Pedigree reconstruction of wine and table grape crossbreeds created in Italy by Giovanni Dalmasso

Starting in 1931, Giovanni Dalmasso carried out intense grapevine breeding activity, creating more than100 wine and table grape crosses. He sought to contribute to the economic development of Italianviticulture, but also left considerable genetic material for further breeding programs.Owing to the current strong interest in the genetic improvement of grapevines, the pedigrees of vari-eties released by breeders must be determined. The aim of this study was to genetically characterize andverify the disclosed pedigrees of Dalmasso’s crosses (IDs). Nuclear microsatellite profiles (n-SSR) of 42ID accessions and 22 genotypes declared as parents were obtained at 22 loci. By cross-validation of allelesize, declared parentages were verified. When one or both disclosed parents were found to be incor-rect due to inconsistent genetic data, putative parent(s) were sought via SSR profile comparison withinthe grapevine molecular database of CNR-Institute for Sustainable Plant Protection, and the probabilityestimated via IDENTITY v. 4.0 software.Through microsatellite analysis, three duplicated genotypes were discovered and twenty ID parentagesout of 39 were confirmed. In 13 IDs, one parent was incorrect, in 2 IDs, both parents were inconsistentwith microsatellite profiles, and in 4 IDs the pedigree could not be verified since the pollen donor wasnot available. Apart from invalidated crosses likely due to pollen contamination, 5 accessions were mis-labelled, either when both parents were invalidated or when two specimens of the same offspring weredifferently labelled. Verification of breeder’s declared parentages revealed 43% of invalidated pedigreeswithin the investigated wine and table cross-breeds. The results provide additional insight into grapevineavailable diversity, and may aid the development of further breeding programs.