Abstract: Under the tendency rapid development of geneticallly modified orgnism(GMO), it is necessary to obtain the marker-free transgenic plants. At present,the marker-free transgenic technologies include co-transformation,site-specific recombination, transposons, homologous recombination and so on. This paper summarizes the character, the theories and research progress of marker-free and redundant sequence-free transgenic technologies, which are extensively used in recent research. Then, it also prospects the application potential of the safe transgenic technologies for the rapid commercialization of GMOs.

Key words: selectable marker gene, co-transformation, site-specific recombination; , transposons, homologous recombination