Cisgenesis, a New Tool for Traditional Plant Breeding, Should be Exempted from the Regulation on Genetically Modified Organisms in a Step by Step Approach

Abstract

Modern potato breeding requires over 100,000 seedlings per new variety. Main reasons are (1) the increasing number of traits that have to be combined in this tetraploid vegetatively propagated crop, and (2) an increasing number of traits (e.g., resistance to biotic stress) originates from wild species. Pre-breeding by introgression or induced translocation is an expensive way of transferring single traits (such as R-genes, coding for resistance to biotic stress) to the cultivated plant. The most important obstacle is simultaneous transfer of undesired neighbouring alien alleles as linkage drag. Stacking several genes from different wild sources is increasing this linkage drag problem tremendously. Biotechnology has enabled transformation of alien genes into the plant. Initially, transgenes were originating mainly from microorganisms, viruses or non-crossable plant species, or they were chimeric. Moreover, selection markers coding for antibiotic resistance or herbicide resistance were needed. Transgenes are a new gene source for plant breeding and, therefore, additional regulations like the EU Directive 2001/18/EC were developed. Because of a strong opposition against genetic modification of plants in Europe, the application of this Directive is strict, very expensive, hampering the introduction of genetically modified (GM) crops and the use of this technology by small and medium-sized enterprises (SMEs). Currently, GM crops are almost the exclusive domain of multinationals. Meanwhile, not only transgenes but also natural genes from the plant species itself or from crossable plant species, called cisgenes, are available and the alien selection genes can be avoided in the end product. This opens the way for cisgenic crops without alien genes. The existing EU directive for GM organisms is not designed for this new development. The cisgenes belong to the existing breeders’ gene pool. The use of this classical gene pool has been regulated already in agreements regarding breeders’ rights. We are proposing a step by step approach starting with a crop and gene specific derogation and monitoring towards a general exemption of cisgenic plants from the Directive. Two examples, i.e. development of cisgenic potato for resistance to Phytophthora infestans and cisgenic apple for resistance to Venturia inaequalis are discussed shortly for illustration of the importance of cisgenesis as a new tool for traditional plant breeding. Cisgenesis is simplifying introgression and induced translocation breeding tremendously and is highly recommended for SMEs and developing countries.