Phased T2T genome assemblies facilitate the mining of disease-resistance genes in Vitis davidii

Abstract

Grape is an important fruit crop, and its production faces significant threat from diseases, resulting in substantial economic loss. Wild grape relatives are valuable resources for the restoration of disease-resistance loci. However, available resistance loci in wild grape genomes remain largely unexplored. In this study, we assembled two phased genomes, including a high resistant Chinese wild grape, Vitis davidii Föex, and a susceptible cultivar, V. vinifera L. cv. “Manicure Finger”. We detected a total of 36,688 structural variations (SVs), with the genes associated with heterozygous SVs showing an enrichment in allele-specific expression (ASE). Furthermore, we identified eight subgroups of R genes and found that 74.2% of R genes overlap with transposable elements (TEs). Among R genes, NBS-type genes exhibit higher expression profiles in the wild grape genome compared with those in the grape cultivar. Additionally, five specific NBS-type R gene clusters were identified in the wild grape genome that are absent in the cultivar. Through genetic mapping, we identified four quantitative trait loci (QTLs) associated with grape white rot resistance based on the Vitis davidii genome, within which six NBS-type R genes exhibit differential expression between wild and cultivated grapes. Overall, our study revealed the landscape of resistance genes in grape genomes, providing valuable genetic resources for further breeding programs.