Zibibbo Nero Characterization, a Red-Wine Grape Revertant of Muscat of Alexandria

Muscat of Alexandria is known in Italy as Zibibbo. Zibibbo nero, red-wine grapes, is a sport mutation of Zibibbo variety. A biochemical and molecular characterization of berry colour (VvMybA1 and VvMybA2 genes, Vitis vinifera MYeloBlastosis) and aroma Muscat (VvDXS gene, 1-deoxy-D-xylulose 5-phosphate synthase) traits in both Zibibbo cultivars was performed, as well as ampelographic and genetic identification analyses. Molecular investigations were performed also for two putative Zibibbo parents (Moscato Bianco and Triboto), in order to prove the white-to-red shift of the red-skinned mutant. Ampelographic and genetic analysis demonstrated the high similarity between Zibibbo and Zibibbo nero, as well as a comparable aroma profile, characterized mainly by high content of linalool, geranic acid and geraniol (about 70 %). The Zibibbo nero anthocyanin profile was characterized by a high proportion in cyanidin-3-O-glucoside (about 69.23 %). The molecular characterization of VvMybA1 and VvMybA2 locus detected non-functional alleles for white-skinned samples, while also the functional alleles were observed for red-skinned samples. About the VvDXS locus, the aromatic varieties showed the typical pattern of Muscat variety, while Triboto (Zibibbo parent) showed the non-Muscat-like flavour pattern. The colour locus structure of Zibibbo and its putative parents suggested that Zibibbo nero is a berry colour revertant of Zibibbo.