Detection and identification of species of the genus Fabavirus by RT–PCR with a single pair of primers

The genus Fabavirus includes three species: Broad bean wilt virus 1 (BBWV-1), BBWV-2 and Lamium mild mosaic virus (LMMV), but a new candidate species, Gentian mosaic virus (GeMV), has been proposed. Analysis of the complete nucleotide sequences of fabaviruses was used to design a pair of conserved primers for specific detection of members of this genus. These primers encompassed the 5′-terminal non-translatable region (NTR) , whose size for BBWV-1, BBWV-2 and GeMV was different. RT–PCR, with this pair of primers, is a rapid and sensitive procedure for diagnosis of fabavirus infections, that also allows identification of distinct species involved in single or mixed infections, based on the size of the amplification products. Moreover, it might allow future discovery of potential new species of this genus.