AGROBACTERIUM-TUMEFACIENS-MEDIATED TRANSFORMATION OF SOLANUM-BREVIDENS AND SOLANUM-TUBEROSUM CV PITO

An Agrobacterium tumefaciens-mediated transformation procedure was developed for the non tuber-bearing, diploid wild potato species Solanum brevidens, and the tetraploid S. tuberosum cv. Pito. Cointegrative transformation vectors pGV2260 and pGV3850, and binary vector pGUS-INT were employed in transformation of S. brevidens and Pito, respectively. Leaf and stem explants of S. brevidens and microtuber discs of Pito were precultured 24 h, and cocultivated 48 h on solidified callus induction medium with a 24-h liquid culture of A. tumefaciens C58C1 diluted 1:10 with liquid MS medium. Explants were rinsed with cefotaxime solution (500 mg/l) to remove Agrobacterium, grown without the selective agent kanamycin on solified callus induction media for 14 days, and then exposed to kanamycin selection for the first seven days on callus induction medium and subsequently on shoot regeneration medium. Shoots regenerated faster from stem explants than from leaf explants. Up to 49% and 57% of the transformed leaf explants of S. brevidens and microtuber discs of Pito, respectively, produced transformed shoots.