Rootstock-scion contributions to seasonal water and light use diversity under field conditions

Grapevines have traditionally been grown in semi-arid areas, but viticulture is now compromised by climate change. Therefore, it is necessary to implement environmentally friendly viticulture practices to adapt grapevines to current climatic conditions. In this context, organic mulches offer many benefits, such as reduced soil erosion and increased organic matter, soil water content and crop productivity. However, these practices must not compromise grape and wine quality. Therefore, the objective of this study was to evaluate the effect on wine physicochemical and phenolic composition and sensorial properties of different soil management practices on the vine row. Over four years, five soil treatments were examined in two different vineyards.

Lo studio è stato condotto in vigneti commerciali di Vitis vinifera cv Nebbiolo localizzati in Piemonte, Italia del Nord-Ovest, intorno alla sommità di una collina. L’obiettivo dello studio è stato di determinare come l’esposizione del vigneto possa influenzare il comportamento vegetativo della vite, il manifestarsi delle fasi fenologiche, e la cinetica di maturazione dell’uva con particolare riguardo all’accumulo di antociani e flavonoli.

Climate change is here. One of the main consequences is an increase in the frequency and severity of abiotic stresses which mostly occur in a combined manner. Grapevine, which grows in a large diversity of pedo-climatic conditions, has presumably evolved different mechanisms to allow this widespread adaptation. Harnessing the genetic diversity in these mechanisms will be central to the future of viticulture in many traditional wine growing areas. The interactions between the scion and the rootstock through grafting add an additional level of diversity and adaptive potential to explore.
At the physiological level, these mechanisms are related to processes such as root system development and functioning (water and nutrient uptake), interactions with the soil microbiome, gas exchange regulation, hydraulic properties along the soil-plant-atmosphere continuum, reserve storage, short and long distance signaling mechanisms and plasticity for some of these traits.

In table grapes seedlessness is a crucial breeding target, mainly results from stenospermocarpy, linked to the Thompson Seedless variety. Several studies investigated the genetic control of seedlessness identifying AGL11, a MADS-box transcription factor, as a crucial gene.
We performed a deep investigation of the whole AGL11 gene sequence in a collection of grapevine varieties revealing three different promoter-CDS combinations. By investigating the expression of the three AGL11 alleles and evaluating their ability to activate the promoter region, we show that AGL11 regulates its transcription in a specific promoter-CDS manner. By a multi-AGL11 co-expression analysis we identified a methyl jasmonate esterase, an indole-3-acetate beta-glucosyltransferase, and an isoflavone reductase as top AGL11 candidate targets. In vivo experiments further confirmed AGL11 role in regulating these genes, demonstrating its significant influence in seed development and thus in seedlessness trait.

Cabernet Sauvignon grapes from recently planted vines in Santa Catarina State (Brazil), were sampled during ripening from the 2005 and 2006 vintages.