• Korean Journal of Organic Agriculture
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• v.28 no.3
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• pp.417-430
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• 2020

Drought stress is one of major environmental stresses in plants; this leads to reduce plant growth and crop yield. In this study, we selected fungal isolate for mitigating drought stress in pepper plants. To do this, 41 fungi were isolated from rhizosphere or bulk soils of various plants in Jeju, Gangneung, Hampyeong in Korea. Out of 41 isolates, we screened two isolates without phytotoxicity through seed germination of tomato, pepper, and cabbage treated with fungal spores; through following plant assay, we selected GL02 as a candidate for alleviating drought stress in pepper plants. As a result of greenhouse test of pepper plants in drought condition, the stomatal conductance on leaves of pepper plants treated with GL02 was increased, whereras the malondialdehyde (MDA) and electrolyte leakage were decreased compared to that in control plants. When stressed plants were rewatered, stomatal conductance of the plants treated with GL02 was increased; the electrolyte leakage was decreased. Based on internal transcribed spacer (ITS) sequencing analysis, isolate GL02 was belonging to genus Trichoderma. Taken together, drought stress in pepper plants treated with GL02 was alleviated, when it was rewatered after drought-stressed, the plants could be recovered effectively. Therefore, Trichoderma sp. GL02 could be used as a bio-fertilizer to alleviate drought stress in pepper plants.

• The Korean Journal of Mycology
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• v.23 no.4 s.75
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• pp.318-324
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• 1995

The evolutionary relationships of the genus Trichoderma and related taxa were assessed using partial sequencing of 18S ribosomal RNA. Phylogenetic tree divided into three major groups; 1. Saccharomyces cerevisiae-Geotrichum klebahnii-Alternaria mali group; 2. Neurospora crassa-Aspergillus-Penicillium-Chrysosporium pannorum-Scopulariopsis sp. group; 3. Trichoderma group. The genus Trichoderma seemed to be phylogenetically separated from Saccharomyces cerevisiae, Aspergillus and Penicillium groups, and have passed through it's own evolutionary pathway.

• Korean Journal Plant Pathology
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• v.11 no.4
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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.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.61-83
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• 2012

To identification of fungi that occurs round bale silages, 253 fungal contaminated samples were collected from 2009 to 2011. Total 253 silage samples from Italian ryegrass, sudan grass, rye, corn, barley and oat were analysed. Total 270 strains were purely isolated from contaminated round bale silages. The fungi were identified with morphological characteristics and rDNA sequence analysis. Nineteen species of fungi(Rhizopus sp., Fusarium spp., Coprinus sp., Blastomyces sp., Aureobasidium sp., Polypaecilum sp., Botryoderma sp., Mucor sp., Scytalidium sp., Sphaeropsis sp., Aspergillus spp., Trichocladium sp., Humicola sp., Staphylotrichum sp., Periconia sp., Verticillium sp., Diplococcium sp., Penicillium spp. and Trichoderma spp.) were identified by morphological characteristics. On the other hand, fungi isolated from silage were identified to Acremonium strictum, Aspergillus tubingensis, Bionectria ochroleuca, Dipodascaceae sp., Fusarium proliferatum, Fusarium oxysporum, Fusrium solani, Gelasinospora reticulata, Gibberella moniliformis, Gibberella zeae, Nectria mauritiicola, Penicillium paneum, Pseudallecheria boydii, Schizophyllum commune, Scopulariopsis brevicaulis and Simplicillium lamellicola by rDNA sequence analysis. Penicillium sp. and Trichoderma sp., were isolated 74 and 64 strains, respectively. Humicola sp., Aspergillus sp., Coprinus sp., and Fusarium spp. were identified 10 to 30 strains. Most fungi were isolated together with more than one species in a sample looked like one species with the naked eyes.

• The Korean Journal of Mycology
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• v.36 no.1
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• pp.9-15
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• 2008

For the detection of contaminated liquid spawn, we selected suitable medium, indicator and developed method of diagnosis. The growth of pathogenic bacteria, Pseudomonas sp., and fungi, Trichoderma sp., in YPL media was better than in PDA and NA. In addition, the changes of color and absorbance of media were obviously showed when contaminated liquid spawn by pathogenic bacteria and fungi was incubated on YPL including phenol red for 48 hour at $25^{\circ}C$. The color of YPLP after incubating of infected liquid spawn by Pseudomonas sp. and Trichoderma sp. were changed from orange to red and to scarlet, respectively. Whereas, the color of YPLP after incubation of only Pleurotus ostreatus indicated yellow at liquid spawn. Therefore, it is possible to easily distinguish contaminated liquid spawn by color of change in YPLP.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.20-25
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• 2000

One of endoglucanases(F-II-II) was purified from the culture filtrate of Trichoderma sp. C-4 through two step procedures including chromatography on Sephacryl S-200 and Sephacryl S-100. The molecular weight of the enzyme was determined to be about 26,000 by SDS-PAGE and the isoelectric point as 8.0 by analytical isoelectric focusing. The optimum temperature of the enzyme was $50^{\circ}C$ and the optimum pH was 5.0. No loss of activity was observed when the enzyme was preincubated at $50^{\circ}C$ for 24 hours. The specific activity of the enzyme toward carboxymethylcellulose (CMC) was estimated to be 776.2 U/mg. The internal amino acid sequence was analysed.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.229-236
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• 2005

Molecular profIles of PCR-RFLP and sequence analysis of internal transcribed spacer (ITS) regions of rDNA were compared between morphologically distinguishable species of Trichoderma isolated from substrates of oyster mushroom in Korea, T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, T. virens, and two unidentified species, Trichoderma sp. 1 and 2. PCR­RFLP analysis divided the Trichoderma spp. into six RFLP groups, A, B, C, D, E, and F. The RFLP groups were generally agreed with described morphological species, except that the RFLP group A containing the two unidentified species. A neighbor-joining tree based on ITS sequences well supported RFLP groups observed by RFLP analysis of ITS regions of rDNA. Additionally, the two unidentified species, Trichoderma sp. 1 and 2, which could not be distinguished by PCR­RFLP analysis, were separated in sequence analysis of ITS regions of rDNA.

• Mycobiology
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• v.50 no.4
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• pp.244-253
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• 2022

Trichoderma fungi have been intensively studied for mycoparasitism, and the latter is closely related to their cell-wall degrading enzymes including chitinase. Here, we studied marine-derived Trichoderma spp., isolated from distinct sources and locations, for chitinolytic and antifungal activity. Based on morphological and phylogenetic analyses, two strains designated GJ-Sp1 and TOP-Co8 (isolated from a marine sponge and a marine alga, respectively) were identified as Trichoderma bissettii. This species has recently been identified as a closely related species to Trichoderma longibrachiatum. The extracellular crude enzymes of GJ-Sp1 and TOP-Co8 showed activities of chitobiosidase and b-N-acetylglucosaminidase (exochitinase) and chitotriosidase (endochitinase). The optimum chitinolytic activity of the crude enzymes was observed at 50 ℃, pH 5.0, 0-0.5% NaCl concentrations, and the activities were stable at temperatures ranging from 10 to 40 ℃ for 2 h. Moreover, the crude enzymes showed inhibitory activity against hyphal growth of two filamentous fungi Aspergillus flavus and Aspergillus niger. To the best of our knowledge, this is the first report of the chitinolytic and antifungal activity of T. bissettii.

• The Korean Journal of Mycology
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• v.35 no.1
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• pp.33-36
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• 2007

An attempt was made to investigate the status of harmful microorganisms occurring on different kinds of oak bed-logs during shiitake cultivation. As a result, totally 14 species of harmful microorganisms, including Trametes versicolor, were confirmed. Twelve kinds of harmful microorganisms were observed on Quercus acutissima, 9 kinds on Q. mongolica and 10 kinds on Q. aliena. Diatrype stigma, Hypoxylon truncatum, Hypoxylon sp. and Trichoderma sp. occupied 75.1% of the total harmful fungi occurred on Q. acutissima. H. truncatum and Trichoderma sp. occupied 71.2% of the total harmful fungi occurred on Q. mongolica. On Q. aliena, the occurrence of H. truncatum, Trichoderma sp. and Hypoxylon howeianum was 80.3%. D. stigma and Hypoxylon sp. were observed exclusively on Q. acutissima bed-logs, and the outbreak ratios were 51.6% and 13.1%, respectively. H. truncatum was observed on 46.6% of Q. aliena bed-logs and Trichoderma sp. was observed on 30.3% of Q. mongolica bed-logs.

• Journal of Mushroom
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• v.13 no.3
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• pp.256-261
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• 2015

This study was conducted to reduce contamination ratio of oyster mushroom bottle cultivation. The optimal conditions of substrate sterilization for reducing of contamination ratio were at $121^{\circ}C$ for 90 min. In addition, UV-C irradiation is good for lower contamination ratio to continue over 6 hours at cooling and inoculation room after sterilization. The contamination ratio and density of microorganisms of substrate were showed 0% after sterilization at $121^{\circ}C$ for 90 min. Trichoderma sp., main pathogen of mushrooms, was detected from substrate after sterilized during 2 or 4 hours at $101^{\circ}C$ and $105^{\circ}C$, respectively. The amount of electricity used was the lowest at $121^{\circ}C$ for 90 min than that of other sterilization conditions. The UV-C irradiation treatment was used UV-C lamp(40 watts) in the inoculation room($56m^3$). The density of bacteria did not detected after UV-C irradiation for 6 hours. And the death ratio of bacteria and Trichoderma sp. was 99.9% after UV-C irradiation for 6 hours. However, in the same UV-C irradiation time, the death ration of Cladosporium sp. was 90.9%. Therefore, the death ratio of fungi was lower than that of bacteria at the same UV-C irradiation treatment.