Effective selection and regeneration of transgenic sugarcane plants using positive selection system

We compared the transformation frequency of a positive selection system, which employs an Escherichia coli-derived pmi (phosphomannose isomerase)gene as the selectable marker and mannose as the selective agent, to commonly used negative selection systems of bar (phosphinothricin acetyltransferase)/phosphinothricin (PPT), npt II (neomycin phosphotransferase)/G418 (geneticin), and hpt (hygromycin phosphotransferase)/Hygromycin. Transgenic sugarcane plants were obtained following biolistic transformation of callus with four different selectable marker genes. Under different selective agents, transformed callus was selectively proliferated on MS medium containing 13.57 µM of 2,4-D, regenerated on MS medium with 4.44 µM of BA, 9.29 µM of KT, and 0.89 µM of NAA, and rooted on half of MS medium with 13.38 µM of NAA and 0.44 µM of 6-BA. The results demonstrated that the transformation frequency of 4.2