Large-scale Trichoderma diversity was associated with ecosystem, climate and geographic location

Abstract

Trichoderma is one of the most abundant and important fungal genera globally, inhabiting diverse terrestrial and aquatic ecosystems. The aim of this work was to investigate, quantitatively, if environmental factors influenced the diversity of Trichoderma communities over a large land mass. Over 1200 samples of Trichoderma spp. were collected from 40 sites, covering diverse ecosystems, climates and geographic regions of China. Pure mycelia were used to extract genomic DNA to sequence the internal transcribed spacer and translation elongation factor 1‐α regions. Using the approaches of operational taxonomic unit clustering and species annotation, we identified that ecosystem, climatic factors and geographic distance were the primary determinants of the diversity and composition of the whole Trichoderma communities and two clade communities. Ecosystem type significantly explained 24%–48% variation in Trichoderma species composition. Trichoderma diversity was increased with both rainfall (r = 0.52) and mean temperature (r = 0.40). Trichoderma community similarity decreased with geographic distance, with turnover rates (correlation coefficient values) of 0.22–0.39. A group of Trichoderma isolates from diverse environments in our collection were identified as taxonomically novel species. Overall, ecosystem and climatic factors significantly influenced the diversity of Trichoderma spp. within microbial communities across the large landmass of China.