Identification of Endophytic Trichoderma Species From Oak Trees in Arasbaran Forests Using Morphological and Molecular Characteristics

Trichoderma species have a global distribution, representing dominant mycobiota of soils in different regions. Even though Trichoderma species exhibit strong saprophytic potential, they possess significant epiphytic phase and can penetrate internal tissues of plants without causing any harm to host plant. In recent years, substantial attention has been paid on the identification and interaction of endophytic Trichoderma species with plant hosts. However, there is a huge paucity of knowledge on biodiversity of endophytic Trichoderma species in Iran. The present study was aimed to characterize endophytic Trichoderma species from oak trees in Arasbaran forests. For this purpose, during August-September 2014, samples from twig and trunk of oak trees were collected in the Hatam-baig (Meshgin-Shahr) and the Kaleibar regions. A total number of 23 Trichoderma isolates were recovered from sampled areas. Trichoderma isolates were characterized based on morphological data and sequence data of ITS-rDNA region as Trichoderma atroviride, T. citrinoviride, T.harzianum, T. longibrachiatum and T. polysporum. In a phylogeny inferred based on sequence data of ITS-rDNA region, Trichoderma spp were clustered with the representative sequence of the type strain for each of the species with high bootstrap support. All five species are newly recorded from Arasbaran forests and black oak (Quercus macranthera) is reported as new host for these species. With the identification of these species, it will be possible to evaluate their efficacy in control of plant pathogens and promotion of plant growth.