This Article Full Text Full Text (PDF) Supplemental material Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Komon-Zelazowska, M. Articles by Druzhinina, I. S. Search for Related Content PubMed PubMed Citation Articles by Komon-Zelazowska, M. Articles by Druzhinina, I. S. Agricola Articles by Komon-Zelazowska, M. Articles by Druzhinina, I. S.

 Previous Article  |  Next Article 

Applied and Environmental Microbiology, November 2007, p. 7415-7426, Vol. 73, No. 22
0099-2240/07/$08.00+0     doi:10.1128/AEM.01059-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

Genetically Closely Related but Phenotypically Divergent Trichoderma Species Cause Green Mold Disease in Oyster Mushroom Farms Worldwide ^,

Monika Komo-Zelazowska,¹ John Bissett,² Doustmorad Zafari,³ Lóránt Hatvani,⁴ László Manczinger,⁴ Sheri Woo,⁵ Matteo Lorito,⁵ László Kredics,⁴ Christian P. Kubicek,¹ and Irina S. Druzhinina^1*

Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/1665, A-1060, Vienna, Austria,¹ Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed Research Center, Central Experimental Farm, Ottawa, Ontario, Canada K1A 0C6,² Department of Plant Protection, Bu Ali Sina University, Hamadan, Iran,³ Department of Microbiology, Faculty of Sciences, University of Szeged, Közép fasor 52, H-6726 Szeged, Hungary,⁴ Dipartimento di Arboricoltura, Botanica e Patologia Vegetale, Universita degli Studi di Napoli Federico II, Portici, Naples, Italy⁵

Received 11 May 2007/ Accepted 27 August 2007

The worldwide commercial production of the oyster mushroom Pleurotus ostreatus is currently threatened by massive attacks of green mold disease. Using an integrated approach to species recognition comprising analyses of morphological and physiological characters and application of the genealogical concordance of multiple phylogenetic markers (internal transcribed spacer 1 [ITS1] and ITS2 sequences; partial sequences of tef1 and chi18-5), we determined that the causal agents of this disease were two genetically closely related, but phenotypically strongly different, species of Trichoderma, which have been recently described as Trichoderma pleurotum and Trichoderma pleuroticola. They belong to the Harzianum clade of Hypocrea/Trichoderma which also includes Trichoderma aggressivum, the causative agent of green mold disease of Agaricus. Both species have been found on cultivated Pleurotus and its substratum in Europe, Iran, and South Korea, but T. pleuroticola has also been isolated from soil and wood in Canada, the United States, Europe, Iran, and New Zealand. T. pleuroticola displays pachybasium-like morphological characteristics typical of its neighbors in the Harzianum clade, whereas T. pleurotum is characterized by a gliocladium-like conidiophore morphology which is uncharacteristic of the Harzianum clade. Phenotype MicroArrays revealed the generally impaired growth of T. pleurotum on numerous carbon sources readily assimilated by T. pleuroticola and T. aggressivum. In contrast, the Phenotype MicroArray profile of T. pleuroticola is very similar to that of T. aggressivum, which is suggestive of a close genetic relationship. In vitro confrontation reactions with Agaricus bisporus revealed that the antagonistic potential of the two new species against this mushroom is perhaps equal to T. aggressivum. The P. ostreatus confrontation assays showed that T. pleuroticola has the highest affinity to overgrow mushroom mycelium among the green mold species. We conclude that the evolutionary pathway of T. pleuroticola could be in parallel to other saprotrophic and mycoparasitic species from the Harzianum clade and that this species poses the highest infection risk for mushroom farms, whereas T. pleurotum could be specialized for an ecological niche connected to components of Pleurotus substrata in cultivation. A DNA BarCode for identification of these species based on ITS1 and ITS2 sequences has been provided and integrated in the main database for Hypocrea/Trichoderma (www.ISTH.info).

---

* Corresponding author. Mailing address: Research Area Gene Technology and Applied Biochemistry, Institute of Chemical Engineering, Vienna University of Technology, Getreidemarkt 9/1665, A-1060 Vienna, Austria. Phone: 43 1 58801 17202. Fax: 43 1 58801 17299. E-mail: druzhini{at}mail.zserv.tuwien.ac.at

Published ahead of print on 7 September 2007.

Supplemental material for this article may be found at http://aem.asm.org/.

---

Applied and Environmental Microbiology, November 2007, p. 7415-7426, Vol. 73, No. 22
0099-2240/07/$08.00+0     doi:10.1128/AEM.01059-07
Copyright © 2007, American Society for Microbiology. All Rights Reserved.

This article has been cited by other articles:

• Jaklitsch, W. M. (2009). European species of Hypocrea Part I. The green-spored species. SIM 63: 1-91 [Abstract] [Full Text]  
• Druzhinina, I. S., Komon-Zelazowska, M., Kredics, L., Hatvani, L., Antal, Z., Belayneh, T., Kubicek, C. P. (2008). Alternative reproductive strategies of Hypocrea orientalis and genetically close but clonal Trichoderma longibrachiatum, both capable of causing invasive mycoses of humans. Microbiology 154: 3447-3459 [Abstract] [Full Text]  
• Jaklitsch, W. M., Kubicek, C. P., Druzhinina, I. S. (2008). Three European species of Hypocrea with reddish brown stromata and green ascospores. Mycologia 100: 796-815 [Abstract] [Full Text]