Screening grape hybrid families with molecular markers linked to resistance genes

Gene pyramiding is a potential method to breed new grape cultivars with durable disease resistance. The use of resistance gene-linked DNA markers consider-ably reduces the volume of breeding experiments, since it makes possible the identifi-cation of progeny seedlings that have inherited the desired gene shortly after germination, and permits the reduction of population size. Saturating the grape genome with molecular markers, the construction of genetic linkage maps and the recent publication of the Vitis vinifera genome sequence allow for the direct selection the desired genotype. To combine powdery and downy mildew resistance genes Kozma et al. (Research Institute of Viticulture and Enology, Pecs) made the following crosses: ?BC4? (?VRH 3082-1-42?) × V. vinifera ?Kishmish vatkana?, ?BC4? × V. vinifera ?Kishmish moldavskiy?, V. vinifera ?Genuai zamatos? × V. vinifera ?Kishmish vatkana?, (?Lasta? × V. vinifera ?Dzhandzhal kara?) × (V. vinifera ?Katta kurgan? × V. vinifera ?Perlette?). Our aim was to select individuals containing powdery (PM) and/or downy mildew (DM) major resistance genes of different origin (Muscadinia rotundifolia-RUN1, RPV1, V. vinifera-REN1, and PM and DM QTLs of Seyve-Villard) with SSR markers. We compared the symptomless progenies derived from the cross ?BC4? × ?Kishmish vatkana? and (?Lasta? × ?Dzhandzhal kara?) × (?Katta kurgan? × ?Perlette?) using resistance linked markers. We observed that alleles of SSR markers linked to the PM resistance gene REN1 in the linkage group 13 are the same, so the PM resistance genes of ?Kishmish vatkana? and ?Dzhandzhal kara? appear identical.