Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

The main objective of the work was to develop a simple, robust and selective analytical tool that allows predicting the authenticity of Tempranillo wines from DOCa Rioja. The techniques of voltammetry and absorbance-transmission and fluorescence excitation emission matrix (A-TEEM) spectroscopy have been applied in combination with machine learning (ML) algorithms to classify red wines from DOCa Rioja according to region (Alavesa, Alta or Oriental) and category (young, crianza or reserva).

The seminar will examine the complexities and prospects of genomic research on Vitis species, characterize by exceptionally high heterozygosity and common interspecific gene flow. The seminar will showcase case studies highlighting the critical role of diploid genome references in grape research, specifically in areas such as aroma development, disease resistance, and domestication traits. It will also address the emerging focus on pangenomes within the Vitis genus, particularly in the context of genetic studies on naturally interbreeding populations.

The nitrogen composition of the grapes directly affects the developments of alcoholic fermentation and influences the final aromatic composition of the wines. The aim of this study was to determine the effect and efficiency of foliar applications of urea on the nitrogen composition of grapes. This study was carried out during 2023 vintage and in the Chenin vineyard located in Estacion Experimental Mendoza (Argentina). Three urea concentrations 3, 6 and 9 Kg N/ha (C1, C2, and C3, respectively) and control (T) were applied in this vineyard at veraison. In all solutions were added 1ml/l of Tween 80 ® surfactant.

The vineyard has experienced a general increase in yields mainly due to the elevated use of technology which caused a quality loss of grapes in more than one case. A large percentage of the Spanish vineyard is covered by a Denomination of Origin which limits the productive level of the vineyards as one of its regulations. The maximum production limit is a variable characteristic of each vineyard and is not usually regulated by agronomic criteria, and this explains the fact that each vineyard can reach high quality with a totally different yield from that set by the Denomination of Origin.

Global warming and increased frequency and/or severity of drought events are among the most threatening consequences of climate change for agricultural crops. In response to drought, grapevine (as many other plants) exhibits osmotic adjustment through active accumulation of osmolytes which in turn shift the leaf turgor loss point (TLP) to more negative values, allowing to maintain stomata opened at lower water potentials1. We investigated the capacity of Pinot noir leaves to modulate their osmotic potential as a function of: (i) time (seasonal osmoregulation), (ii) growing temperatures, and (iii) drought events, to enhance comprehension of the resilience of grapevines in drought conditions. We performed trails under semi-controlled field conditions, and in two different greenhouse chambers (20/15 °C vs 25/20 °C day/night). For two consecutive vegetative seasons, grafted potted grapevines (Pinot noir/SO4) were subjected to two different water regimes for at least 30 days: well-watered (WW) and water deficit (WD).