Genetic characterization of different Vitis species using SSR markers associated with the resistance gene PdR1

Pierce's disease caused by the bacteria Xylella fastidiosa affects several crops including grapevine. Regarding bibliographic references, several molecular markers associated with the PdR1 gene for resistance to X. fastidiosa have been described in the specie Vitis arizonica. Six microsatellite markers (Short Sequence Repeats, SSR) flanking the PdR1 gene were selected for evaluation in a large set of grapevine varieties from different national sources and compared with the tolerant variety. The plant material selected for the study includes American, vinifera and wild species no tested so far. SSRs analysis showed that allelic patterns obtained between presumably susceptible varieties and the tolerant V. arizonica variety differed. Subsequent principal component analysis (PCA) showed clusters defined at the species level but not at the varietal level. It is also observed that the V. arizonica variety tested shows an allelic pattern of heterozygosity similar to the resistant variety described in the literature. Knowing the susceptibility of the vinifera, we corroborate this trend in new varieties relevant to wine growing in the Basque Country as well as for other known materials. This study will be complemented with the evaluation of the varietal response to infection at phenotypic and molecular level.ES; PDF; smartinez@neiker.eu