Open Access
Obtaining spatial variations in Cabernet Sauvignon (Vitis vinifera L.) wine flavonoid composition and aromatic profiles by studying long-term plant water status in hyper-arid seasons
(MDPI, 2024) Yu, Runze; Torres Molina, Nazareth; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
The spatial variability in vineyard soil might negatively affect wine composition, leading to inhomogeneous flavonoid composition and aromatic profiles. In this study, we investigated the spatial variability in wine chemical composition in a Cabernet Sauvignon (Vitis vinifera L.) vineyard in 2019 and 2020. Because of the tight relationships with soil profiles, mid-day stem water potential integrals (Ψstem Int) were used to delineate the vineyard into two zones, including Zone 1 with relatively higher water stress and Zone 2 with relatively lower water stress. Wine from Zone 2 generally had more anthocyanins in 2019. In 2020, Zone 1 had more anthocyanins and flavonols. Zone 2 had more proanthocyanidin extension and terminal subunits as well as total proanthocyanidins in 2020. According to the Principal Component Analyses (PCA) for berry and wine chemical composition, the two zones were significantly different in the studied wine aromatic compounds. In conclusion, this study provides evidence of the possibility of managing the spatial variability of both wine flavonoid composition and aromatic profiles through connecting vineyard soil variability to grapevine season-long water status.
Open Access
Remote sensing for plant water content monitoring: a review
(MDPI, 2021) Quemada Mayoral, Carlos; Pérez Escudero, José Manuel; Gonzalo García, Ramón; Ederra Urzainqui, Íñigo; Santesteban García, Gonzaga; Torres Molina, Nazareth; Iriarte Galarregui, Juan Carlos; Institute of Smart Cities - ISC; Institute for Multidisciplinary Research in Applied Biology - IMAB
Las redes sociales se han convertido en una de las principales fuentes de información, especialmente entre los más jóvenes. Al mismo tiempo, se ha incrementado la producción y circulación de información falsa o fake news a través de las redes. En este contexto, resulta crucial que los jóvenes adquieran estrategias y competencias para realizar una lectura crítica de la información que consumen. Este estudio busca analizar el comportamiento del alumnado de secundaria ante la información falsa y el efecto de una intervención didáctica, realizada online durante la pandemia de la covid-19, cuyo objetivo era que el alumnado desarrollara competencias para detectar noticias falsas. Se trata de una investigación participativa con un diseño de pre-test y post-test. Los resultados muestran que el alumnado incrementó su competencia para identificar algunos tipos de falsedad como la información no probada y la información tergiversada, si bien tuvo problemas para reconocer información descontextualizada o el uso de lenguaje discriminatorio. Las estrategias que más utilizó son la comprobación de datos en internet y el uso de verificadores. Se observaron comportamientos diferenciados entre el alumnado que identificó la información falsa y el que no lo hizo. Las conclusiones apuntan a la necesidad de trabajar en el aula de forma integral, extensiva y transversal la evaluación de la información partiendo de las habilidades que el alumnado ya posee.
Open Access
Inoculation with mycorrhizal fungi and irrigation management shaped the bacterial and fungal communities and networks in vineyard soils
(MDPI, 2021) Torres Molina, Nazareth; Yu, Runze; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Vineyard-living microbiota affect grapevine health and adaptation to changing environments and determine the biological quality of soils that strongly influence wine quality. However, their abundance and interactions may be affected by vineyard management. The present study was conducted to assess whether the vineyard soil microbiome was altered by the use of biostimulants (arbuscular mycorrhizal fungi (AMF) inoculation vs. non-inoculated) and/or irrigation management (fully irrigated vs. half irrigated). Bacterial and fungal communities in vineyard soils were shaped by both time course and soil management (i.e., the use of biostimulants and irrigation). Regarding alpha diversity, fungal communities were more responsive to treatments, whereas changes in beta diversity were mainly recorded in the bacterial communities. Edaphic factors rarely influence bacterial and fungal communities. Microbial network analyses suggested that the bacterial associations were weaker than the fungal ones under half irrigation and that the inoculation with AMF led to the increase in positive associations between vineyard-soil-living microbes. Altogether, the results highlight the need for more studies on the effect of management practices, especially the addition of AMF on cropping systems, to fully understand the factors that drive their variability, strengthen beneficial microbial networks, and achieve better soil quality, which will improve crop performance.
Open Access
Source-sink manipulation does not mitigate the effects of grapevine red blotch virus (GRBV) infection on fruit sugar and flavonoid accumulation in Cabernet-Sauvignon
(International Viticulture and Enlogy Society, 2023) Kurtural, Sahap Kaan; Tanner, Justin D.; Mainos, Dimitirios; Yu, Runze; Torres Molina, Nazareth; Martínez-Lüscher, Johann; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Grapevine red blotch virus (GRBV) negatively affects the composition of grapevine (Vitis vinifera L.) berries by reducing total soluble solids and anthocyanins, leading to economic losses for grape producers. Negative effects of GRBV were suspected to be due to impeded carbon translocation from leaves to fruit which limits sugar and flavonoid accumulation in berries. A two-year trial was conducted to determine whether an increase in source: sink ratio may affect sugar allocation and mitigate the effects of GRBV on Cabernet-Sauvignon plants. Experimental design was factorial (2 by 2) with healthy plants that did not have the virus (GRBV (-)) and plants having GRBV (GRBV (+)) and plants were subjected either untreated (UNT) or cluster thinned down to 10 clusters (CT). Effects of cluster thinning and virus status on leaf and shoot total soluble sugars (TSS), plant water status, leaf gas exchange, berry primary and secondary metabolites, and yield components were measured. The TSS in leaves began to accumulate around véraison. In shoot sap, GRBV(-) plants had greater concentration in TSS than GRBV(+) plants. The presence of disease improved plant water status increasing the stem water potential and increasing berry mass. However, juice total soluble solids were consistently lower in GRBV(+) plants despite increasing source: sink ratio by 3× with cluster removal. Likewise, GRBV(+) plants produced berries with lower anthocyanin content at harvest regardless of CT in both years. Our results suggest that GRBV infection severally impeded carbohydrate translocation out of the leaves, and in contrast to healthy plants reducing the number of clusters does not induce a reconcentration of sugars in the remaining clusters.
Open Access
Timing of defoliation affects anthocyanin and sugar decoupling in Grenache variety growing in warm seasons
(Elsevier, 2024) Fernández-Zurbano, Purificación; Santesteban García, Gonzaga; Villa Llop, Ana; Loidi Erviti, Maite; Peñalosa, Carlos; Músquiz, Sergio; Torres Molina, Nazareth; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa
Warming trends over the winegrowing regions lead to an advance of grapevine phenology, decreased yield and increased sugar content with a lower polyphenol content. We hypothesized that different leaf removal timings may counteract these effects. A two-year experiment was conducted in La Rioja (Spain) with Vitis vinifera L. cv. Grenache trained in an open-vase system. Trial consisted in a complete block design with two leaf removal treatments differing in the moment of manipulation: i) severe leaf removal treatment conducted after fruit set (ELR); and ii) severe leaf removal at veraison (LLR) compared to an untreated control (Control). Both leaf removal treatments tended to decrease sugar content with no effect on yield, these effects being highly affected by the year. Defoliation accounted for a decreased flavanol and stilbene contents in berries at harvest. An ELR increased anthocyanin and phenolic acid contents at harvest, while warming during 2022 accounted for decreased contents of all the monitored groups of flavonols. ELR was only effective for delaying ripening by means of impairing the sugar:anthocyanin decoupling during the 2021 growing season which was related to lower % of kaempferol. Altogether, results suggested that defoliation should still be applied under currently warming trends in some viticulture regions.
Open Access
Shifts in phenolic composition and aromatic profiles of Cabernet Sauvignon (vitis vinifera L.) wines are driven by different irrigation amounts in a hot climate
(Elsevier, 2021) Torres Molina, Nazareth; Yu, Runze; Martínez-Lüscher, Johann; Girardello, Raul C.; Kostaki, Evmorfia; Oberholster, Anita; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Wine final color, taste and aroma are closely related to the accumulation of secondary metabolites that may be affected by deficit irrigation applied in viticulture. A two-year study was conducted to assess the different fractions of crop evapotranspiration (ETc) irrigation replacement on wine composition, addressing the analysis of flavonoids and volatiles under context of global warming. Irrigating with 100% ETc (full grapevine demand) enhanced wine hue, antioxidant capacity, and some aromas; however, it came with a diminution of flavonoids and a less stable flavonoid profile. Replacing 25 and 50% ETc in wine grape improved wine color intensity, concentration of flavonoids, and shifted the aromatic profiles. These treatments increased some terpenes and esters which may enhance the desirable aromas for Cabernet Sauvignon, and decreased C6 alcohols related to unpleasant ones. Therefore, despite the warming trends in Mediterranean climates, 100% ETc irrigation would be not advisable to improve or maintain wine quality, and 50% ETc was sufficient.
Open Access
Conventional and newly bred rootstock effects on the ecophysiological response of Vitis vinifera L. cv. Tempranillo
(Elsevier, 2023) Buesa, Ignacio; Torres Molina, Nazareth; Tortosa, Ignacio; Marín Ederra, Diana; Villa Llop, Ana; Douthe, Cyril; Santesteban García, Gonzaga; Medrano, H.; Escalona, José M.; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Achieving more environmentally sustainable vineyards, particularly regarding efficient water use, is paramount in semi-arid grape-growing regions. Rootstocks may be a possible strategy to address these challenges, but require a comprehensive evaluation of their effect on the scion, including ecophysiological traits. The objectives of this study were 1) to characterize the physiological response of Tempranillo cultivar grafted onto five commercial (1103 P, 110 R, 140Ru, 420 A, and SO4), and seven recently bred (RG2, RG3, RG4, RG6, RG7, RG8 and RG9) rootstocks and 2) to elucidate the relationships between agronomic and physiological traits conferred by grapevine rootstocks. This was carried out over three seasons (2018–2020) in a typical Mediterranean vineyard by determining water relations, leaf gas exchange, carbon isotope ratios and vegetative development and yield components. The results highlighted the different behaviour of ‘Tempranillo’ vines due to the rootstock effects on vine water status, photosynthetic performance, hydraulic conductance, vegetative growth and yield parameters. Overall, rootstocks inducing vigour and yield in the scion, such as 140Ru and RG8, showed higher leaf gas exchange rates and hydraulic conductance at the whole-plant level due to less negative water potentials, suggesting a higher water uptake and transport capacity than RG2, RG7 and RG9. The RG rootstocks showed a very wide range of ecophysiological responses, but only RG8 outperformed compared to the most widely used commercial rootstocks. Moreover, this response was modulated by the season and the block soil type, suggesting the importance of rootstock selection according to the edaphoclimatic conditions. Therefore, this study highlights the high potential of rootstocks to adapt to water scarcity by improving crop water productivity in vineyards and provides physiological insights for future studies and breeding programmes.
Embargo
Upgrading and validating a soil water balance model to predict stem water potential in vineyards
(Elsevier, 2024-12-15) Mirás-Ávalos, José M.; Escalona, José M.; Pérez-Álvarez, Eva Pilar; Romero Azorín, Pascual; Botia, Pablo; Navarro, Josefa; Torres Molina, Nazareth; Santesteban García, Gonzaga; Uriarte, David; Intrigliolo, Diego S.; Buesa, Ignacio; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura; Institute for Multidisciplinary Research in Applied Biology - IMAB
Efficient water management is pivotal for viticulture sustainability. Decision support tools can advise on how to optimize irrigation or on the feasibility of growing grapes in rainfed conditions, but reliable algorithms for assessing vine water status are required. In this context, the aim of the current study was to upgrade a soil water balance model specific for vineyards by incorporating meteorological, soil and vine vigor in equations that transform the fraction of transpirable soil water into midday stem water potential (Ψstem). The model's sensitivity to variations in the magnitude of input parameters was analyzed. Furthermore, the model was tested in a broad scope of Spanish vineyards with different grapevine cultivars (both red and white), rootstocks, plant age, soil and climatic conditions, and water regimes, totaling 129 scenarios. The model was only slightly sensitive to variations in the magnitude of most inputs, except for the fraction of transpirable water at which leaf stomatal conductance begin to decline. Moreover, the model satisfactorily reproduced the evolution of Ψstem over the growing season, although it slightly overestimated the measured ¿stem values, as the slopes of the fitted regression lines were lesser than 1 on most occasions, 76 out of 129. Nonetheless, the coefficients of determination for these relationships were greater than 0.9, except for 21 datasets. Mean errors averaged 0.024 ± 0.015 MPa, while root mean square errors averaged 0.27 ± 0.01 MPa. The index of agreement was greater than 0.75 in 51 datasets, with only three datasets showing an index of agreement lower than 0.5. Nevertheless, the deviations between observed and simulated Ψstem values did not alter the classification of the water stress undergone by grapevines. This upgraded model could constitute the core of a decision support system for water management in vineyards, applicable to both rainfed and irrigated conditions.
Open Access
Impacts of leaf removal and shoot thinning on cumulative daily light intensity and thermal time and their cascading effects of grapevine (vitis vinifera L.) berry and wine chemistry in warm climates
(Elsevier, 2020-10-23) Torres Molina, Nazareth; Martínez-Lüscher, Johann; Porte, Etienne; Yu, Runze; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Leaf removal (LR), shoot thinning (ST) and their combination (LRST) are known to increase berry solar exposure affecting berry composition and consequently improving wine quality and antioxidant properties. We hypothesized that LR, ST or their combination (LRST) would affect flavonoid content during berry ripening by means of changes of the berry microclimate (light and temperature) as well as wine composition, quality, and antioxidant properties. Thermal time and sum of light intensity thresholds were different to achieve the maximum berry anthocyanin and flavonol contents. ST mostly affected wine characteristics by increasing alcoholic content, acidity, hue and phenolic substances. Wine antioxidant capacity decreased in ST wines likely by decreases in catechin and quercetin contents. ST and LRST increased proanthocyanidin polymerization and decreased monomeric flavan-3-ols, which may reduce wine bitterness and enhance astringency. Therefore, the management of canopy should take into account the warming trends in viticulture regions, rather than being applied preemptively.
Open Access
Adapting wine grape production to climate change through canopy architecture manipulation and irrigation in warm climates
(Frontiers Media, 2022) Yu, Runze; Torres Molina, Nazareth; Tanner, Justin D.; Kacur, Sean M.; Marigliano, Lauren E.; Zumkeller, María; Gilmer, Joseph Chris; Gambetta, Gregory A.; Kurtural, Sahap Kaan; Agronomía, Biotecnología y Alimentación; Agronomia, Bioteknologia eta Elikadura
Grape growing regions are facing constant warming of the growing season temperature as well as limitations on ground water pumping used for irrigating to overcome water deficits. Trellis systems are utilized to optimize grapevine production, physiology, and berry chemistry. This study aimed to compare 6 trellis systems with 3 levels of applied water amounts based on different replacements of crop evapotranspiration (ETc) in two consecutive seasons. The treatments included a vertical shoot position (VSP), two modified VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a Guyot pruned VSP (GY) combined with 25%, 50%, and 100% ETc water replacement. The SH had greater yields, whereas HQ was slower to reach full production potential. At harvest in both years, the accumulation of anthocyanin derivatives was enhanced in SH, whereas VSPs decreased them. As crown porosity increased (mostly VSPs), berry flavonol concentration and likewise molar % of quercetin in berries increased. Conversely, as leaf area increased, total flavonol concentration and molar % of quercetin decreased, indicating a preferential arrangement of leaf area along the canopy for overexposure of grape berry with VSP types. The irrigation treatments revealed linear trends for components of yield, where greater applied water resulted in larger berry size and likewise greater yield. 25% ETc was able to increase berry anthocyanin and flavonol concentrations. Overall, this study evidenced the efficiency of trellis systems for optimizing production and berry composition in Californian climate, also, the feasibility of using flavonols as the indicator of canopy architecture.