Production of Virus Free Seed Potatoes

Elimination of Potato virus X and Potato virus Y was reported from two potato cultivars viz. Multa and Petronese by meristem culture only and thermotherapy followed by meristem culture. Meristems of size ranging from 0.1 mm to 0.4 mm were excised and cultured in liquid media viz. MS + 0.25 mg l-1 calcium pentothenate and incubated under 16 hr photo period at 24 + 1oC. For thermotherapy the potato tubers were incubated at 35oC for three weeks and followed by meristem culture. Meristems sized 0.2 mm to 0.3 mm were found superior for both virus elimination and survival during thermotherapy and without thermotherapy PVY was eliminated easily then PVX. The plantlets developed from meristems were multiplied by performing nodal cutting in MS solid media supplemented with GA3 in different concentration. The media MS + 0.1 ppm GA3 was observed to be superior for multiplication. The variety petronese was observed to have more multiplication rate. Virus free plant lets were transplanted in the screen house and virus free pre-basic seed potatoes were obtained after 12 weeks of transplantation.