Simple DNA marker system reveals genetic diversity of MYB genotypes that determine skin color in grape genetic resources

Grape skin color is determined mainly by the quantity and composition of anthocyanins, and the MYB genotype at the color locus on chromosome 2 is the major genetic determinant of anthocyanin biosynthesis. Recently, poor coloration of grape berry skin has become a common problem caused mainly by high temperatures during maturation. In the present study, we developed a simple DNA marker system for predicting the MYB genotype at the color locus. Our sample preparation method for PCR and efficient DNA markers can distinguish many MYB genotypes derived from V. vinifera and interspecific hybrid grapes simultaneously. Furthermore, we constructed a database of the relationship between MYB genotype at the color locus and the “Skin color”, “Species”, “Region of origin”, and “Utilization” categories in more than 700 grape genetic resources. We found a significant association between MYB genotypes and each of the four categories. This novel DNA marker system and the database of MYB genotypes will contribute to the development of new grape varieties with well-pigmented berries despite global atmospheric warming. This study may also contribute to elucidation of the evolutionary differentiation of MYB genotypes at the color locus in Vitis species.