To date, GYSVd-2 has been found only in few countries and grapevine is the only known natural host of GYSVd-2, which has restricteddistribution in world viticulture. In this study,three GYSVd-2 isolates from three distinct regions of northwest Iran were molecularly characterized. The Iranian GYSVd-2 variants were composedof 360-363 nucleotides sharing a high sequence identity of96-100% with each other, 97-99% with the reference sequence (NC-003612) and99-100%with other GYSVd-2 sequences.In total, six new variants were identified with the most nucleotide changes with respect to the reference variant located in the terminal left(TL) domain, the proposed rod-like secondary structure.Three and five variants showed the deletion of A356and U363in the TL domain, respectively. Also, substitutions of G359 by U, U360 by C and C361 by Uin five variants were found.In contrast, limited nucleotide changes were observed in other domains.In silico analysis showed that some of the nucleotide substitutions would affect the predicted secondarys tructures but possible biological roles on viroid replication and pathogenesis are unknown and would require further investigations.
