Biodiversity of root-endophytic Trichoderma from Malaysian Borneo

Abstract

Trichoderma root endophytes confer a number of benefits to their host plants including enhanced growth and disease resistance. However, few researchers have examined the taxonomy of Trichoderma species associated with plant roots in tropical regions. Trichoderma is currently used on a wide scale as a replacement for fungicides in plantation forestry in South East Asia. During research evaluating Trichoderma isolates for Acacia mangium bioprotection, root samples were collected from indigenous plants and a variety of exotic ornamental and crop species at sites throughout the Malaysian states of Sarawak and Sabah in Borneo. Collections included over 57 species in 27 plant families. Trichoderma was isolated from surface sterilised roots and isolates identified to species level based on analysis of partial translation elongation factor-la (tefl) sequences. Species present included Trichoderma asperelloides, Trichodermo asperellum, Trichoderma harzianum, Trichoderma reesei, Trichodermo strigosum, and Trichoderma virens. Members of the T. harzianum species complex and T. virens were the most frequently isolated taxa. Analysis of sequence data also indicated that several isolates are likely to represent undescribed Trichoderma species in two main clades. These results suggest that tropical plants are a useful source of novel root-associated Trichoderma that may have potential applications in agriculture and plantation forestry.