High efficiency Agrobacterium-mediated transformation of Lycopersicon based on conditions favorable for regeneration.

A successful Agrobacterium-mediated transformation system involving a disarmed Ti plasmid is composed of two stages: transformation of cells and recovery of transformed plants. A tissue transformation system with 34% efficiency was developed using stem segments of the interspecific tomato hybrid Lycopersicon esculentum × L. pennellii. This transformation system emphasizes three factors favoring the recovery of transformed plants: 1) promotion of cell division activity at the inoculation site with kinetin in the incubation medium, 2) promotion of adventitious bud initiation by using organized tissue explants in culture, and 3) application of selection at the shoot development stage of adventitious regeneration.