Petunia (Petunia hybrida).

Petunia hybrida genetic transformation continues to be a valuable tool for genetic research into biochemical pathways and gene expression, as well as generating commercial products with varying floral colors. In this chapter, we describe a simple and reproducible genetic transformation protocol for generating transgenic petunia plants harboring a gene of interest and selectable marker. The system utilizes Agrobacterium tumefaciens for transgene integration with plant recovery via shoot organogenesis from leaf explant material. Selection for transgenic plants is achieved using the bar gene conferring resistance to glufosinate or nptII gene for resistance to kanamycin. Transformation efficiencies of around 10% are achievable with shoots being recovered about 8 wk after transgene insertion and rooted plants transferred to the greenhouse about twelve weeks after inoculation.