Novel and divergent bipartite mycoviruses associated with the ectomycorrhizal fungus Sarcosphaera coronaria

Abstract

Members of the family Partitiviridae are reported from a variety of fungal and plant taxa. After dsRNA-preparation, deep sequencing, and bioinformatics, we here reveal the existence of various divergent partitiviruses co-infecting the ectomycorrhizal fungus Sarcosphaera coronaria, symbiotically associated with the pine species Pinus brutia in Turkey. A total of 75 complete or nearly complete sequences related to the members of Alphapartitivirus and Betapartitivirus, were detected from the ascocarp sample of the fungal isolate. Two of the identified partitivirus genome segments encoding for partitiviral capsid protein represent evolutionarily distinct members of Alphapartitivirus, indicating that they may have diverged in the presence of long spatial isolation. In an attempt to match the two genome segments of the identified partitiviruses and distinguish individual species co-inhabiting a single host, nine possible genome segment pairs were identified.

Keywords: Ectomycorrhizal fungus; High-throughput sequencing; Multiple infections; Partitiviridae.