The characterization of three isolates of Potato virus Y from khuzestan province according to the coat protein

Potato virus Y is one of the most important damaging viruses with a broad host range. In this research due to detection and isolation of Potato virus Y in turnip fields of Khuzestan province during 2014 growing season, characteristics of three selected isolates (7Tu, 9Tu and 10Tu) from Dezful, Shushtar and Shush cities were investigated. To analyze the host range of the isolates, three selected isolates were mechanically inoculated on some members of Solanaceae, Chenopodiaceae, and Amaranthaceae. All three isolates induced local and systemic symptoms on the leaves of potato, tomato, pepper, datura, and gomphrena plants, but no symptoms were observed on Chenopodium quinoa. Analysis of the PVY partially purified preparations indicated that molecular weight of two protein bands obtained by SDS-PAGE was estimated to be about 33 and 31 KDa. To determine the strain of selective isolates the specific primer pairs CF/OR, NF/NR, OF/OR, and NF/OR were used. Using OF/OR and PVY3TIM/PVNIBIP primers, two fragments with 609 and 1200 bp length respectively were amplified. The CP region in the all three isolates was amplified, cloned and sequenced. The results of all aforementioned tests showed that 7Tu, 9Tu, and 10Tu isolates are probably a member of NTN or W strain groups. According to our knowledge, this is the first report on occurrence of PVY in turnip fields.