium provides a very efficient tool for isolating C. destructans and also can be used as an enrichment medium for this fungus.

• 한국식물병리학회지
• /
• 제10권2호
• /
• pp.112-118
• /
• 1994

Forth microbial isolates out of 167 isolates from the soil of controlled cultivation areas inhibited mycelial growth of Rhizoctonia solani AG2-1 causing the strawberry bud rot in vitro. Among the isolates, Kr013 and Kr020 showed suppressive effect to R. solani AG2-1 on seedlings of chinese cabbage treated by root immersion, charcoal carrier granule and drenching on 1.0% infested soil in pot. Furthemore, the corresponding effect was also revealed when the charcoal carrier granule of the isolates were treated on the seedling of strawberry that were planted on the planting hole in pot. To examine the effects of biological control in green house, it had been tested the infection rates by using two different treatments. First, the strawberry runner were planted on the nursery soil mixed with 20% charcoal carrier granule of Kr013 and Kr020 isolate respectively, and grown for 20 days before transplanting. Then the young plants form the mother plant were separated and transplanted on the 1.0% infested soil. Another method was that the charcoal carrier of Kr013 and Kr020 isolates applied to planting hole of 1.0% infested soil just before transplanting. Then the young plants were grown for 20 days on the sterilized nursery soil before transplanting. From the results, the effects of biological control was significantly higher on former treatment (e.g. the infection rates were 7.3 and 5.7%, respectively) than on the latter treatment (e.g. the corresponding value were 16.7 and 15.7%, respectively). The antagonistic isolates of Kr013 and Kr020 were respectively identified as Pseudomonas cepacia with the similarity of 55.0% and 60.0% by using the Biolog GN Microplate system.

• 한국응용곤충학회지
• /
• 제25권3호
• /
• pp.183-189
• /
• 1986

강원도 고냉지 배추재배 지역에서 53개의 이병 뿌리와 22개 토양 표본을 채취하여 배추 생육 초기에 뿌리 썩음을 일으키는 병원균을 조사하였다. 이병된 뿌리에서 검출된 13개 곰팡이 중에서 Pythium ultimum, Pythium echinocarpum, Rhizoctonia solani의 3종이 자주 검출 되었으며 배추에 병원성이 있었다. 채취한 토양에 본엽 $3{\sim}4$ 엽기의 배추를 이식하여 발명 유무를 온실에서 조사 하였을 때 토양 표본에 따라 5내지 100%의 식물이 이들 균에 의하여 감염 되었다. 토양내 이들 3종의 균의 밀도를 배추 식물의 감염 빈도에 의하여 조사 하였을 때 차항 2리 지역의 토양에서는 P. ultimum이 우점종 이었고 P. echinocarpum은 용산 2리, 횡계리, 문맥 지역에서 주로 밀도가 높았다. 매봉산 지역의 토양에서는 R. solani 균만이 단지 분포하고 있었으며 P. ultimum 과 P. echinocarpum이 동시 분포하는 지역에서는 대체로 P. echinocarpum 균의 밀도가 P. ultimum에 비하여 더 높았다. 주요 30품종의 유묘를 가지고 온실에서 품종 저항성을 조사한 결과 6개 품종이 P. ultimum 에 대하여 저항성이었고 3개 품종이 중도 저항성 이었다. P. echinocarpum에 대해서는 저항성 품종이 없고 2개 품종이 중도 저항성 이었으며 R. solani균에 대해서는 모두가 이병성 이었다.

• 한국응용곤충학회지
• /
• 제19권4호
• /
• pp.228-233
• /
• 1980

The infection rate of soybean black root rot disease caused by Calonectria crotalariae was about $14\%$. The isolated fungi from the infected soybean roots and stems were Calonectria crotalariae, Fusarium solani, F. roseum, Phomopsis sojae, Pythium aphanidermatum, Rhizoctonia solani and Macrophomina sp. Among them, C. crotalariae was the most virulent pathogen under the laboratory conditions. Mycelial growth and microsclerotial formation were good on PSA containing 1000cc of water, 100g of potato and 20g of sugar. Mycelial growth, sporulation and microsclerotial formation were good on sterilized root. Perithecial formation was better in the dark condition than in the light. Survival of macroconidia was not available between $0\~25\%$ soil water content. Microsclerotia and mycelium in infected plant debris were survived for 4 months at to $8\%\;50\%$ soil water content. The plant height, when inoculated with $1.2\%$ inoculum density, reached approximately half of uninoculated plants. Disease severity was much higher at nonsterilized soil than completely sterilized soil. It was determined that the host range of this pathogen includes soybean, peanut, green bean and red bean.

• 한국응용곤충학회지
• /
• 제23권3호
• /
• pp.142-146
• /
• 1984

인삼 근부병 억제토양 및 유발토양의 추출액 배지에서 병원균인 Fusarium solani, Rhizoctonia solani, Phytophthora cactorum, Sclerotinia sp.의 균계생장과 여기에 영향을 미지는 두 토양의 근권환경을 비교하였다. 4병원균 모두 추출액을 열처리하지 않았을 때 유발토양보다 억제토양 추출액 배지에서 생장이 더 억제되였고, $100^{\circ}C$로 처리 하였을 때는 F. solani와 Sclerotinia sp.는 두 토양간에 차이가 없었으나 R. solani와 P. cactorum은 유발토양에서 균사생장이 더 좋았다. 또 억제토양 추출액의 열처리 온도를 높힐수록 모든 병원균의 생장이 증가되었다. 두 토양의 근권미생물 밀도는 Fusariumtn는 유의차가 없었으나 전세균, 진균은 모두 억제토양에 밀도가 더 높았으며 이 미생물들에 대한 Fusarium밀도의 비율도 억제토양이 더 높았다. 점토함량은 액제토양이, 모래함량은 유발토양이 각각 더 높았고, 화학성분중 Mg, Na 함량은 유발 토양이 더 많았으며 Ca, Fe, $P_2O_5$도 유의성은 없었으나 억제토양 보다 높은 경향이었다.