New elements helpful in production of virus-free nucleus seed potatoes through meristem tip culture and micropropagation

In microtuber crop of thirteen varieties raised through meristem tip culture and micropropagation the virus freedom varied from PVX, S, Y, M, A and PLRV was found to be 16.7 to 99 per cent in different varieties when tested by ELISA. However, with the introduction of new elements in the system, viz., single node sub culturing, testing of upper half portion of individual plant and transplanting of healthy lower portion in pots and subsequent testing by ELISA has improved the virus freedom between 67 to 100 per cent in Generation 1 and this was further improved to cent percent in generation 2 in all varieties grown for maintenance of virus-free buffer stocks.