Complete genome sequence of a novel iflavirus from wheat sawfly (Dolerus tritici)

Little is known about the commensal viruses in wheat sawfly, Dolerus tritici , which is an important agricultural insect feeding on wheat leaves. Here, we identified a novel single positive-strand RNA virus from the larvae of wheat sawfly collected in northern China through RNA sequencing, and then determined its complete genome sequence by rapid amplification of cDNA ends. The complete genome consists of 9,594 bp in size including a poly A tail at 3′ terminus, which is predicted encoding a 326.3 kD polyprotein. The phylogenetic tree analysis of deduced polyprotein revealed that this RNA virus was clustered in the clade with deformed wing virus in genus Iflavirus , family Iflaviridae. The full genome of this RNA virus shows 38.9-50.0% sequence identities with other iflaviruses. Sequence identity at the amino acid level of coat proteins shows this RNA virus has highest identity with slow bee paralysis virus at 33.6%, which no more than 90% suggesting that it is a new member in the genus Ifavirus . Thus, we tentatively designated as “Dolerus tritici iflavirus 1” (DtIV1). According to our knowledge, this is the first report of the commensal virus in wheat sawfly.