Characterisation of the Portuguese grapevine germplasm with 48 single-nucleotide polymorphisms

Background and Aims: Grapevine cultivation has a long tradition in Portugal. Presently, 343 cultivars are legally accepted for wine production. Two hundred and eighty eight accessions from the Portuguese National Ampelographic Collection (including 27 wild grapevines) were genotyped using single-nucleotide polymorphisms (SNP) and compared with the Instituto de Ciencias de la Vid y del Vino-SNP database to reveal identities, synonymies and homonymies. Methods and Results: A set of 48 SNPs was used to profile the 288 accessions and 263 different genotypes were detected. A comparison with the Instituto de Ciencias de la Vid y del Vino-SNP database unveiled 14 new synonymies among Portuguese, Spanish and other international cultivars and confirmed known synonyms and homonyms. Most of the genotyped cultivars are not cultivated in Spain. Clustering using hierarchical and non-hierarchical methods did not reflect the Portuguese geographical viticulture regions. Conclusions: New synonyms and homonyms were identified by SNP profiling of the Portuguese grapevine germplasm. Most of the genotyped cultivars are circumscribed to Portugal. Some cultivars are important in the Iberian context. Significance of the Study This study confirmed the uniqueness of the Portuguese grapevine genetic pool and disclosed many new synonyms within the cultivars authorised for wine production in Portugal. This study confirmed the suitability of the 48 SNP set for grapevine profiling. Results will help to manage the Portuguese germplasm and to adjust the Portuguese legal framework on the denomination of the cultivars authorised for wine production