Species Diversity of Trichoderma Associated With Soil In The Zoige Alpine Wetland of Southwest China

Background: The Zoige alpine wetland is one of the most important wetlands in China because of its complex natural environment, abundant ecological resources, and unique climatic conditions. The ecology of soil fungi is poorly understood, and recent comprehensive reports on Trichoderma are not available for any region, including the Zoige alpine wetland ecological region in China. Our results may be used as a reference for a greater understanding of soil microorganism at various ecological regions, ecological rehabilitation and reconstruction and as microbial resources. Results: One hundred soil samples were collected from different soil types and soil layers in Zoige alpine wetland ecological regions in 2013. Using the traditional suspension plating method, a total of 80 Trichoderma strains were isolated. After a preliminary classification of morphological characteristics and the genes glyceraldehyde-3-phosphate dehydrogenase (gpd), 57 strains were representatively selected and eventually identified as seven species via phylogenetic analyses of multilocus sequences based on the genes transcription elongation factor 1 alpha (tef1), encoding RNA polymerase II subunit B (rpb2) and ATP citrate lyase (acl1). Among them, Trichoderma harzianum was the dominant species and had the highest isolation frequency (23%) in this zone, while Trichoderma polysporum and Trichoderma pyramidale were rare species, with isolation frequencies of less than 1%.Conclusions: Our detailed morphological observation and molecular phylogenetic analyses support the recognition of Trichoderma zoigense was described for the first time as a new species.