Using remotely sensed (UAV) and in situ field measurements to describe grapevine canopy characteristics

The aim of this work was to analyze the phenology variability of Tempranillo and Chardonnay cultivars, related to the climatic characteristics in La Mancha Designation of Origin, and their potential changes under climate change scenarios. Phenological dates referred to budbreak, flowering, veraison and harvest were analyzed for the period 2000-2019. The weather conditions at daily time scale, recorded during the same period, were also evaluated. The thermal requirements to reach each of these phenological stages were calculated and expressed as the GDD accumulated from DOY=60. Changes in phenology were projected by 2050 and 2070 taking into account those values and the projected temperatures and precipitation, simulated under two Representative Concentration Pathway (RCP) scenarios –RCP4.5 and RCP8.5– using an ensemble of models. The average phenological dates during the period under study were, April 16th ± 6.6 days and April 5th ± 6.0 days for budbreak, May 31st ± 6.0 days and May 27th ± 5.3 days for flowering, July 26th ± 5.6 days and July 25th ± 5.8 days for veraison, and Ago 23rd ± 10.8 days and Ago 17th ± 9.0 days for harvest, respectively, for Tempranillo and Chardonnay. The projected changes in temperature imply an average change in the maximum growing season (April-August) temperatures of 1.2 and 1.9°C by 2050, and 1.6 and 2.6°C by 2070, under the RCP4.5 and RCP8.5 scenarios, respectively. A reduction in precipitation is predicted, which vary between 15% for 2050 under RCP4.5 scenario and up to 30% by 2070 under RCP8.5. The advance of the phenological dates for 2050, could be of 6, 7, 7, and 8 days for Tempranillo and 4, 6, 6 and 9 days for Chardonnay, respectively for budbreak, flowering, veraison and harvest under the RCP4.5 scenario. Under the RCP8.5 emission scenario, the advance could be up to 30% higher.

Non-Saccharomyces starter cultures became increasingly popular over the years because of their potential to produce more distinctive and unique wines. The major benefit of the use of Lachancea thermotolerans as a fermentation starter is its ability to produce relevant amounts of lactic acid and reduce alcoholic strength, making it valuable for mitigating negative impacts of climate change on grapes and wine quality. Besides, like any other non-Saccharomyces yeast, L. thermotolerans can significantly affect a whole range of other physico-chemical wine parameters.

In this video recording of the IVES science meeting 2021, Sophie Tempère (Institut des Sciences de la Vigne et du Vin – ISVV, Université de Bordeaux) speaks about the recovery of olfactory capacity following a COVID-19 infection. This presentation is based on an original article accessible for free on IVES Technical Reviews.

Mint aromas in wine, which manifest as “cool” or “fresh” character, can originate from different chemical classes, one of which is the terpenoids. A broadly diverse, naturally occurring class of chemical compounds, terpenes possess wide applications across multiple industries due to their pharmaceutical, antiseptic, medical, and aromatic properties. Monoterpenes, a subclass of terpenoids, likewise play a major role in wine sensory perception. Within the monoterpenes, those possessing “mint” odor qualities have often been studied in the context of “vegetal” or “herbal” wine faults; however, their role in positive aromatic evolution is less understood. Yet an extensive 2015 study of older premium Bordeaux red wines identified mint as a contributing factor in quality bouquet development. From that point, it was necessary to investigate the origins of those monoterpenes as well as the chemical conditions required for their development during ageing. Those two key points could finally facilitate predicting the apparition of minty character in older wines based on their composition while young.
A principal contributor is the cyclic monoterpene limonene, which was isolated relatively early in grapes and wine. Not only does limonene itself possess a cool, fresh odor, it is also a precursor for, and possible derivative of, additional mint monoterpenes. Among the most commonly found monoterpenes, limonene and its derivatives can constitute the majority of the essential oils of citrus fruits, mint and herb plants, and coniferous trees. Many of these mint monoterpenes also occur in grapes and wine. With aromas ranging from woody and earthy to citrus to mint and herbaceous, their contribution to wine is potentially diverse and multi-faceted. While sometimes, found at concentrations below the sensory threshold, synergistic effects between these molecules could render them perceivable.
This review looks at limonene and its transformation as studied in different matrices, and potential parallels or analogues in wine. Moreover, within the complex kinetics of wine aging, the relative concentrations of mint monoterpenes appears to continue to evolve and change, with additional evidence from model wine solutions suggesting they may even revert to their originating precursors. Continued study of mint monoterpenes and their role in wine aromatics will contribute to a deeper understanding of the development of aging bouquet and the longevity of premium wines.

Haplotype-resolved genome assemblies were produced for Chasselas and Ugni Blanc, two heterozygous real-field genetic pool Vitis vinifera cultivars by combining high-fidelity long-read sequencing (HiFi) and high‐throughput chromosome conformation capture (Hi-C). The telomere-to-telomere full coverage of the chromosomes allowed us to assemble separately the two haplo-genomes of both cultivars and revealed structural variations between the two haplotypes of a given cultivar.