Both Rda1 and Rda2 loci showed major dominant effects that suggested qualitative resistance, providing protection against disease symptoms. As a consequence, the molecular markers provided for Rda2 can be used directly for marker-assisted selection of resistant vines at the seedling stage or for stacking Phomopsis resistance alleles along with resistance to major grapevine pathogens. For Rda1, readily assayed markers for MAS can be obtained from the GBS-SNPs provided in Table 3, as described previously (Yang et al. 2016).