conference schedule and program with abstracts - Horticulture ...

P-10
Usefulness of the SCC8 scar marker linked to seedlessness in fungus resistant table grape
breeding
T. Deák* 1 , S. Hoffmann 2 , P. Bodor 1 , F. Kerényi 1 , G.D. Bisztray 1 , P. Kozma 2
1 Department of Viticulture, Institute of Viticulture and Oenology, Corvinus University of
Budapest, Hungary; 2 Institute of Viticulture and Oenology, University of Pécs, Hungary
*Corresponding author: tamas.deak@uni-corvinus.hu
Resistant table grape cultivars without compromises in quality and resistance would be very
advantageous for consumers. As table grape resistance sources are very limited, hybrids with
pure wine grape ancestors need to be used. As in seeded × seedless crosses the proportion of
seedless individuals is low, early selection by MAS is of great importance. In this study the cross
of the Run1 and Rpv1 containing VRH 3082-1-42 (M. rotundifolia × V. vinifera BC 4 ) and the
'Kishmish moldvaskii' seedless table grape has been used to investigate the usefulness of SSC8
marker for MAS. The SCC8 SCAR-CAPS marker can be used to predict stenospermocarpic
seedlessness, however, the SCC8 genotypes of the parents were unknown. 78 progenies of the
VRH 3082-1-42 × ‘Kishmish moldavskii’ cross have been tested for their SCC8 genotypes.
'Kishmish moldavskii' transmitted its seedless phenotype to 44 individuals, which confirms the
presence of a dominant SdI locus responsible for seedlessness. All phenotypes with any kind of
disturbance in seed development have been considered seedless. The SCC8 marker results were
consistent with the progeny phenotypes, we couldn’t identify any recombinants. Although the
seeded parent VRH 3082-1-42 (BC4) showed unusual genotype (SCC8 + /0), the genotyping of
the population could be carried out due to the optimal codominant genotype of the seedless
parent. We tried to trace back the haplotypes of the resistance donor parent VRH 3082-1-42 to be
able to use the SCC8 marker for MAS in other crosses of VRH 3082-1-42. The SCC8 alleles of
the parents have been sequenced. Based on the allele sequences it can be concluded that the
dominant, seedlessness-linked SCC8 + allele of the seeded VRH 3082-1-42 has to be considered
as recombinant and the dominant feature of the allele is not caused by a single point mutation. To
investigate the 0 allele on the other haplotype, four new primers were designed to the consensus
sequences of the alleles, but the amplification of the allele remained impossible. Based on this,
the presence of a null allele could be explained by larger DNA rearrangements instead of
mutations in the priming sites.
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