Two new species of Trichoderma isolated from commercially grown oyster mushroom, Pleurotus ostreatus (oral)

We describe two new Trichoderma species associated with oyster mushroom in Korea. Trichoderma green mould has been one of the most serious diseases of oyster mushroom in Korea. Of these the predominant species are two unrecorded species. We designed as Trichoderma sp. Korean type 1 (Th K1) and Trichoderma sp. Korean type 2 (Th K2), respectively. Th K1 and Th K2 can be distinguished from previously reported Trichoderma species as well as each other in morphological characteristics including growth rate at 35$^{\circ}C$, colony morphology, conidia shape and branch pattern of phialides. Sequence of the ITS region of rDNA, the protein coding translation elongation factor gene(EF-1${\alpha}$), and RNA polymeraseII (RPB2) not only clearly separated Trichoderma sp. Korean types from their closely related T. harzianum biotype but also distinguished them from each other. Analyses of the EF-1${\alpha}$ and RPB2 sequences were found to be more useful for establishing systematic relationships among Trichoderma isolates than those of the ITS sequence. Based on the results of morphological and molecular characteristics. We propose the two Trichoderma sp. Korean types as the new species