DNA marker identification of downy mildew resistance locus Rpv10 in grapevine genotypes

One of the most common and harmful diseases of grapevine is downy mildew, caused by Plasmopara viticola. Cultivars of Vitis vinifera, the basis of high-quality viticulture, are mainly not resistant to downy mildew. Varieties with natural resistance to downy mildew belong to the vine species of North America and Asia (V. aestivalis, V. berlandieri, V. cinerea, V. labrusca, V. amurensis, etc.), as well as Muscadinia rotundifolia. The breeding of resistant cultivars is based on interspecific crossing. Currently, molecular genetic methods are increasingly used in pre-selection work and directly in breeding. One of the major loci of downy mildew resistance, Rpv10, was first identified in the variety Solaris and was originally inherited from wild V. amurensis. DNA markers that allow detecting Rpv10 in grapevine genotypes are known. We used PCR analysis to search for donors of resistance locus among 30 grape cultivars that, according to their pedigrees, could carry Rpv10. The work was performed using an automatic genetic analyzer, which allows obtaining high-precision data. Rpv10 locus allele, which determines resistance to the downy mildew pathogen, has been detected in 10 genotypes. Fingerprinting of grape cultivars with detected Rpv10 was performed at 6 reference SSR loci. DNA marker analysis revealed the presence of a resistance allele in the cultivar Korinka russkaya, which, according to publicly available data, is the offspring of the cultivar Zarya Severa and cannot carry Rpv10. Using the microsatellite loci polymorphism analysis and the data from VIVC database, it was found that Korinka russkaya is the progeny of the cultivar Severnyi, which is the donor of the resistance locus Rpv10. The pedigree of the grapevine cultivar Korinka russkaya was also clarified.