Agrobacterium tumefaciens was used to transform fiber flax with the pBITUBA8 plasmid carrying the mutant alpha-tubulin gene imparting resistance to dinitroaniline herbicides and the nptII selective marker gene imparting resistance to canamycin. The transformants were selected in parallel on media containing canamycin and trifluralin (a dinitroaniline herbicide). The transgenic nature of the resultant regenerants resistant to dinitroaniline herbicides was confirmed by means of Southern blotting and polymerase chain reaction (PCR) analysis using specific probes for the ntpll gene and the gene of alpha-tubulin.