Characterization of the adaptive mechanisms of grapevine rootstocks to iron deficiency induced by lime stress

With contemporary climate change, cultivated Vitis vinifera L. is at risk as climate is a critical component in defining ecologically fitted plant materiel. While winegrowers can draw on the rich diversity among grapevine varieties to limit expected impacts (Morales-Castilla et al., 2020), replacing a signature variety that has created a sense of local distinctiveness may lead to several challenges. In order to sustain wine identity in uncertain climate outcomes, the study of intra-varietal diversity is important to reflect the adaptive and evolutionary potential of current cultivated varieties. The aim of this ongoing study is to understand to what extent can intra-varietal diversity be a climate change adaptation solution. With a focus on early (Sauvignon blanc, Riesling, Grolleau, Pinot noir) to moderate late (Chenin, Petit Verdot, Cabernet franc) ripening varieties, data was collected for flowering and veraison for the various studied accessions (from conservatory plots) and clones. For these phenological growing stages, heat requirements were established using nearby weather stations (adapted from the GFV model, Parker et al., 2013) and model performances were verified. Climate change projections were then integrated to predict the future behaviour of the intra-varietal diversity. Study findings highlight the strong phenotypic diversity of studied varieties and the importance of diversification to enhance climate change resilience. While model performances may require improvements, this study is the first step towards quantifying heat requirements of different clones and how they can provide adaptation solutions for winegrowers to sustain local wine identity in a global changing climate. As genetic diversity is an ongoing process through point mutations and epigenetic adaptations, perspective work is to explore clonal data from a wide variety of geographic locations.

Microbial pathogens of plant have evolved to sense, interpret, and use light to direct their development. One aspect of this evolved relationship is photolyase-mediated repair of UV-induced damage to pathogen DNA. Application of germicidal UV (UV-C) at night circumvents the blue light-driven repair of pathogen DNA and allows non-phytotoxic doses of UV-C to suppress a variety of pathogenic microbes and even certain arthropod pests without damage to vines or fruit. Lamps arrays have been designed specifically for the canopy architecture of grapevines and have been deployed on both tractor-drawn and robotic carriages for partial to near-complete suppression of powdery mildew (Erysiphe necator), sour rot (fungal, bacterial, and arthropod complex), and downy mildew (Plasmopara viticola).

Combined improvements in sequencing technologies and assembly algorithms have led to staggering improvements in the quality of grape genome assemblies.

The Appellation d’Origine Contrôlée area of ​​Cahors (Lot) covers an area of ​​21,700 ha, spread over 45 municipalities, of which only 4,300 are planted with vines. The main grape variety of this AOC is the Cot noir which represents 70% of the grape varieties, thus giving their typicality to the wines of this region; but despite this importance, to our knowledge, its physiology has remained relatively unstudied.

AIM: The aim of this work was to characterize 18 oenological tannins by the polyphenolic, antioxidant, and sensory point of view.