In G 1/98, the Enlarged Board concluded that, where specific plant varieties were not claimed individually, the claim was not excluded from patentability under Art. 53(b) EPC, even if it might potentially embrace plant varieties. The Enlarged Board took the view that Art. 53(b) EPC 1973 defined the borderline between patent protection and plant variety protection. The extent of the exclusion for patents was the obverse of the availability of plant variety rights. Since plant variety rights were only granted for specific plant varieties and not for technical teachings which could be implemented in an indefinite number of plant varieties, it was not sufficient for the exclusion from patent protection in Art. 53(b) EPC 1973 to apply that one or more plant varieties were embraced or might be embraced by the claims of the patent application (see also T 475/01).

The Enlarged Board further held that Art. 64(2) EPC 1973 should not be taken into consideration when a claim to a process for the production of a plant variety was examined, in conformity with the established case law according to which the protection conferred by a process patent is extended to the products obtained directly by the process, even if the products are not patentable per se (see chapter II.A.7.1.).

Finally, the Enlarged Board held that the exception to patentability in Art. 53(b) EPC 1973, first part of sentence, EPC 1973, applied to plant varieties irrespective of the way in which they were produced. Therefore, plant varieties containing genes introduced into an ancestral plant by recombinant gene technology were excluded from patentability. The underlying reason for this was that the exclusion in Art. 53(b) EPC 1973 was designed to exclude from patentability subject-matter which was eligible for protection under the plant breeders' rights system. It did not make any difference for the requirements under the UPOV Convention or under the Regulation on Plant Variety Rights, whether a variety was obtained by traditional breeding techniques or genetic engineering. The argument that the EPC legislator had not envisaged the possibility of genetically modified plant varieties and therefore could not have intended to exclude them from patentability could not be accepted – laws were not restricted in their application to situations known to the legislator.