Genetic and Phenotypic Characterization of Cryphonectria hypovirus 1 from Eurasian Georgia

Viruses. 2018 Dec 3;10(12):687. doi: 10.3390/v10120687.


Cryphonectria hypovirus 1 (CHV-1) infects the chestnut blight fungus Cryphonectria parasitica and acts as a biological control agent against this harmful tree disease. In this study, we screened the recently characterized C. parasitica population in Eurasian Georgia for the presence of CHV-1. We found 62 CHV-1 infected C. parasitica isolates (9.3%) among a total of 664 isolates sampled in 14 locations across Georgia. The prevalence of CHV-1 at the different locations ranged from 0% in the eastern part of the country to 29% in the western part. Sequencing of two specific regions of the viral genome one each in ORFA and ORFB revealed a unique CHV-1 subtype in Georgia. This subtype has a recombinant pattern combining the ORFA region from the subtype F2 and the ORFB region from subtype D. All 62 viral strains belonged to this Georgian CHV-1 subtype (subtype G). The CHV-1 subtype G strongly reduced the parasitic growth of C. parasitica isolates from Georgia, with a more severe effect on the European genepool compared to the Georgian genepool. The CHV-1 subtype detected in Georgia provides a valuable candidate for biological control applications in the Caucasus region.

Keywords: Castanea sativa; Cryphonectria parasitica; biological control; chestnut blight; mycovirus; populations study.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ascomycota / growth & development
  • Ascomycota / virology*
  • Biological Control Agents
  • Fungal Viruses / classification
  • Fungal Viruses / genetics*
  • Genome, Viral
  • Georgia (Republic)
  • Open Reading Frames
  • Phenotype
  • Plant Diseases / microbiology
  • RNA Viruses / classification
  • RNA Viruses / genetics


  • Biological Control Agents

Supplementary concepts

  • Cryphonectria hypovirus 1