Identification of Portuguese traditional grapevines using molecular marker-based strategies

Precise identification is crucial to study and for the valorisation of ancient grapevine varieties, with many synonyms and misidentifications hampering this task. SSR-Multiplex PCR and SNP genotyping combined with HRM were used, to identify 19 varieties present in an ancient Portuguese vineyard. The combination of the methodologies allowed the identification of 18 grapevines, from which 10 were correctly identified by ampelography and the remaining were misidentified. SSR and SNP data retrieved for one sample did not match any profile publicly available, however pedigree analysis suggests it is a new variety. One sample identified as Cerceal Branco presented an unexpected red berry. A sample identified as Malvasia Preta/Preta Roxa also presented a berry colour non coincident with its molecular identification. This suggests they might represent new somatic variants of existent varieties. Three HRM assays were performed to test its robustness in comparison to SSR/SNP results. Molecular identification was successful, revealing possible new variants. HRM revealed to be useful in identifying varieties by melting curve profile comparison against reference material. The results provide a better knowledge of a valuable pool of genetic patrimony: ancient varieties that represent a piece of history and heritage from an important winegrowing region.This work was funded by the Portuguese Foundation for Science and Technology (FCT), Portugal, grant numbers UIDB/04138/2020, and UIDP/04138/2020. We also acknowledge FCT financial support to S.B. (SFRH/BD/146346/2019)