• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.395-402
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• 2018

The efficacy of formulated Trichoderma harzianum-based Tricho-compost, seed treatment with Tricho-inocula, and chemical fungicide Provax 200 WP against foot and root rot diseases of wheat caused by Sclerotium rolfsii was tested in the pot house and in the research field of Plant Pathology Division, Bangladesh Agricultural Research Institute, Gazipur, Bangladesh. Tricho-compost was prepared with a mixed substrate of cow dung, rice bran, and poultry refuse colonized by T. harzianum. Seedling mortality of wheat was significantly reduced by the Tricho-compost, Tricho-inocula, and Provax 200 WP both in the pot house as well as in the field experiments. The yield of wheat was sharply increased over the control due to the T. harzianum formulations and Provax 200 WP. Among the treatments, soil application of Tricho-compost was more efficient in reducing seedling mortality and accelerating plant growth with an increased yield of wheat with S. rolfsii-inoculated pot cultures and field experiments.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.271-276
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• 2004

To examine the control effect of damping-off on radish caused by Pythium spp., researchers used the isolates of a fungivorous nematode, Aphelenchus avenae, and antagonistic fungi, Trichoderma spp. These were used as biocontrol agents, either alone, or in combination. Growth rates of the A. avenae isolates and fungal damages by the nematodes varied depending on Trichoderma spp., which contained lower T. koningii and T. virens cultures than other Trichoderma cultures. Phythium spp. were damaged by all five Aphelenchus isolates, but the multiplication rate of nematode isolate Aa-3 was very poor. Antibiotic activity of T. virens and T. harzianum to Pythium spp. was stronger than that of T. koningii. Control efficacy against damping-off of radish was most enhanced under the treatment using the nematode-T. harzianum combination. On the contrary, the combinations of the nematodes and T. virens or T. koningii mostly did not increase or decreased their control effect vis-$\`{a}$-vis that of the nematodes or antagonistic fungi being used alone. The results suggest that the fungivorous nematodes may play a leading role in the disease control, and that the activity of the fungivorous nematodes may be activated by T. harzianum, but inhibited by T. koningii and T.virens.

• Mycobiology
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• v.31 no.3
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• pp.139-144
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• 2003

This study was conducted to investigate physiological characteristics of Trichoderma spp. isolated from Pleurotus spp. Damage tests of Pleurotus spp. and mycotoxins tests of Trichoderma spp. were also done. The optimal growth temperature of Trichoderma spp. was $27{\sim}30^{\circ}C$. Although, T. longibrachiatum was able to grow at $37^{\circ}C$ and grew $30{\sim}40$ times faster than Pleurotus. The colony colour on PDA medium of T. cf. virens was yellowish green, T. longibrachiatum was yellow, and T. harzianum was turning to bright green. In damage tests of Pleurotus by Trichoderma, T. cf. virens caused the most severe damage to Pleurotus. T. longibrachiatum and T. harzianum caused less damage on Pleurotus but were able to cause greater damage to P. eryngii. One of the mushroom cultivars, P. ostreatus 8 was the most resistant to all Trichoderma spp.. Chitinolytic mycotoxin released by Trichoderma spp. caused 52.7% damage to Pleurotus. Mycotoxins released by T. longibrachiatum caused the greatest damaged(78.6%) on P. eryngii.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.69-73
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• 2018

Oak mushroom (Lentinus edodes) is cultivated by using oak logs and sawdust medium. Green mold (Trichoderma) infection on these media severely suppresses the growth of oak mushroom. Usages of antibiotics and chemicals are not generally allowed to control of green mold since the mushroom is a fresh food. Tolaasin and its analogues, peptide toxins secreted by Pseudomonas tolaasii, have the antifungal activity and they have been successful to control the green mold disease. When the green mold, Trichoderma harzianum H1, was cultured in the presence of these toxins, the growth of fungus was effectively suppressed. In sawdust media, when the bacterial culture supernatants were sprayed on the aerial hyphae of green molds, the fungal growth was completely suppressed. Particularly, the antifungal activity was greatly increased by the combined culture extracts of P. tolaasii 6264 and HK11 strains. Therefore, these bacterial strains and their peptide toxins were able to suppress the growth of green molds and these can be good candidates to prevent from Trichoderma disease in oak mushroom cultivation.

• The Plant Pathology Journal
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• v.32 no.2
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• pp.145-156
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• 2016

Fusarium graminearum Schwabe causes Fusarium head blight (FHB), a devastating disease that leads to extensive yield and quality loss of wheat and other cereal crops. Twelve isolates of F. graminearum were collected from naturally infected spikes of wheat from Assiut Egypt. These isolates were compared using SRAP. The results indicated distinct genetic groups exist within F. graminearum, and demonstrated that these groups have different biological properties, especially with respect to their pathogenicity on wheat. There were biologically significant differences between the groups; with group (B) isolates being more aggressive towards wheat than groups (A) and (C). Furthermore, Trichoderma harzianum (Rifai) and Bacillus subtilis (Ehrenberg) which isolated from wheat kernels were screened for antagonistic activity against F. graminearum. They significantly reduced the growth of F. graminearum colonies in culture. In order to gain insight into biological control effect in situ, highly antagonistic isolates of T. harzianum and B. subtilis were selected, based on their in vitro effectiveness, for greenhouse test. It was revealed that T. harzianum and B. subtilis significantly reduced FHB severity. The obtained results indicated that T. harzianum and B. subtilis are very effective biocontrol agents that offer potential benefit in FHB and should be harnessed for further biocontrol applications. The accurate analysis of genetic variation and studies of population structures have significant implications for understanding the genetic traits and disease control programs in wheat. This is the first known report of the distribution and genetic variation of F. graminearum on wheat spikes in Assiut Egypt.

• Journal of Microbiology and Biotechnology
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• v.23 no.12
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• pp.1757-1764
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• 2013

Trichoderma harzianum ZF-2 producing laccase was isolated from decaying samples from Shandong, China, and showed dye decolorization activities. The objective of this study was to optimize its culture conditions using a statistical analysis of its laccase production. The interactions between different fermentation parameters for laccase production were characterized using a Plackett-Burman design and the response surface methodology. The different media components were initially optimized using the conventional one-factor-at-a-time method and an orthogonal test design, and a Plackett-Burman experiment was then performed to evaluate the effects on laccase production. Wheat straw powder, soybean meal, and $CuSO_4$ were all found to have a significant influence on laccase production, and the optimal concentrations of these three factors were then sequentially investigated using the response surface methodology with a central composite design. The resulting optimal medium components for laccase production were determined as follows: wheat straw powder 7.63 g/l, soybean meal 23.07 g/l, $(NH_4)_2SO_4$ 1 g/l, $CuSO_4$ 0.51 g/l, Tween-20 1 g/l, $MgSO_4$ 1 g/l, and $KH_2PO_4$ 0.6 g/l. Using this optimized fermentation method, the yield of laccase was increased 59.68 times to 67.258 U/ml compared with the laccase production with an unoptimized medium. This is the first report on the statistical optimization of laccase production by Trichoderma harzianum ZF-2.

• The Korean Journal of Mycology
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• v.22 no.3
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• pp.276-280
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• 1994

To obtain hybrids producing antagonisms and plant growth promoting effects by intergeneric nuclei transfer, the nuclei were isolated from the protoplasts of Trichoderma harzianum T95 and treated with colchicine. The nuclei were tranferred into protoplast of multi-auxotrophic Gliocladium virens G88 which cannot grow in minimal medium. The nuclei tranferred into protoplasts of G. virens G88 were selected on the regeneration minimal medium containing chloroneb as a haploid inducer. Low transfer frequency of 0.08% was observed with three chemical treatment, however no segregants were found in the intergeneric nuclei transfer. The various types of hybrids with different morphology were detected when different concentration of chloroneb were treated. These morphologies were classified as parental, recombinant and petite type.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.409-415
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• 2005

To control Phytophthora blight of red pepper biologically caused by Phytophthora capsici, we developed Trichoderma harzianum DYMC for commercial product. DYMC was storage at room temperature and was investigated their population every 3 months for 1 year. For investigating the dynamic population of T. harzianum in the pot soils, we applied powder and suspension applications with DYMC, and then investigated for 95 days. The efficacy of powder and suspension applications of DYMC for control of Phytophthora blight of red pepper and plant growth were investigated for 50 days in greenhouse experiment. The population of T. harzianum was decreased at the room temperature for 1 year but there was not statistically significance. After soil treated in the pot with DYMC, the population of Trichoderma spp. was the highest when DYMC powder at 5 g was applied to mix with pot soil, and the population was deceased significantly among treatment means as time goes by ($R^2=0.76$, F=10.5960, P=<.0001). Incidence of Phytophthora blight of, red pepper was significantly reduced among treatment means on 50th day after treated with DYMC ($R^2=0.82$, P=16.4758, P=<.0001). Disease control value was the highest at 62.5% when DYMC powder at 5 g was applied to mix with pot soil. No significant difference (P=0.05) of effects of plant and root growth showed by treated with DYMC on 60th day, except stem. Mixing the application of DYMC powder with soil to control Phytophthora blight of red pepper was greater than suspension application to dilute with water. DYMC could be used as an effective biocontrol agent to control Phythophthora blight of red pepper.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.191-201
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• 2006

Dollar spot caused by Sclerotinia homeocarpa is one of major diseases in putting greens. Microorganisms antagonistic to S. homeocarpa, a pathogen of dollar spot, were primarily screened through in vitro tests, including dual culture method and triple layer agar diffusion method. In vivo tests were also conducted to select the best candidate for a biocontrol microorganism, using pot experiment. Bacillus subtilis EW42-1 and Trichoderma harziaum GBF-0208 were finally selected as biocontrol agents against dollar spot. Relative Performance Index(RPI) was used as a criterion of selecting potential biocontrol agents. B. subtilis EW42-1 and T. harzianum GBF-0208 showed resistance to several agrochemicals mainly used in a golf course. B. subtilis EW42-1 and T. harzianum GBF-0208 suppressed effectively the disease progress of dollar spot like synthetic fungicide tebuconazole in the nursery where dollar spot had seriously occurred. B. subtilis EW42-1 and T. harzianum GBF-0208 have a potential to be biocontrol agents for the control of dollar spot.

• Mycobiology
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• v.45 no.1
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• pp.48-51
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• 2017

The morphological optimization of Trichoderma harzianum was carried out using several surfactants to achieve increased cellulase production. Addition of the surfactants to the culture medium successfully modified the fungal morphology from an aggregated form to a dispersed form. Optimization of the fungal morphology increased cellulase activity up to 177%. The morphologically optimized conditions enhanced the accessibility of the fungus to substrates and thus promoted cellulase production.