• Journal of Microbiology and Biotechnology
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• 제27권6호
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• pp.1157-1162
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• 2017

The goal of this study was to identify and characterize selected Trichoderma isolates by metabolic profiling and enzyme assay for evaluation of their potential as biocontrol agents against plant pathogens. Trichoderma isolates were obtained from the Rural Development Administration Genebank Information Center (Wanju, Republic of Korea). Eleven Trichoderma isolates were re-identified using ribosomal DNA internal transcribed spacer (ITS) regions. ITS sequence results showed new identification of Trichoderma isolates. In addition, metabolic profiling of the ethyl acetate extracts of the liquid cultures of five Trichoderma isolates that showed the best anti-Phytophthora activities was conducted using gas chromatography-mass spectrometry. Metabolic profiling revealed that Trichoderma isolates shared common metabolites with well-known antifungal activities. Enzyme assays indicated strong cell wall-degrading enzyme activities of Trichoderma isolates. Overall, our results indicated that the selected Trichoderma isolates have great potential for use as biocontrol agents against plant pathogens.

• Journal of Microbiology and Biotechnology
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• 제20권9호
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• pp.1266-1275
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• 2010

Isozyme and protein electrophoresis data from mycelial extracts of 27 isolates of Trichoderma harzianum, 10 isolates of T. aureoviride, and 10 isolates of T. longibrachiatum from Southern Peninsular Malaysia were investigated. The eight enzyme and a single protein pattern systems were analyzed. Three isozyme and total protein patterns were shown to be useful for the detection of three Trichoderma species. The isozyme and protein data were analyzed using the Nei and Li Dice similarity coefficient for pairwise comparison between individual isolates, species isolate group, and for generating a distance matrix. The UPGMA cluster analysis showed a higher degree of relationship between T. harzianum and T. aureoviride than to T. longibrachiatum. These results suggested that the T. harzianum isolates had high levels of genetic variation compared with the other isolates of Trichoderma species.

• Mycobiology
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• 제31권2호
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• pp.74-80
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• 2003

Isolates of Trichoderma spp. collected from Pleurotus ostreatus and P. eryngii beds, which included loosened substrate compactness and development of green colour, were grouped into three species. The occurrence of different species of Trichoderma was as T. cf. virens(70.8%), T. longibrachiatum(16.7%) and T. harzianum(12.5%). The conidia of Trichoderma spp. were ellipsoidal, obovoid and phialides were bowling pins, lageniform and the length of phialides was $3.5{\sim}10.0{\times}1.3{\sim}3.3{\mu}m$. Phialides of T. cf. virens and T. harzianum were tending clustered, but it was solitary disposition in T. longibrachiatum. T. cf. virens was characterized by predominantly effuse conidiation, sparingly branched, and fertile to the apex and it was penicillate type. RAPD analysis could detect variability amongst three different species of Trichoderma using two newly designed URP-primers. However, intra-specific variation could not be detected in all the isolates except for rDNA sequence data classified Trichoderma isolates into three distinct groups representing three species. The profiles of rDNA sequences of isolates representing a species showed high similarity in T. cf. virens and T. harzianum. However, there was a variation in rDNA sequences of isolates representing T. longibrachiatum. The results of present study reveals that molecular techniques of RAPD and rDNA sequencing can greatly aid in classification based on morphology and precise identification of fast evolving species of Trichoderma.

• Mycobiology
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• 제36권4호
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• pp.266-269
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• 2008

Twenty isolates of Bacillus species obtained from livestock manure composts and cotton-waste composts were tested for their antagonistic effects in vitro against three green mold pathogens of mushrooms (Trichoderma harzianum, T. koningii, and T. viridescens). However, there exists a possibility Bacillus species may have antagonistic effects against mushrooms themselves, and thus the same 20 isolates were tested in vitro against three species of mushrooms (Flammulina velutipes, Lentinus edodes, and Pleurotus ostreatus). Of the 20 Bacillus species isolates tested, two inhibited mycelial growth of T. harzianum, seven that of T. koningii, and eight that of T. viridescens. Importantly, the bacterial isolates M27 and RM29 strongly inhibited mycelial growth of all the Trichoderma spp. isolates tested. The isolate M27 was subsequently identified as the most effective in inhibiting mycelial growth of all the Trichoderma species. Interesting results of the effect Bacillus isolates had upon the mushroom species followed. It was found that most Bacillus isolates except 5T33 at least somewhat inhibited mycelial growth of the three mushroom species or some of the mushrooms. Furhermore, the antagonistic effects of the bacterial isolates against the three species of mushrooms varied depending on the mushroom species, suggesting a role for mushroom type in the mechanism of inhibition. The bacterial isolates M27 and RM29 were identified as having the most antagonistic activity, inhibiting mycelial growth of all the Trichoderma spp. as well as mycelial growth of the three species of mushrooms. These results suggest that the bacterial isolates and their antagonistic effects on green mold pathogens should be further studied for their practical use for biological control of green mold in the growing room of the mushrooms.

• 한국작물학회지
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• 제56권1호
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• pp.35-43
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• 2011

Thirty five isolates of Trichoderma species collected from seven different locations of Bangladesh were studied for morphological characters and molecular variation. Mycelial diameters of the isolates varied from 8.28 cm to 9.00 cm. Based on colony colour, isolates were grouped into five such as dark green, green, light green, yellowish green and whitish green. Maximum isolates were green and light green. On the basis of growth habit and colony consistency, the isolates were categorized into three groups, in which most species had fast growth and were compact in appearance. PCR-based Random Amplified Polymorphic DNA (RAPD) technique employing 3 decamer primers produced 36 scorable bands of which all (100%) were polymorphic. The co-efficient of gene differentiation (Gst) was 1.0000 reflecting the existence of high level of genetic diversity among the isolates. The Unweighted Pair Group Method of Arithmetic Means (UPGMA) dendrogram constructed from Nei's (1972) genetic distance produced 2 main clusters (13 isolates in cluster 1 and 22 isolates in cluster 2). The result indicating their genetic diversity has opened new possibility of using the most efficient and more isolates of Trichoderma in the preparation of biopesticide and decomposition of municipality waste.

• 한국응용곤충학회지
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• 제23권2호
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• pp.102-108
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• 1984

1. 본 연구는 Trichoderma 종간 형태적 분류와 전기영동법을 이용한 가능성에 관하여 연구하였다. 2. 전기영동법을 이용한 Trichoderma의 enzyme patterms에서 각 종의 특징적 band를 갖고 있어 종의 분류에 가능성을 보였으며 개체간 band 형성에 차이가 있는 것은 유전학적 변이가 종내 존재하며 전기영동법을 종내 유전학 연구에 도움이 되리라 간주된다. 3. Trichoderma spp.의 분류는 esterase, protein patterns으로 명확하게 6종간 구별되며 phosphotase, catalase patterns으로는 6종간 부분적 구분이 되었다.

• The Plant Pathology Journal
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• 제21권3호
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• pp.221-228
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• 2005

A total of 179 isolates of Trichoderma spp. were collected from oyster mushroom substrates in Korea. On the basis of morphological and cultural characteristics, Trichoderma isolates were divided into seven groups, namely T. atroviride, T. citrinoviride, T. harzianum, T. longibrachiatum, T. virens, and two unidentified species, referred to as Trichoderma sp. 1 and 2. The predominant species was Trichoderma sp. 2 (n=86) followed by Trichoderma sp. 1 (n=52). Trichoderma sp. 1 and 2 were morphologically distinct not only from the other species of Trichoderma reported but also from each other in the characteristics such as mycelial growth rate, colony appearance, shape of conidia and conidiophores and branching pattern of phialides, although branching pattern of phialides of Trichoderma sp. 1 was similar to that of T. harzianum. In virulence test, the degree for compost colonization of Trichoderma sp. 2 was significantly greater than that of the other Trichoderma species. Trichoderma sp. 2 was found to be the main cause of green mold disease in oyster mushroom production. More work including molecular characterization is needed to confirm the species of Trichoderma sp. 1 and 2.

• Mycobiology
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• 제38권4호
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• pp.310-315
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• 2010

Agrocybe aegerita is an important mushroom cultivated in Korea, with good feel and a peculiar fragrance. A. aegerita can be cultivated throughout the year using culture bottles but is more susceptible to contamination than other mushrooms. Twenty-two pathogens were isolated from the fruiting bodies and compost of A. aegerita, and seven isolates were isolated from Pleurotus ostreatus to compare with the A. aegerita isolates, collected from Gimje, Iksan, Gunsan of Chonbuk, and Chilgok of Gyeongbuk Province in 2009. These isolates were identified based on morphological and molecular characteristics. Of the 29 isolates, 26 were identified as Trichoderma spp. and the remaining three were Aspergillus spp., Mucor spp., and Penicillium spp. A phylogenetic analysis revealed that the 26 isolates of Trichoderma were divided into four taxa, namely T. harzianum, T. pleuroticola, T. longibrachiatum, and T. atroviride. Among the Trichoderma spp., 16 isolates (55.2%) were identified as T. harzianum, six as T. pleuroticola (20.7%), two as T. longibrachiatum, and the remaining two were T. atroviride.

• The Plant Pathology Journal
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• 제35권6호
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• pp.674-683
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• 2019

Some species of the Trichoderma genus are reported as the major problem in oak wood mushroom production in Korea. In spite of economic loss by the fungi, scientific information on airborne Trichoderma species is not much available. To generate information for disease management development we analyzed airborne Trichoderma. A total of 1,063 fungal isolates were purely obtained from indoor air sampling of cultivation houses used for oak wood mushroom using sawdust media. Among the obtained isolates, 248 isolates were identified as Trichoderma fungi including T. harzianum, T. atroviride, T. citrinoviride, and T. pseudokoningii, by morphological and molecular analysis. T. harzianum was dominant among the four identified species. All the four Trichoderma species grew fast on solid nutrient media tested (potato dextrose agar [PDA], malt extract agar [MEA], Czapek's Dox + yeast extract agar [CYA] and cornmeal dextrose agar). Compact mycelia growth and mass spore production were better on PDA and CYA. In addition, T. harzianum and T. citrinoviride formed greenish and yellowish mycelium and spores on PDA and CYA. Greenish and yellowish pigment was saturated into PDA only by T. pseudokoningii. These four Trichoderma species could produce extracellular enzymes of sawdust substrate degradation such as β-glucosidase, avicelase, CM-cellulase, amylase, pectinase, xylanase, and protease. Their mycelia inhibited the growth of oak wood mushroom mycelia of two tested cultivars on dual culture assay. Among of eleven antifungal agents tested, benomyl was the best to inhibit the growth of the four Trichoderma species. Our results demonstrate that the airborne Trichoderma fungi need to be properly managed in the cultivation houses for safe mushroom production.

• 한국버섯학회지
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• 제9권4호
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• pp.170-179
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• 2011

품종 저항성 조사방법별로병원균과 버섯품종을 다르게 하여 품종간의 차이점이 있는지를 검토하였다. 푸른곰팡이 균과 품종별 대치배양시험에서 대치라인 형성, over growth, Lysis 증상이 나타났으며, 공시품종 중에 ASI 2183, ASI2504, ASI 2477 균주가 병저항성이 있을 것으로 판단되었다. 배양여액을 이용한 방법에서는 ASI 2240, ASI 2479, ASI 2181들이 저항성을 나타냈으며, 대치배양에서는 다른 경향을 보이는 경우도 있었으나, ASI 2479, ASI 2240 균주는 대치배양, 배양여액 시험결과에서 모두 저항성을 보였다. 배양후 접종법에서는 저항성을 보이는 버섯균주는 ASI 2479, ASI 2333, ASI 2181 등이었으며, 가장 감수성 품종은 큰느타리버섯인 ASI 2302 균주로 나타났다. 푸른곰팡이균주 같은 균주에서도 품종에 따라 각기 다른 특성을 나타냈으며, 동일품종에서 푸른곰팡이균주에 따라 각기 다른 병원성을 나타냈다. 느타리버섯과 푸른곰팡이균의 상호관계에서 다양한 증상이 발생하며 느타리버섯 품종에 대한 저항성 유무를 판단할 수 있다고 판단된다. 하지만 처리량이 많은 경우 동일 처리 내의 반복처리에서도 병징의 차이가 발생하는 경우가 있으며, 이는 시험에 사용한 버섯균과 병원균의 접종원의 활력의 차이에 의해 발생하는 것으로 추정되므로 주의해야하며, 저항성 균주로는 붉은느타리종, 감수성균으로 ASI 2302 균을 대조균으로 적용하면 효과적으로 저항성 검정을 수행할 수 있을 것으로 판단된다.