Field Evaluation and Enzyme-Linked Immunosorbent Assay Detection of Potato Leaf Roll Virus, Potato Virus X and Potato Virus Y in Potato Germplasm

Polerovirus- potato leaf roll virus (PLRV), Potyvirus- potato virus Y (PVY) and Potexvirus- potato virus X (PVX) is more destructive and well distributed throughout the Pakistan. Incidence has been reported to be as high as 90%, 25%, and ≥ 15%, respectively in the potato growing regions. To find out the source of resistance, twenty-nine virus free potato varieties were grown under field conditions with good agricultural practices. The disease severity of PLRV, PVY and PVX was recorded to determine the level of resistance of the potato varieties according to the disease rating scale. Infectivity and biological assay of all twenty-nine varieties were done in green house on potato, Datura stramonium, Nicotiana glutinosa and Physalis floridana. Non-inoculated plants were served as control. Leaf samples from potato varieties were collected for serological detection of PLRV, PVY and PVX by Double antibody sandwich Enzyme-Linked Immunosorbent Assay (DAS-ELISA). Out of twenty nine varieties, none of the variety was resistant to PLRV although three varieties; Mirrato, 394021-120 and Orla were moderately resistant. Only FD 48-4 and TPS 9813 showed resistance to PVX and PVY. While FD 3-10, FD 9616 and FD 37-13 were moderately to PVX and PVY. Rest of the varieties was found susceptible to all three viruses.