terclim by ICS banner
IVES 9 IVES Conference Series 9 Mgaloblishvili Rpv29 and Rpv31 loci reveal new insights on downy mildew resistance sources in Vitis vinifera

Mgaloblishvili Rpv29 and Rpv31 loci reveal new insights on downy mildew resistance sources in Vitis vinifera

Abstract

Downy mildew, a disease caused by Plasmopara viticola (Berk. et Curt.) Berl. and De Toni, is one of the strongest threats to grapevine (Vitis vinifera L.) production. Recently, sources of resistance to downy mildew were identified among Caucasian germplasm. Among them, the Georgian variety Mgaloblishvili revealed a unique resistance mechanism. A genome wide association study (GWAS) allowed the identification of the genetic bases of Mgaloblishvili resistance, the loci Rpv29, Rpv30 and Rpv31. To dissect the three resistance loci, Mgaloblishvili genome was sequenced using PacBio HiFi reads and assembled. A chromosome-scale diploid genome assembly consisting of ~ 986 Mb and a contig N50 length of 25.8 Mb was obtained. A total of 58,912 protein-coding genes were predicted on the two sets of phased chromosomes. A whole genome comparison with the genome of the susceptible reference accession PN40024 was performed. Mgaloblishvili resistance loci were in-depth analyzed in terms of structure, gene content, gene expression and impact of structural variants (SVs) and SNPs (Single Nucleotide Polymorphisms). Furthermore, using DNA sequencing data of Mgaloblishvili self-cross progeny, resistance haplotypes were identified for Rpv30 and Rpv31. The obtained data highlighted Mgaloblishvili resistant phenotype as a consequence of multiple small SVs and SNPs, that eventually results into differential transcriptional regulation. Altogether, these genetic resources will increase the knowledge about downy mildew-grapevine pathosystem. Moreover, they will be available for breeding programs aiming to develop grapevine resistant varieties.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Article

Authors

Valentina Ricciardi 1, Andrea Minio 2, Melanie Massonnet 2, Alexander H.J. Wittenberg3, David Maghradze 4,5,6, Silvia Laura Toffolatti 1, Osvaldo Failla 1, Dario Cantù 2*, Gabriella De Lorenzis

1 Department of Agricultural and Environmental Sciences, University of Milan
2 Department of Viticulture and Enology, University of California, Davis (CA), USA
3 KeyGene, Wageningen, The Netherlands
4 Caucasus International University, Tbilisi, Georgia
5 Georgian Technical University, Tbilisi, Georgia
6National Wine Agency of Georgia, Tbilisi, Georgia

Contact the author*

Keywords

Grapevine, biotic stress, QTL, genome, Caucasus

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Climate change and viticulture in Nordic Countries and the Helsinki area

The first vineyards in Northern Europe were in Denmark in the 15th century, in the southern parts of Sweden and Finland in the 18th century at 55–60 degrees latitude. The grapes grown there have not been made into wine, but the grapes have been eaten at festive tables. The resurgence of viticulture has started with global warming, and currently the total area of viticulture in the Nordic countries, including Norway, is estimated to be 400–500 hectares, most of which is in Denmark. Southern Finland, like all southern parts of Northern Europe, belongs to the cool-cold winegrowing area.

Towards stopping pesticides: survey identification of on-farm solutions

The winegrowing sector consumes a lot of pesticides. Changes in vineyard are necessary in order to reduce or even stop using pesticides, and thus limit their harmful impacts on health and on environment. To answer these issues, the VITAE project (2021-2026) aims at designing pesticide free grapevine systems in France. For that, we take an interest in the vineyards using solutions to strongly reduce chemicals but also biopesticides. We assume that such vineyards exist and that they are implementing solutions that could inspire the design of free- pesticide system.

Astringency subqualities and the sensory-chemical drivers of wine typicality: A study on Nebbiolo wines

Typicality is a multidimensional concept resulting from the interplay of intrinsic and extrinsic characteristics.

Characterization of vine vigor by ground based NDVI measurements

Many farming operations aim at controlling the leaf area of the vine according to its load. There are several techniques, direct and indirect, of estimate of this leaf area in a specific way, but impossible to implement at great scales. These last years, research in airborne and satellite remote sensing made it possible to show that a multispectral index of vegetation, computed from measurements of reflectances (red and near infrared), the « Normalised Difference Vegetation Index » (NDVI), is well correlated to the « Leaf Area Index » (leaf area per unit of ground) of the vine. Nevertheless these methods of acquisition and processing data are rather constraining and complex.

Drought affects vineyard soil microbiome: approach to select micro-organisms adapted to drought

Climate transition with frequent heat waves and long drought periods threatens grapevine productivity and wine quality in the Mediterranean regions. Microorganisms are known to contribute to plant fitness and to stimulate plant resilience against biotic and abiotic factors.
In this work, it was assessed the impact of long-term drought on soil microbiome associated to grapevine in open field in Alentejo, renowned Portuguese wine region.
Soil and plant tissues of drought tolerant Syrah cultivar exposed to three irrigation levels (100%- FI, 50%-DI ETc; rain-fed–NI) for 5 years were sampled for two years (2022-2023). Metabarcoding analysis of soil bacteria (16S V4 rRNA) and fungi (ITS sub-region) were integrated with soil physiochemical properties and leaves´ physiological data. Pre-dawn leaf water potential and stomatal conductance confirmed the imposed drought scenarios. Even though, α- and β-diversity of prokaryotic and eukaryotic microbial communities differed more by season than water availability, samples clustered according to soil water content and pH (p<0.05). Fungal communities show higher differences in the structure across treatments than bacteria. In 2023, 16 bacterial against 61 fungal ASVs were significatively different in abundance between NI and FI. Beijerinckiaceae, Bradyrhizobiaceae (Alphaproteobacteria) and Nocardioidaceae, Streptomycetaceae (Actinobacteria) families resulted to be significatively more abundant in NI, while Ascomycota, Basidyomicota and Mortierellomycota are the most important fungal phyla in NI. With culturomics data, this study aims to gather insights into how soil microbiome is remodelled under drought and contribute to select bacterial and fungal taxa with potential to mitigate drought stress in vineyards.