A novel alternavirus with three dsRNA segments from Fusarium pseudograminearum, the pathogen of Fusarium crown rot in wheat.

Three dsRNA segments were detected in Fusarium pseudograminearum strain CF14029, a pathogen causing Fusarium crown rot in China. Characterization and sequence analysis confirmed that these dsRNA sequences originated from the same virus. The viral genome consists of three dsRNA segments: dsRNA1 (3,560 nt in length), encoding an RNA-dependent RNA polymerase (RdRp), dsRNA2 (2,544 nt in length), encoding a hypothetical protein, and dsRNA3 (2,478 nt in length), encoding a putative coat protein (CP). Phylogenetic analysis based on the RdRp and CP amino acid sequences revealed a high degree of similarity of this virus to members of the genus Alternavirus, family Alternaviridae, isolated from other Fusarium fungi. As a novel member of the genus Alternavirus, this virus was provisionally named "Fusarium pseudograminearum alternavirus 1" (FpgAV1). Like other alternaviruses found in Fusarium species, the positive-sense strand of each genomic dsRNA of FpgAV1 possesses a poly(A) tail and a distinctive 5'-terminal octamer sequence (5'-GCT GTG TG-3'). This is the first report of the genomic sequence of an alternavirus identified in F. pseudograminearum.