*3.6. Correlation Analysis between Anthocyanin-Synthesis-Related Structural Genes and VvMYBA1 and VvMYBPA1 Regulatory Genes among Bud Sport Varieties*

In the 'Italia' vs. 'Benitaka' bud sport group, *VvMYBA1* and *VvUFGT* showed a significant positive correlation, and *VvMYBA1* may directly regulate *VvUFGT* expression to regulate anthocyanin synthesis. *VvMYBA1* was positively correlated with *VvCHS*, *VvCHI*, *VvF3H*, and *VvLDOX* in the 'Muscat of Alexandria' vs. 'Flame Muscat' bud sport group, while *VvMYBA1* was not significantly correlated with *VvUFGT* (Figure 6A,B). The mechanism of *VvMYBA1* regulation of the anthocyanin synthesis pathway in the pericarp was different between the 'Italia' vs. 'Benitaka' bud sport group and the 'Muscat of Alexandria' vs. 'Flame Muscat' bud sport group. The gene expressions of *VvMYBPA1* and *VvFLS* in the 'Italia' vs. 'Benitaka' bud sport group were positively correlated, and *VvMYBPA1* may directly regulate the expression of *VvFLS*. There was no significant correlation between *VvMYBPA1* and anthocyanin synthesis structural genes in the bud sport group of 'Muscat of Alexandria' vs. 'Flame Muscat', which may not be directly involved in the regulation of anthocyanin synthesis (Figure 6C,D).

**Figure 6.** Correlation between anthocyanin synthesis structural genes and *VvMYBA1* and *VvMYBPA1* regulatory genes in two bud sport groups. (**A**) Correlation between anthocyanin synthesis structural genes and *VvMYBA1* regulatory gene in 'Italia' vs. 'Benitaka' bud sport group; (**B**) 'Muscat of Alexandria' vs. 'Flame Muscat' bud sport group anthocyanin synthesis structural genes and *VvMYBA1* regulatory gene correlation; (**C**) correlation between anthocyanin synthesis structural genes and *VvMYBPA1* regulatory gene in 'Italia' vs. 'Benitaka' bud sport group; (**D**) 'Muscat of Alexandria' vs. 'Flame Muscat' bud sport group anthocyanin synthesis structural genes associated with *VvMYBPA1* regulatory gene. '\*,\*\*' represents the two groups of data reached a significant level, '\*' represents *p* < 0.05, '\*\*' represents *p* < 0.01.
