title: Occurrence of two different species of mitoviruses in the European race of Gremmeniella abietina var. abietina, both hosted by the genetically unique Spanish population.
abstract: The genetic structure of the genus Mitovirus community hosted by the European pathogenic conifer fungus Gremmeniella abietina var. abietina was investigated. Gremmeniella abietina is a species complex with a divergent mycovirus community, composed mainly of Totivirus, Partitivirus, and Mitovirus species. In this work, the total doubled-stranded (ds)RNA from 353 isolates from Canada, Finland, Spain, Switzerland, Turkey, and USA was extracted to look for the presence of a ca. 2.5 kb band typical of mitoviruses' genomes. Based on the banding data, 60 partial RNA-dependent RNA polymerase (RdRp) DNA sequences (ca. 500 bp) were amplified with reverse transcription-polymerase chain reaction (RT-PCR) and sequenced. Two distantly related mitovirus groups (species) were observed in the clustering analysis, one of them related to GMV1-1 and the other one related to a new putative species described in this study, GMV2-1. Viruses in these two clusters seemed to be subjected to purifying selection. The cluster with GMV1-1 included viruses observed in the Finnish biotype A and Spanish strains, whereas the cluster including GMV2-1 was composed of viruses of the Finnish biotype B and one from the Spanish population. Thereby, the Spanish population of G. abietina harboured mitovirus strains occurring in both biotype A and B strains, and it is the first one hosting distantly related mycoviruses of a single genus in one population of G. abietina. This may suggest that horizontal transmission of viruses could have occurred between biotype B and the Spanish population.
authors.affiliation: Sustainable Forest Management Research Institute, University of Valladolid, INIA, 34004 Palencia, Spain. lbotella@pvs.uva.es
authors.forename: Leticia
authors.initials: L
authors.lastname: Botella
authors.forename: Tero T
authors.initials: TT
authors.lastname: Tuomivirta
authors.forename: Stephane
authors.initials: S
authors.lastname: Vervuurt
authors.forename: Julio J
authors.initials: JJ
authors.lastname: Diez
authors.forename: Jarkko
authors.initials: J
authors.lastname: Hantula
mesh_terms: D001203:Ascomycota / Q000145:classification / Q000235:genetics / Q000302:isolation & purification / Q000821:virology*; D005060:Europe; D058507:Host Specificity; D008969:Molecular Sequence Data; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D012328:RNA Viruses / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D014197:Trees / Q000382:microbiology