Establishment of an efficient transgenic selection system and its utilization in Saccharum officinarum

Transgenic strategy plays an important role in the biological study and breeding of sugarcane. However, the efficiency of sugarcane transgenic systems remains disappointing to breeders. Various cultivated varieties are recalcitrant to genetic transformation, and only a few sugarcane research institutes could successfully obtain positive transgenic lines. In our previous research, three kinds of sugarcane transgenic selection systems, namely, the PMI/Mannose, CP4-EPSPS/glyphosate, and bar/Basta selection systems, were successfully established. Among these systems, the bar/Basta selection system was the most efficient. By applying this selection system, 10 or more transgenic shoots could be obtained from a gram of embryogenic calluses. In addition, the resistant shoots obtained after screening were almost 100% positive for the molecular assay, and all of the transgenic shoots showed high herbicide tolerance in lab tests and field trials. Herein, the key points/steps, advantage and contribution to sugarcane studies and breeding in China of the efficient bar/Basta sugarcane transformation system are presented and discussed.