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

Starting in 1931, Giovanni Dalmasso carried out intense grapevine breeding activity, creating more than 100 wine and table grape crosses. He sought to contribute to the economic development of Italian viticulture, 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 varieties released by breeders must be determined. The aim of this study was to genetically characterize and verify the disclosed pedigrees of Dalmasso's crosses (IDs). Nuclear microsatellite profiles (n-SSR) of 42 ID accessions and 22 genotypes declared as parents were obtained at 22 loci. By cross-validation of allele size, declared parentages were verified. When one or both disclosed parents were found to be incorrect due to inconsistent genetic data, putative parent(s) were sought via SSR profile comparison within the grapevine molecular database of CNR-Institute for Sustainable Plant Protection, and the probability estimated via IDENTITY v. 4.0 software.Through microsatellite analysis, three duplicated genotypes were discovered and twenty ID parentages out of 39 were confirmed. In 13 IDs, one parent was incorrect, in 2 IDs, both parents were inconsistent with microsatellite profiles, and in 4 IDs the pedigree could not be verified since the pollen donor was not 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 were differently labelled. Verification of breeder's declared parentages revealed 43% of invalidated pedigrees within the investigated wine and table cross-breeds. The results provide additional insight into grapevine available diversity, and may aid the development of further breeding programs.