One-step transformation of two Andean potato cultivars (Solanum tuberosum L. subsp andigena)

Most Agrobacterium-mediated transformation procedures described in the lite rature have proven to be inefficient for transformation of Andean potato cu ltivars. We describe here a more successful method for transformation of tw o of these cultivars, Diacol Capiro (DC) and Parda Pastusa (PP). Leaf expla nts were transformed using vector pBI121 carrying the beta -glucuronidase a nd kanamycin resistance genes. Calli and shoot formation occurred after 5-8 weeks on a selection medium containing 3 mg/l zeatin and I mg/l indole ace tic acid. The shoot regeneration frequency was 28% and 34% for DC and PP, r espectively. Of the kanamycin-resistant plantlets obtained, 51% of those of DC and 13% of those of PP were confirmed to be transformants by histochemi cal assays, polymerase chain reaction analyses and Southern blotting techni ques.