• Journal of Mushroom
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• v.9 no.3
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• pp.110-115
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• 2011

Trichoderma disease of oyster mushroom has not been effectively detected in the field for testing its resistance against the disease with its varieties. In this study, we investigated the methods to detect its resistance in the laboratory by using media, which enables us to understand the relevant characteristics (e.g., lysis, toxin enzyme, mycelial growth rate). In coculturing with strains of Trichoderma and oyster mushroom, it is possible to observe the difference in the resistance of oyster mushroom against Trichoderma with the phenomena of barrage reaction, overgrowth and lysis. We also observed the inhibition of mycelial growth of oyster mushroom using the dilution method with 48-well plate, but could not observed the inhibition of mycelial growth using the filter paper method of cultural supernatant. In simultaneously culturing both Trichoderma and oyster mushroom, it was possible to detect the inhibition of the mycelial growth of oyster mushroom, but Trichoderma mycelium did not overgrow against oyster mushroom. We found that the pathogenicity was efficient in using solid medium with the phenomena of overgrowth and lysis by inoculating Trichoderma on top of mycelia of oyster mushroom. In conclusion, the methods (e.g., coculture method, dilution method with 48-well plate, post-inoculation method) are recommended to detect the resistance of oyster mushroom against Trichoderma disease.

• Journal of Mushroom
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• v.9 no.4
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• pp.170-179
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• 2011

In coculturing with strains of Trichoderma and oyster mushroom, we could detect the difference in the resistance of oyster mushroom against Trichoderma with the phenomena of barrage reaction, overgrowth and lysis. We selected the isolates ASI 2183, ASI2504 and ASI 2477 as varieties that showed the resistance. The isolates ASI 2240, ASI 2479 and ASI 2181 were the best in their resistance against Trichoderma in the method using culture filtrate. In common, the isolates ASI 2479 and ASI 2240 were selected in both methods. In post-inoculation method, the isolates ASI 2479, ASI 2333 and ASI 2181 were selected and ASI 2302 was susceptible. For the same isolate of Trichoderma, the resistance varied depending on the isolates of oyster mushroom used in the experiments. Because we could detect the interactions between Trichoderma and oyster mushroom, it is possible to detect the level of the resistance that differs in the varieties. However, there were the cases of detecting the level of the resistance in repetitions with the same isolate, which may be caused by the vitality of isolates of Trichoderma and oyster mushroom. It is efficient to test the resistance with the resistant isolate of Pleurotus salmoneostramine and the susceptible isolate of ASI 2302.

• Korean Journal Plant Pathology
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• v.12 no.4
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• pp.395-401
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• 1996

국내의 고추, 사과, 포도, 스타티스(statice)에서 분리한 Glomerella cingulata 균주들의 병원성과 체세포화 합성군(vegetative compatibility group : VCG)과의 관계를 조사하였다. 사과, 포도, 스타티스에서 분리된 균주들은 전기주에 모드 병원성을 나타내었으나 고추에는 병원성이 없었다. 한편, 고추에서 분리된 균주들은 무상처접종시 병원성을 나타내지 못하였다. Nitrate nonutilizing(nit) mutant는 1.5%의 KClO\ulcorner을 첨가한 최소배지에서 선발하였다. nit mutnat들은 nit1, nit2, nit3, nitM의 4가지 표현형 중 하나에 속하였다. VCG는 표현형이 다른 nit mutan간의 대치배양을 통해 결정하였는데 사과, 포도, 스타티스에서 분리한 균주들간에는 같은 VCG를 나타낸 반면 고추에서 분리된 균주들은 다른 VCG로 나타났다. 따라서 G. cingulata 균주들의 체세포화합성은 병원성과 밀접하게 관련되어 있음을 알수 있었다. 또한 동일한 VCG에 속하며 기주가 다른 균주들의 대치배양시 heterokaryon을 형성했으나 자낭을 형성하지는 않았다.

• Journal of Mushroom
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• v.2 no.4
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• pp.184-191
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• 2004

Mutual growth limitation was observation when the two antagonistic fungi was come in contact with each other. Brown line was formed 2day after contact with Trichoderma spp., and then, green spores formed overnight. The laccase activity of L. edodes was stimulated when this fungus wsa co-incubated with Trichoderma spp. for a few days in liquid media. In sawdust-rice bran nixtures, outstanding broun line developed when the two antagonistic fungi co-cultured. The pH of the substrates changed from 5.5 to 4.5 after overgrowth, suggesting a difference in the degradation ability and the preference of the two fungi for the lignocellulose material.

• Horticultural Science & Technology
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• v.18 no.6
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• pp.802-807
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• 2000

This study was conducted to propagate the arbuscular mycorrhizal fungi in vitro using the hairy root of carrot transformed by Agrobacterium rhizogenes with Ri t-DNA. Mycorrhizal spores and roots in sudangrass plants were wet-sieved, surface-sterilized and inoculated onto the hairy root of carrot on the Modified Strullu & Romand (MSR) medium. The mycorrhizal spores of Glomus sp. propagated in vitro for 12 weeks was about $50{\mu}m$, and the shapes of spores were round or elliptic. Spores were formed mainly at the middle of the hyphae. Number of mycorrhizal spores propagated using dual culture of the transformed carrot roots and the mycorrhizal inoculum for 12 weeks were about 1,200 per plates.

• The Korean Journal of Pesticide Science
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• v.9 no.1
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• pp.102-107
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• 2005

To select microorganisms that exhibit antifungal activity against the fungal pathogens of pepper, Phytophthora capsici and Colletotrichum acutatum, soil samples from a forest and natural fields of Gajang-Dong, Sangju-city were tested in vitro and in vivo. Streptomyces griseofuscus 200401 was finally selected throughout antifungal activity test with dual culture, culture broth, and fruits. For the identification of the strain, nucleotide sequences of 16S rDNA and whole cell fatty acids were analyzed. It is like that the strain 200401 may be a novel biological control agent that can reduce application of chemical fungicides to control late blight and anthracnose on pepper.

• The Korean Journal of Mycology
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• v.39 no.1
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• pp.44-47
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• 2011

A harmful fungus occurred seriously in bed-log of shiitake(Lentinula edodes) in Jangheung-Gun, Korea. The fungus was identified as Bjerkandera adusta by its morphology and ITS(Internal Transcribed Spacer) analysis. The fungus was reported as causal agent of stem-rot of Populus euramericana in Korea, but not reported in bed-log of shiitake until this notification. Thus, studies were made to investigate inside condition of bed-log of shiitake damaged by B. adusta, physiological characteristics of B. adusta and antagonism between these two fungi. First of all, B. adusta is white-rotting fungus like shiitake and wood-rotting condition is similar to that of shiitake. But, there are a lot of small spots in damaged wood tissue under bark which are not seen in case of shiitake. Optimal temperature for mycelial growth of B. adusta is ca. $30^{\circ}C$ while that of shiitake is ca. $25^{\circ}C$. When confrontation cultures were made between these two fungi under $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ and $30^{\circ}C$, B. adusta has antagonistic ability against shiitake in all the temperatures. From the results of experiments, if the bed-logs of shiitake are exposed to high temperature, there should be mass propagation of B. adusta, and shiitake mycelia will be seriously injured by the fungus. Therefore, to prevent the damage by B. adusta, it is needed to grow the mycelia of shiitake fast in the bed-log, and to avoid exposure of the bed-log to high temperature in summer.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.657-665
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• 2013

A large patch disease caused by Rhizoctonia solani AG2-2 (IV) is a serious problem in Korean lawngrass (Zoysia japonica) sites including golf courses and sports fields in Korea. Antagonistic microorganisms against R. solani AG2-2 (IV) were isolated from various forest and crop soil sources in Southern Korea. Among the 61 isolates, I-009, FRIN-001-1, and YPIN-022 strains showing dramatic inhibition of the mycelial growth of R. solani AG2-2 (IV) in the pairing culture were selected as the most potential antagonistic microorganisms for this study. Based on the 16s RNA sequence comparison, I-009 and FRIN-001-1 isolates were identified as Bacillus spp., while YPIN-022 isolate belongs to the genus Pseudomonas. The greater inhibition (clear) zone between two edges of the selected and pathogenic microbes ranged from 11 to 15 mm in three selections, but the others averaged to 7 mm out of 30 mm distance. In another antifungal test using culture filtrate, those three isolates represented a range of 51.7 to 63.5% suppression potential. The selected isolates also inhibited significantly the stem-segment colonization by R. solani AG2-2 (IV) in vivo test by 28.1%, 43.0%, and 23.7% when inoculated with I-009, FRIN-001-1, and YPIN-022, respectively. The highest antagonistic activity for the large patch disease was demonstrated by the isolate FRIN-001-1, which will be useful for developing a bio-pesticide against Rhizoctonia.

• Journal of Mushroom
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• v.12 no.1
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• pp.41-51
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• 2014

Cauliflower mushroom widely known high concent of ${\beta}$-glucan for farm cultivation invigoration verified characteristics of mycelia growth, genetic diversity, resistance to Trichoderma by replacement culture with Trichoderma and growth characteristics of new variety crossbleeding strain. The result of replacement culture with Trichoderma for verification resistance about Trichoderma, 6951 (T. viride) strain did not show special change after formation of confrontation line and 6952 (T. spp.) strain was showed more formation of spore after formation of confrontation line. But 6426 (T. harzianum) strain found to encroach part of growth area of cauliflower mushroom mycelia. Among 10 kinds cauliflower mushroom strain, JF02-06 strain collected by Gurye, found did not spore of Trichoderma and thought to be resistant to Trichoderma. The result of crossbleeding after selected that mother strain good growth and formation of fruit body, verified good mycelia growth at JF02-47, 49 and 50 strain in Korean pine of wood-chip media. The result of gene sequence about ITS1, 5.8S and ITS4 for analysis of genetic diversity at crossbleeding strain, found high significance to other cauliflower mushroom in registered Genebank. The result of growth characteristic of spore and mycelia of cauliflower mushroom by observation microscope, size of spore showed water drop shape to major axis $6{\mu}m$ and minor axis $5{\mu}m$ and clamp showed 3 types in mycelia. The wide of mycelia was $3{\mu}m$. The characteristic of mycelia of cauliflower mushroom found to grow mycelia in clamp at approximately 50%. The growth speed of mycelia was $0.507{\mu}m/min$ and 2nd mycelia grown similar speed to mother mycelia at parallel with mother mycelia after growth speed at $0.082{\mu}m/min$. The formation of clamp made small clamp for 5 hours after shown transfer of electrolyte in mycelia inside. The septum formation started after 3 hours and then finally completed after 2 hours. In this study, strain of cauliflower mushroom verified resistance of Trichoderma, genetic diversity and characteristic of mycelia growth. Therefore, basic knowledge of cauliflower mushroom will improve and further contribute to development of mushroom industry.

• Korean Journal of Organic Agriculture
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• v.29 no.4
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• pp.575-588
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• 2021

The purpose of this study is to select actinomycetes with antifungal activity against Botrytis cinerea and Colletotrichum orbiculare, which are airborne pathogens in cucumber plants. In 2020, 560 species of actinomycetes were isolated from rhizome soils of various vegetables in Korea; 7 strains showing simultaneous antifungal activity against two pathogens were selected. Finally, strain S20-465 was selected through dual culture and plant assay. This strain was identified as Streptomyces sp. based on 16S rRNA analysis. The culture filtrate of strain S20-465 inhibited mycelial growth of both pathogens by more than 60%. In addition, when cucumber plants were treated with 20-fold and 40-fold diluted culture filtrates of S20-465, lesions caused by B. cinerea and C. orbiculare on cucumber leaves were significantly reduced compared to the control. This results suggest that strain S20-465 produces specific secondary metabolites with antifungal activity against both pathogens.