Molecular Analysis of a New Alphapartitivirus from Rhizoctonia solani AG-4 HG III Isolate Rs292

Mycoviruses are ubiquitous among fungal species. However, their diversity and distribution across fungal taxa remain incompletely characterized. Here, we report the identification and molecular analysis of a previously undescribed mycovirus from Rhizoctonia solani AG-4 HG III strain Rs292. This virus was provisionally designated Rhizoctonia solani partitivirus Rs292 (RsPV-Rs292). Its viral genome comprised two sections of double-stranded RNA (dsRNA), measuring 1,924 bp (dsRNA1) and 1,929 bp (dsRNA2), with dsRNA1 consisting of a single open reading frame (ORF1) potentially encoding an RNA-dependent RNA polymerase (RdRp) of 609 residues with conserved catalytic motifs characteristic of partitiviruses. The smaller segment, dsRNA2, contained ORF2, putatively encoding a capsid protein (CP) of 574 residues. BLASTP searches indicated marked sequence similarities of both RdRp and CP with members of the family Partitiviridae. pairwise sequence comparisons of RdRp and CP, RdRp amino acid sequence-based phylogenetic analysis placed RsPV-Rs292 within the genus Alphapartitivirus, supporting its classification as a novel species in this group.