Partial Characterisation of Three Isolates of Potato virus Y

Document Type : Original Article

Authors

Department of Plant Pathology, Faculty of Agriculture, El-Shatby, Alexandria University, Alexandria, Egypt.

Abstract

Field observations indicated that the most common symptoms appearing on naturally infected potato plants growing in El-Beheira, Dakahlia, and Kafr El-Sheikh governorates of Egypt were mild to severe mosaic, chlorosis, mottling, vein banding, blisters, and/or stunting. These symptoms were suspected of being caused by Potato virus Y (PVY) and detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR). The tested specimens demonstrated single RT-qPCR amplification product of 480bp long using a specific pair of primers for PVY coat protein gene. Indirect ELISA using antisera specific to PVY, PVX, PVM and PVS gave positive reaction with PVY antiserum. Based on symptomology and disease severity on Nicotiana glutinosa, three isolates of PVY were obtained and named PVY-Badr, PVY-Wadi (from El-Beheira) and PVY-Talkha (from Dakahlia) then subjected to this study. Reaction of several diagnostic hosts of seven species belonging to two families; Amaranthaceae and Solanaceae upon inoculation with the three isolates elicited different symptoms distinctive to PVY-infection. PVY-Badr and PVY-Talkha isolates developed, respectively, mild to moderate symptoms, while PVY-Wadi isolate induced sever symptoms. The amplified RT-qPCR product of coat protein gene of isolates PVY-Badr and PVY-Wadi were purified and sequenced. The sequences were edited using Chromas Pro. Version 1.34 software and compared with previously subgrouping of 25 virus isolates retrieved from the GenBank database. Alignment of partial sequence and phylogenetic analysis revealed that PVY-Badr closely related to PVYNTN strain, Ireland isolate with similarity percentage of 99.76%, and similarity percentage of 99.42% was scored between PVY-Wadi and PVY-Wilga strain, China isolate.

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