This invention relates to polynucleotide sequences encoding a gene that can confer resistance to at least one herbicide. It further relates to plants and seeds of plants carrying chimeric genes comprising said polynucleotide sequences, which enhance or confer resistance to at least one herbicide, and methods of making said plants and seeds. The invention further presents sequences that can be used as molecular markers that in turn can be used to identify the region of interest in corn lines resulting from new crosses and to quickly and efficiently select the best lines for breeding strategies by avoiding sensitive lines.