Safron (Crocus sativus L.) is one of the world’s most expensive medicinal and aromatic plants, which is extensively grown in Iran. Viral diseases are important causes of serious losses and quality decline in safron production worldwide. To investigate the saffron viromes in the major commercial safron felds in Iran, we used RNA deep sequencing and RT-PCR and found almost complete sequences of three potyviruses, including an unrecorded virus. Assays showed the presence of turnip mosaic virus (TuMV), safron latent virus (SaLV), and an unrecorded potyvirus, which has been tentatively named safron yellow mosaic virus (SYMV). There was no evidence of recombination. The viral genome of the SYMV-IR isolate was 9541 nucleotides long (excluding poly(A) tail) and showed conserved potyvirus-specifc patterns and motifs. It featured two open reading frames, one of which encoded a polyprotein comprised of 3097 amino acids and the other encoded a PIPO protein of 64 amino acids. Phylogenetic analyses and sequence comparisons supported that SYMV is a distinct potyvirus most closely related to members of the bean yellow mosaic virus group (with 54–63% nucleotide identity across the genome). According to our knowledge, this is the frst instance of mixed infections of potyviruses associated with Iranian safron plants naturally. The results expand our understanding of the diversity of viruses that infict a severe limitation on the commercial production of safron in Iran. This has important implications for safron breeding programs globally

Keywords