Correlation between agronomic performance and resistance gene in PIWi varieties in the field

Malolactic fermentation (MLF)¹, the decarboxylation of L-malic acid into L-lactic acid, is performed by lactic acid bacteria (LAB). MLF has a deacidifying effect that may compromise freshness or microbiological stability in wines² and can be inhibited by fumaric acid [E297] (FA). In wine, can be added at a maximum allowable dose of 0.6 g/L³. Its inhibition with FA is being studied as an alternative strategy to minimize added doses of SO₂⁴. In addition, wine yeasts are capable of metabolizing and storing small amounts of FA and during alcoholic fermentation (AF).

The objective this work has been study the possibility of partially or completely replacing sulphur in the winemaking of white wines through the use of the prefermentative saturation of musts with CO2.

Context description and research question: an increasing number of farmers are considering the impact of conservation practices on soil health to guide sustainable management of vineyards. Understanding impacts of soil management on soil organic carbon (SOC) is one lever for adoption of agroecological practice with potential to help maintain or improve soil health while building SOC stocks to mitigate climate change (Amelung et al., 2020).

A natural glycolipid mixture obtained from the edible mushroom dacryopinax spathularia (“glycolipids”) is known to be an effective and approved antimicrobial treatment in non-alcoholic beverages at concentrations ranging from 5 – 100 mg/l. It has found a place alongside DMDC for the provision of microbial stability in soft drinks. These properties make the natural and sustainably produced glycolipids a promising candidate for the supplementation or replacement of SO2 in different winemaking processes.

The French grapevine breeding program for durable resistance to downy and powdery mildew (INRAE-ResDur) was initiated more than 20 years ago to help reduce the heavy use of plant protection products and provide a durable mean to cope with a strong pathogen pressure. This program has now proved to be effective, with about ten new varieties already officially registered. However, there is still a lot to be done (1) to reduce the duration of each breeding cycle, (2) to diversify disease factors’ pyramiding and anticipate emerging diseases, (3) to work towards larger adoption of the new resistant varieties. New breeding schemes incorporating for example genomic prediction of breeding values are being evaluated to accelerate genetic gains, saving cost and time while handling complex traits.