Abstract: Stem-tips of potato(Solanum tuberosum L.) plants that bear colored tubers were used to produce virus-free plantlets in test tubes. Culture media with hormone combinations in varying concentrations were tested to determine their effects on 21 varieties of plantlets offspring of the potato tissue culture. Meanwhile, RT-PCR was employed to detect any viruses present in the plantlets. The optimum medium for propagating a chosen cultivar, Minshu No.1, was formulated on MS with 0.05 mg·L^-1 NAA, 0.1 mg·L^-1 6-BA, 0.2 mg·L^-1 GA3 and 0.2 mg·L^-1 calcium pantothenate. Different hormone combinations led to significantly different stem-tip differentiation and plantlet formation among the potato varieties. A total of 11 test tube cultivars derived from the stem-tip cultures were virus-free without the contamination of PVX, PVS, PVA, PVS, PVM or PSTVd. They could be the candidate plantlets for field planting.

Key words: color potato, virus-free stem-tip, RT-PCR, virus detection