Resumen de Sequencing of the phylloxera resistance locus rdv1 of cultivar 'börner'
Ludger Hausmann, R. Eibach, Eva Zyprian, Reinhard Töpfer
Cultivar ?Börner?, an interspecific cross of Vitis riparia Gm 183 and V. cinerea Arnold, is a phylloxera root resistant rootstock showing neither tuberosity nor nodosity symptoms. The Rdv1 locus, a major quantitative trait locus (QTL) localized on chromosome 13, correlates with the resistance phenotype. In order to identify the responsible gene(s) for this trait a high density genetic map was established for this region deducing STS markers from the V. vinifera genome sequence. For physical mapping a bacterial artificial chromosome (BAC) library was screened with the STS markers of the Rdv1 locus. The isolated clones were used to build up a minimal tiling path for the V. cinerea haplotype covering almost the entire locus. The BACs were sequenced, contigs assembled and finishing accomplished using the PN40024 genome sequence as a reference. Small final gaps were closed by sequencing of PCR products. Comparison of the 350 kb Rdv1 sequence with the V. vinifera sequence of PN40024 revealed a conserved gene order even for the small RGA cluster located in the middle of the sequence of both genomes. However, between these RGA clusters a low sequence homology and larger structural rearrangements within the RGAs and repetitive transposon fragments were observed. Therefore, the NBS-LRR-like genes located in the RGA cluster of the Rdv1 locus are favourable candidate genes for the phylloxera resistance of rootstock ?Börner?.
