Tesis
Identification and characterization of the powdery mildew (Erysiphe necator) resistance mechanism associated to pyramiding of RUN1 and REN1 resistance loci in table grape (Vitis vinifera) genotypes, developed by conventional breeding.
Autor
Arce Johnson, Patricio
PONTIFICIA UNIVERSIDAD CATOLICA DE CHILE
Institución
Resumen
Fungal pathogens are among the most common diseases affecting grapevine. Powdery mildew, caused by the biotrophic fungus E. necator, is one of the most prevalent diseases affecting grape production worldwide. Different strategies for introgression of resistant (R) genes are currently used in breeding programs. However, recently, breakdown of some fungal resistance have been reported and thus, preventive strategies are necessary for R genes deployment. Taking this into account, we cross-pollinated grapevine plants carrying both RUN1 (Resistance to Uncinula necator 1) and REN1 (Resistance to Erysiphe necator 1) pyramided loci with the table grape cultivars 'Crimson Seedless' and 'Red Globe' and developed RUN1REN1 resistant genotypes. Our results reveal that plants carrying both RUN1 and REN1 pyramided loci display a strong and effective defense response against E. necator since early infection stages, leading to decreased conidia germination and poor hyphae development. This resistance mechanism includes ROS production, callose accumulation, PCD induction and VvSTS36 induction. Grapevine plants developed in this work have a great potential as new table grape cultivars with durable complete resistance to E. necator, hence they can greatly reduce chemical fungicide input, productive costs and environmental impact. Also, they constitute valuable germoplasm to be included in grape breeding programs.