Polyclonal antibodies (IgG) against Potato Potyviruses A (PVA), V (PVV) and Y (PVY) ordinary and necrotic strains (PVYO, PVYN), and their alkaline phosphatase or penicillinase conjugates were evaluated for simultaneous and cross detection of PVA, PVV, PVY and tobacco etch virus (TEV). All the three strains of PVY (PVYO PVYN, PVYC) were detected by PVYO and/or PVYN antibodies. The specific monovalent detection of PVA, PVV and PVY was sensitive than any individual cross detection. Both PVA and PVV were poorly cross detected with PVY and vice versa. However, their cross detection improved significantly with the use of 0.05M NH4 HCO3 buffer, ph 8.5 as coating and or extraction buffer and with overnight incubation in both the enzyme assays. PVY antibodies were more reactive than PVA/PVV and dominated the reaction without any interference in simultaneous detection tests with polyvalent conjugate. Use of polyvalent conjugate was found suitable for detection of the three potyviruses in single and multiple infected potato plants. Polyvalent ELISA is more useful for the routine assays.
