EN
Since the first reports of successful plant transformation appeared, there have been steady improvements of the transformation methods. Nowadays, transgenic plants without the incorporation of selection genes for antibiotic or herbicide resistance would be the only ones acceptable to the public, so elimination of these genes from transgenic crops prior to their field release and commercialization seems inevitable. Several strategies have been developed to generate marker-free transgenic plants, including: positive selection, alternative marker genes, co-transformation, site-specific recombination, transpozon-mediated approaches and intrachromosomal homologous recombination. The efficiency of these methods is various as comparing to the traditional marker assisted selection - higher in case of alternative procedures and lower in others.