Mycovirome analysis unveils rich viral diversity and evolutionary insights in Fusarium pseudograminearum

Mycoviruses are widely distributed across major fungal clades and have significant potential as biocontrol agents, particularly in phytopathogenic fungi, which cause substantial economic losses in agricultural production. Fusarium pseudograminearum , a prominent causal agent of wheat crown rot worldwide, remains underexplored with respect to its associated mycoviral species . To explore the mycovirome of F. pseudograminearum , metatranscriptomic sequencing was performed on 400 isolates of this fungal pathogen in this study. A diverse array of 80 contigs associated with mycovirus species was identified, of which 34 represent novel species. Genome-type analysis revealed 52 positive-sense single-stranded RNA (+ssRNA), 18 negative-sense ssRNA (-ssRNA), and 10 double-stranded RNA (dsRNA) viruses. Classification using BLASTp and phylogenetic analysis of RNA-dependent RNA polymerase (RdRp) sequences placed these mycoviruses into 12 distinct evolutionary lineages. Mitoviruses constituted nearly half (47.5%) of the identified mycoviruses, while phenuiviruses accounted for 11.25%. Intriguingly, multiple mycoviruses shared homology with plant viruses, suggesting possible evolutionary links. This study provides the first comprehensive mycovirome analysis of F. pseudograminearum , uncovering substantial viral diversity. The findings expand our understanding of mycoviral communities and offer new perspectives for studying virus evolution.