Two new species of Trichoderma from agricultural soils in China

Abstract Trichoderma constitutes a species-rich, globally widespread fungal genus with important agricultural application potential. Multilocus phylogenetic analyses and pairwise nucleotide similarity assessments are performed on isolates representing two putative novel taxa recovered from agricultural soils sampled across multiple Chinese provinces. Phylogenetic reconstructions based on concatenated rpb2 and tef1 barcode datasets reveal that all isolates of each candidate taxon form well-resolved, independent monophyletic lineages clearly segregated from every formally published species: Trichoderma yunguichuanense falls within Clade 1 ( Harzianum Clade), and T. paramoravicum belongs to Clade 2 ( Moravicum / Semiorbis Clade). Pairwise nucleotide comparisons between the collected isolates and their phylogenetically adjacent reference strains yield similarity values below the dual conspecific cutoffs of ≥ 99% for rpb2 and ≥ 97% for tef1 , the molecular thresholds specified in Trichoderma barcode guidelines. Meanwhile, multilocus phylogeny and pairwise similarity data demonstrate that T. longibrachiatum , T. awajun , and T. bissettii simultaneously reach the conspecific identity benchmarks, which confirms the three taxa constitute a single conspecific complex. Detailed descriptions of colony features on four standardized culture media and microscopic morphological structures are provided. This taxonomic study enriches the documented diversity of Trichoderma resources distributed across Chinese agricultural ecosystems.