Identification of viruses prevalent on potato in the Punjab state

Potato (Solanum tuberosum L.) is an important crop of the world after wheat, rice and maize. Punjab being a major potato seed producing state in the country, the potato growing areas in different districts of Punjab were surveyed periodically during 2006–07. Leaf roll, mild mosaic, severe mosaic, crinkling, mottling, mosaic with wavy margins and complex type of symptoms were observed during survey. On the basis of symptoms, these were categorized into seven groups and designated them as PV-1 to PV-7. All the virus groups were tested on four different indicator plants namely, Chenopodium amaranticolor, Nicotiana tabacum, Gomphrena globosa and Physalis floridana. All virus groups produced local lesions on Chenopodium amaranticolor. Nicotiana tabacum reacted with PV-1 and PV-4, Gomphrena globosa reacted with PV-3 and PV-4 and Physalis floridana reacted with PV-5 and PV-7 groups. These indicator plants were also used to study the physical properties of these virus groups. Simultaneously insect transmission studies were carried out on potato cultivar Kufri Badshah. On the basis of physical properties, indicator plants and transmission tests, the virus causing different type of symptoms on potato plants were identified as PLRV, PVX, PVY, PVM, PVA and PVS. Results were further confirmed byperforming serological studies using polyclonal antibodies of different viruses.