Table 1.

Characteristics of members of the family Pospiviroidae

Example:	potato spindle tuber viroid (V01465), species Potato spindle tuber viroid, genus Pospiviroid
Genome	Single-stranded circular RNA of 246–375 nt that adopts a rod-like or quasi-rod-like conformation of minimum free energy and contains typical conserved motifs
Replication	Mediated by nuclear DNA-dependent RNA polymerase II, with oligomeric RNAs of (+) polarity cleaved by a type III RNase and circularized by DNA ligase 1
Translation	Absent
Host range	Plants (dicotyledons and some monocotyledons)
Taxonomy	Several genera including >25 species