• The Korean Journal of Mycology
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• v.31 no.2
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• pp.53-58
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• 2003

Studies were conducted to investigate the changes of teleomorph of Diatrype stigma on bed-log of shiitake (Lentinula edodes) and appearance of secondary harmful fungi from December 1999 to August 2001. The color of stroma was changed from red brown to dark brown after 12 months. The size of ostioles became smaller and the number of ostioles decreased as time passed. Most of the ostioles disappeared after 20 months from toleomorph formation. Perithecia and ascospores were gradually disappeared, and perithecia containing ascospores were observed at 10% of bed-logs tested after 20 months. Concerning the secondary harmful fungi infecting the bedlog of shiitake after teleomorph of D. stigma, Hypoxylon truncatum (Anamorph : Nodulisporium sp.), Schizophyllum commune and Trichoderma spp. were observed on stroma of D. stigma. Penicillium sp. occurred on spore-horn of Libertella sp. (Anamorph of D. stigma). Besides, Hypoxylon howeianum and some species of Myxomycetes were observed. Also, Libertella sp. appeared again at some bed-logs.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1230-1242
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• 2018

In the present work, we reviewed feed mycotoxin-related research and provide potential strategies to overcome feed mycotoxin issues. Cereal grains and cereal byproducts are most easily contaminated by fungus. Fungi in feed ingredients produce secondary metabolites such as aflatoxin, deoxynivalenol, and zearalenone, which are commonly found in feed ingredients. These mycotoxins in animal feeds and ingredients are regulated in many countries. Dietary mycotoxins have detrimental effects on immune systems and growth performance in pigs. A major harmful effect of dietary mycotoxin is reduced feed intake, resulting in deficient energy and nutrient intake and eventually depressed growth of pigs. The reduced energy and nutrient intake may be overcome possibly by increased energy and nutrient concentrations. Dietary supplementation of some mycotoxin binders may reduce the detrimental effects of mycotoxins. However, the effects of mycotoxin binders especially on deoxynivalenol and zearalenone have been reported to be variable depending on classes and concentration of mycotoxin, environmental condition, and type of mycotoxin binders.

• The Plant Pathology Journal
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• v.24 no.3
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• pp.283-288
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• 2008

Plant leaf surface is an important niche for diverse epiphytic microbes, including bacteria and fungi. Plant leaf surface plays a critical frontline defense against pathogen infections. The objective of our study was to evaluate the effectiveness of a starch-based super-absorbent polymer(SAP) combination, which enhances water potential and nutrient availability to plant leaves. We evaluated the effect of SAP on the maintenance of bacterial populations. In order to monitor bacterial populations in situ, a SAP mixture containing Pseudomonas syringae pv. tabaci that expressed recombinant green fluorescent protein(GFPuv) was spray-challenged onto whole leaves of Nicotiana benthamiana. The SAP combination treatment enhanced bacterial robustness, as indicated by disease severity and incidence. Unexpectedly, bacterial numbers were not significantly different between leaves treated with the SAP combination and those treated with water alone. Furthermore, young leaves treated with the SAP combination had more severe symptoms and a greater number of bacterial spots caused by primary and secondary infections compared to young leaves treated with the water control. In contrast, bacterial cell numbers did not statistically differ between the two groups, which indicated that measurement of viable GFP-based bacterial spots may provide a more sensitive methodology for assessing virulence of bacterial pathogens than methods that require dilution plating following maceration of bacterial-inoculated leaf tissue. Our study suggests that the SAP combination successfully increased bacterial aggressiveness, which could either be used to promote the ability of biological agents to control weedy plants or increase the robustness of saprophytic epiphytes against competition from potentially harmful microbes.

• Mycobiology
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• v.47 no.1
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• pp.87-96
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• 2019

Fungi produce various secondary metabolites that have beneficial and harmful effects on other organisms. Those bioactive metabolites have been explored as potential medicinal and antimicrobial resources. However, the activities of the culture filtrate (CF) and metabolites of whiterot fungus (Schizophyllum commune) have been underexplored. In this study, we assayed the antimicrobial activities of CF obtained from white-rot fungus against various plant pathogens and evaluated its efficacy for controlling anthracnose and gray mold in pepper plants. The CF inhibited the mycelial growth of various fungal plant pathogens, but not of bacterial pathogens. Diluted concentrations of CF significantly suppressed the severity of anthracnose and gray mold in pepper fruits. Furthermore, the incidence of anthracnose in field conditions was reduced by treatment with a 12.5% dilution of CF. The active compound responsible for the antifungal and disease control activity was identified and verified as schizostatin. Our results indicate that the CF of white-rot fungus can be used as an eco-friendly natural product against fungal plant pathogens. Moreover, the compound, schizostatin could be used as a biochemical resource or precursor for development as a pesticide. To the best of our knowledge, this is the first report on the control of plant diseases using CF and active compound from white-rot fungus. We discussed the controversial antagonistic activity of schizostatin and believe that the CF of white-rot fungus or its active compound, schizostatin, could be used as a biochemical pesticide against fungal diseases such as anthracnose and gray mold in many vegetables.