Influence of grapevine rootstock/scion combination on rhizosphere and root endophytic microbiomes

En Anjou, une méthode de caractérisation des terroirs viticoles a été développée. Elle utilise un modèle de terrain basé sur la profondeur de sol et son degré d’argilisation.

Grapevine (Vitis Vinifera L.), one of the most important cultivated fruit crops, is facing significant challenges due to climate change. Specifically, increasing temperatures negatively impact the physiological traits and disrupt plant phenology. Additionally, increased virulence in pathogen attacks and pests leads to significant yield loss, requiring widespread application of plant protection products. Traditional agronomic practices offer only partial mitigation, requiring the development of precise and effective intervention strategies. The economic worth of viticulture has prompted continuous efforts in grapevine genetic improvement programs, traditionally involving conventional breeding and clonal selection that, however, are complex and time-consuming approaches.

The use of new fungus disease-tolerant varieties is a promising long-term solution to better manage chemical input in viticulture, but unfortunately little is known regarding these new hybrids fruit development and metabolites accumulation in front of abiotic stresses such as water deficit (WD). Thus, prior to the adoption of such varieties by the wine industry in Mediterranean regions, there is a need to consider their suitability to WD.

Grapevine breeding is part of the research program of Agroscope in Switzerland since 1965. From 1965 to 1995, the aim of the Vitis vinifera crosses was to obtain a high resistance to grey rot (Botrytis cinerea), one of the most virulent fungal pathogens in the Swiss vineyard. In 2021, the grape varieties released from this first breeding program covered 936 ha of the 15’000 ha of the Swiss vineyard.
In 1996, a second breeding program aimed at obtaining, by classical interspecific hybridization, grape varieties resistant to downy mildew (Plasmopara viticola) and powdery mildew (Erisyphe necator) and less sensitive to grey rot (Botrytis cinerea). In order to accelerate and make the selection process more reliable, an early biochemical test was developed based on the natural defense mechanisms of the vine against downy mildew (stilbene phytoalexins). The synthesis of stilbenes (i.e., resveratrol and its oxidized dimers - and -viniférine) and pterostilbenes (methylated derivative) is among the most efficient induced defense mechanisms of grapevine against fungal pathogens on both the leaves and the clusters.

Aim: To investigate the interaction effects between irrigation and crop load and the resulting impact on grape heterogeneity within a Geographical Indication in South Australia. 

Methods and Results: Cabernet Sauvignon grapes were sampled at the time of harvest from the Coonawarra