Novel loci associated with resistance to downy and powdery mildew in grapevine

Valentina Ricciardi; Manna Crespan; Giuliana Maddalena; Daniele Migliaro; Lucio Brancadoro; David Maghradze; Osvaldo Failla; Silvia Laura Toffolatti; Gabriella De Lorenzis

doi:10.3389/fpls.2024.1386225

Novel loci associated with resistance to downy and powdery mildew in grapevine

Front Plant Sci. 2024 Mar 22:15:1386225. doi: 10.3389/fpls.2024.1386225. eCollection 2024.

Authors

Valentina Ricciardi¹, Manna Crespan², Giuliana Maddalena¹, Daniele Migliaro², Lucio Brancadoro¹, David Maghradze^{3

4}, Osvaldo Failla¹, Silvia Laura Toffolatti¹, Gabriella De Lorenzis¹

Affiliations

¹ Dipartimento di Scienze Agrarie ed Ambientali, Università degli Studi di Milano, Milano, Italy.
² Centro di Ricerca per la Viticoltura e l'Enologia, Consiglio per la ricerca in agricoltura e l'analisi dell'economia agraria (CREA), Conegliano, Italy.
³ Faculty of Viticulture-Winemaking, Caucasus International University, Tbilisi, Georgia.
⁴ Faculty of Agricultural Sciences and Biosystems Engineering, Georgian Technical University, Tbilisi, Georgia.

Abstract

Among the main challenges in current viticulture, there is the increasing demand for sustainability in the protection from fungal diseases, such as downy mildew (DM) and powdery mildew (PM). Breeding disease-resistant grapevine varieties is a key strategy for better managing fungicide inputs. This study explores the diversity of grapevine germplasm (cultivated and wild) from Caucasus and neighboring areas to identify genotypes resistant to DM and PM, based on 13 Simple Sequence Repeat (SSR) loci and phenotypical (artificial pathogen inoculation) analysis, and to identify loci associated with DM and PM resistance, via Genome-Wide Association Analysis (GWAS) on Single Nucleotide Polymorphism (SNP) profiles. SSR analysis revealed resistant alleles for 16 out of 88 genotypes. Phenotypic data identified seven DM and 31 PM resistant genotypes. GWAS identified two new loci associated with DM resistance, located on chromosome 15 and 16 (designated as Rpv36 and Rpv37), and two with PM resistance, located on chromosome 6 and 17 (designated as Ren14 and Ren15). The four novel loci identified genomic regions rich in genes related to biotic stress response, such as genes involved in pathogen recognition, signal transduction and resistance response. This study highlights potential candidate genes associated with resistance to DM and PM, providing valuable insights for breeding programs for resistant varieties. To optimize their utilization, further functional characterization studies are recommended.

Keywords: GWAS; Ren; Rpv; SNP; SSR; candidate genes; phenotyping.

Grants and funding

The author(s) declare financial support was received for the research, authorship, and/or publication of this article. The research was supported by European Union within the project titled “FREECLIMB – Fruit Crops Adaptation To Climate Change In The Mediterranean Basin” in the frame of the Program Partnership For Research And Innovation In The Mediterranean Area (PRIMA) and the project titled “INNOVINE - Combining innovation in vineyard management and genetic diversity for a sustainable European viticulture” (Grant agreement ID: 311775) in the frame of the Specific Programme “Cooperation”: Food, Agriculture and Biotechnology.