Vineyard microclimate alterations induced by black mulch through transcriptome reshaped the flavoromics of Cabernet Sauvignon

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.

In order to disseminate the scientific results presented during the WAC 2022 , the organizers have decided to share the abstracts of the oral communications and posters with Open Access on IVES Conference Series. The fifth edition of the International Conference...

Grapevine cultivars are vegetatively propagated to maintain their varietal attributes. However, spontaneous somatic variation emerges during prolonged periods of vegetative growth, providing an opportunity for the natural improvement of traditional grapevine cultivars. Notably, reduction in bunch compactness is a favorable trait in viticulture, offering advantages such as decreased susceptibility to bunch fungal diseases, and a more uniform ripening of berries. To unravel the genetic and developmental mechanisms behind bunch compactness variation, we examined a somatic variant of Tempranillo Tinto cultivar with loose bunches. We found that the mutant clone exhibits a ~50% reduction in pollen viability compared to typical Tempranillo clones.

As viticulture faces challenges such as climate change or vineyard dieback, the choice of the variety and rootstock becomes more and more crucial. To study rootstock levers in the Bordeaux region, a parcel of Cabernet Sauvignon (CS) was planted with four rootstocks in 2014. Twenty repetitions of each of the following four rootstocks were set up: 101-14 MGt, Nemadex AB, 420A MGt and Gravesac. The number of bunches, yields and pruning weights of the vine shoots were measured individually on 240 vines from 2017 to 2021. Since 2020, nitrogen status assessed by assimilable nitrogen level, hydric status assessed by δ13C and berry maturity were measured on 80 samples taken from 20 repetitions of the four rootstocks. A lower yield was measured for CS grafted onto Nemadex AB due to the lower number of bunches and the lower weight of berries. The differences between the other three rootstocks are small, but CS grafted onto 420A MGt was the most productive. The CS grafted onto Nemadex AB had the lowest pruning weight while 101-14 MGt had the highest. In 2020, δ13C showed a more moderate water stress with 101-14 MGt and 420A MGt than with Nemadex AB. Surprisingly, the Gravesac was under more stress than the 101-14 MGt. The nitrogen status in the berries was better for Nemadex AB but this was perhaps due to the significantly lower weight of the berries.Rootstock 101-14 MGt attained the highest accumulation of sugars in the berries while 420A MGt allows to preserve higher acidity. The parcel is still young which may explain some of the results. These measures must therefore be continued over the next several years to fully assess the effects of these rootstocks on the development of the vines and the quality of the production under new climatic conditions.

In recent years, the increase in temperature and the changes in rainfall distribution caused by climate change are affecting vine and grape physiology and are consequently impacting wine composition and quality (Schultz, 2000; Jones et al., 2005).