Notes on Genus: Betacryptovirus


Type member: White clover cryptic virus 2


General Description

This is one of 2 plant virus genera in the family Partitiviridae. Both genera have double stranded bipartite RNA genomes, isometric particles, and cause latent infections in plants. The name is from the Greek crypto, meaning "hidden". Members of this genus have larger particles (38nm) than those of the genus Alphacryptovirus and are not serologically related to them.


Virions isometric (icosahedral), not enveloped, 38 nm in diameter.

Virions composed of 24% nucleic acid.


Bipartite, linear, double stranded RNA, typically of about 2.45 and 2.35 kbp.

Genus Genomic Organization

The RNAs are both monocistronic. RNA1 encodes the coat protein and RNA2 a polymerase.

Type Member Genomic Organization

  • RNA1 (2435 nt): encodes an RNA polymerase of 87 kDa
  • RNA2 (2348 nt): encodes the coat protein of 76 kDa