Potato Virus Y (PVY) is the most common and destructive virus found in most potato production area. It is the type species of the genus Potyvirus, family Potyviridae. The viral genome consists of a single-stranded, positive-sense RNA molecule about 9.7 kb in length, with a VPg protein covalently attached to its 5`end and a poly-A tail at its 3`end. The viral RNA encodes a single large polypeptide, which is cleaved by three virus-encoded proteases into nine products. It is a serious problem for production of potato globally and more specifically in potato seed production industry. It is being transmitted by 40 species of aphid in a non persistant manner. Globally the seriousness of the problem has been significantly amplified with the emergence of new strains i.e., PVY O , PVY N , PVY C , PVY Z , and PVY E in addition to recombinant strains i.e., PVY N-Wi , PVY NTN . In India the strains PVY were first reported in 1975, PVY C on potato in 1981, PVY N on tomato in 1987. Symptom expression varies considerably with potato cultivars which are further complicated by diver’s strain of PVY.Generally the plants will be stunted with mild or severe mosaic, veinal necrosis. Ordinary strain (PVY O ) and stipple-streak strain (PVY C ) causes necrosis, yellowing of leaflets and premature leaf drops. PVY NTN strains cause mild mosaic and clearly visible raised necrotic ring spots on the tuber surface which later become sunken and skin cracking.