Potato transformation. A. Shoots formation directly from transgenic microtuber discs of the potato cultivar ‘‘Atlantic’’ after three weeks of culture in the selective medium (MS + 1 mg/L, IAA + 0.2 mg/L, GA3 + 0.5 mg/L, 6-BA + 2 mg/L, ZT + 50 mg/L, kanamycin + 200 mg/L carbenicillin) and incubated under a photoperiod with 16 h light/8 h dark cycles at 24 8C.
B. The roots were formed in about 10 days when green shoots were transferred to the selective rooting medium (MS + 100 mg/L, kanamycin + 200 mg/L carbenicillin). NT: untransformed potato plant as negative control; T1–T4: the transgenic potato plant lines.