title: Biological control of rice brown spot with native isolates of three Trichoderma species.
abstract: Brown spot caused by Bipolaris oryzae is an important rice disease in Southern coast of Caspian Sea, the major rice growing region in Iran. A total of 45 Trichoderma isolates were obtained from rice paddy fields in Golestan and Mazandaran provinces which belonged to Trichoderma harzianum, T. virens and T. atroviride species. Initially, they were screened against B. oryzae by antagonism tests including dual culture, volatile and nonvolatile metabolites and hyperparasitism. Results showed that Trichoderma isolates can significantly inhibit mycelium growth of pathogen in vitro by producing volatile and nonvolatile metabolites Light microscopic observations showed no evidence of mycoparasitic behaviour of the tested isolates of Trichoderma spp. such as coiling around the B. oryzae. According to in vitro experiments, Trichoderma isolates were selected in order to evaluate their efficacy in controlling brown spot in glasshouse using seed treatment and foliar spray methods. Concerning the glasshouse tests, two strains of T. harzianum significantly controlled the disease and one strain of T. atroviride increased the seedling growth. It is the first time that the biological control of rice brown spot and increase of seedling growth with Trichoderma species have been studied in Iran.
authors.affiliation: Department of Plant Pathology, Gorgan University of Agriculture Science and Natural Resources , Gorgan, Golestan , Iran.
authors.forename: Elham
authors.initials: E
authors.lastname: Khalili
authors.forename: Mehdi
authors.initials: M
authors.lastname: Sadravi
authors.forename: Shahram
authors.initials: S
authors.lastname: Naeimi
authors.forename: Vahid
authors.initials: V
authors.lastname: Khosravi
keywords: Biocontrol; Rice brown spot; T. atroviride; T. virens; Trichoderma harzianum
references.citation: FEMS Microbiol Lett. 2005 Oct 15;251(2):251-7
references.pmid: 16165315
references.citation: Mycopathologia. 2007 Aug;164(2):81-9
references.pmid: 17592758
references.citation: Microbiology (Reading). 2001 Nov;147(Pt 11):2943-50
references.pmid: 11700345
references.citation: Phytopathology. 2006 Feb;96(2):190-4
references.pmid: 18943924
references.citation: Fungal Genet Biol. 2003 Apr;38(3):310-9
references.pmid: 12684020
references.citation: Appl Environ Microbiol. 2000 May;66(5):1890-8
references.pmid: 10788356
references.citation: Mycopathologia. 1997;137(2):115-24
references.pmid: 16284721
references.citation: Int Microbiol. 2004 Dec;7(4):249-60
references.pmid: 15666245