Fecha de publicación: 06/01/2024 Fuente: ISHS (International Society for Horticultural Science) Post date: Saturday 6 January 2024
Author:
ISHS Secretariat

The employment of Vitis vinifera germplasm for the development of downy mildew resistant cultivars could greatly shorten and simplify breeding programs. ‘Mgaloblishvili’ is a V. vinifera cultivar that has shown some resistance to grape downy mildew (Plasmopara viticola), one of the most destructive diseases affecting grapevines. A genome wide association study was able to identify three new loci associated with the ‘Mgaloblishvili’ resistant phenotype: Rpv29, Rpv30 and Rpv31. Nonetheless, the protein-coding genes responsible for the resistance remain elusive. To address this gap, the ‘Mgaloblishvili’ genome was sequenced and assembled using PacBio HiFi reads. The obtained chromosome-level diploid genome (986 Mb) was used to identify the target loci, which were successfully characterized for their gene content and expression after infection with P. viticola. The genome structure of the regions of interest was analyzed comparing ‘Mgaloblishvili’ haplotypes to the grapevine reference genome PN40024. Furthermore, using DNA sequencing data of two resistant and two susceptible accessions from ‘Mgaloblishvili’ self-cross progeny, Rpv30 and Rpv31 resistance haplotypes were successfully identified. These findings will increase our knowledge about the downy mildew grapevine pathosystem. Moreover, they will accelerate the potential employment of these valuable traits for the development of elite cultivars with durable resistance to downy mildew. Valentina Ricciardi is a PhD student at the Department of Agricultural and Environmental Sciences, University of Milan, Italy, where she is studying the identification of grapevine genetic resources to be used in breeding programs for the improvement of viticultural practices.
Valentina Ricciardi won the ISHS Young Minds Award for the best oral presentation at the XIII International Conference on Grapevine Breeding, Genetics and Management in Turkey in August 2023.
Valentina Ricciardi, Department of Agricultural and Environmental Sciences, University of Milan, Via Celoria 2, 20133 Milan, Italy, e-mail: valentina.ricciardi@unimi.it
The article is available in Chronica HorticulturaeTags: grapevine downy mildewCategories: Young Minds Award Winners