Genetic transformation of plants often results in multiple copies of the introduced DNA at a single locus.  To ensure that only a single copy of a foreign gene resides in the plant genome, we used a strategy based on site-specific recombination.  The transformation vector consists of a transgene flanked by recombination sites in an inverted orientation.  Regardless of the number of copies integrated between the outermost transgenes, recombination between the outermost sites resolves the integrated molecules into a single copy.  An example of this strategy has been demonstrated with wheat transformation, where four of four multiple-copy loci were resolved successfully into single-copy transgenes.