First report of the incidence of potato virus Y in some ornamental plants in Iran

During the surveys conducted from green space in Shiraz City, Iran, in the summer of 2022, leaf chlorosis and mosaic symptoms were observed on the leaves of black-eyed-susans (Rudbeckia hirta), a  Dahlia sp., and Mexican Petunia (Ruellia brittoniana) plants. Total genomic RNA was separately extracted from 10 symptomatic and one symptomless (negative control) leaf samples and subjected to Reverse Transcription-Polymerase Chain Reaction (RT-PCR) using a potyvirus degenerate primer pair (NIb3R, NIb2F). RT-PCR resulted in the amplification of an approximately 350 bp DNA fragment in all symptomatic samples, while no such fragment was amplified from the symptomless plant. The amplified DNA fragment was subjected to Sanger sequencing, and its size was determined to be exactly 350 bp, and confirmed that it belongs to the Nib gene of potato virus Y (PVY). The nucleotide (nt) sequence of the amplicons was compared with the nt sequence of the same region of some other PVY isolates that were available in the GenBank. The sequence analysis revealed that the R. brittoniana isolate exhibited the highest (98.8%) similarity to a PVY isolate from the USA with the Acc. No. of KY_848029.1. Similarly, the R. hirta and the Dahlia isolates showed the highest (98.3%, 98.4 %, respectively ) similarity to a PVY isolate from Kazakhstan with the Acc. No. of ON_583980.1.