The integration of conventional plant breeding and plant transformation is necessitated by the fact that, prior to the gene technological phase, traditional breeding methods have to be used to develop agronomically valuable homozygous genotypes which can then be modified for a gene or genome segment by means of gene manipulation techniques. Once the genotype selected by means of conventional breeding has been transformed, traditional methods are again used to examine the agronomic properties of the lines developed from the transgenic plant and the stability of the transgenic variety, following the DUS criteria elaborated by UPOV. The seed production of genetically modified plant varieties must be safe and economical and the cultivation of the variety should contribute to the sustainable development of up-to-date crop production.