Hypocrea peltata: a mycological Dr Jekyll and Mr Hyde?

Area of Science:

• Mycology
• Fungal Taxonomy
• Molecular Phylogenetics

Background:

• Hypocrea peltata is a subtropical fungus with distinctive morphological traits.
• Unlike most related species, it lacks a Trichoderma anamorph and possesses unusually large stromata.
• These atypical features raise questions about its precise generic classification.

Purpose of the Study:

• To clarify the taxonomic placement of Hypocrea peltata.
• To investigate its phylogenetic relationship within the Trichoderma/Hypocrea complex.
• To identify the genetic basis for its unique characteristics.

Main Methods:

• Morphological analysis of stromata and ascospores.
• Culturing and observation of fungal anamorphs.
• Molecular phylogenetic analysis using internal transcribed spacer (ITS), 28S nuclear large subunit (LSU) rDNA, and RNA polymerase subunit II (rpb2) gene sequences.

Main Results:

• Hypocrea peltata exhibits large stromata and produces only indehiscent aleuriospores, lacking the typical Trichoderma anamorph.
• Phylogenetic analysis of ITS, LSU, and rpb2 sequences reveals that H. peltata represents a unique lineage within the Trichoderma/Hypocrea group.
• The genetic sequences of H. peltata match those of an previously unidentified Hypocreaceae species isolated from human lung tissue.

Conclusions:

• Despite its unusual morphology, molecular data strongly support the placement of Hypocrea peltata within the Hypocreaceae family.
• The study highlights a unique evolutionary path for this species.
• The genetic identity between H. peltata and the isolate from pulmonary fibrosis suggests a potential link or commonality.