Terroir 2020 banner
IVES 9 IVES Conference Series 9 Terpenoid profiles and biosynthetic gene expression pattern in Asti DOCG white muscat grapes at ripening as affected by different canopy management protocols

Terpenoid profiles and biosynthetic gene expression pattern in Asti DOCG white muscat grapes at ripening as affected by different canopy management protocols

Abstract

Aim: The main goal of this study was to find an efficient canopy management to limit the high temperature-related aroma losses of White Muscat grapes, and consequently to preserve the quality standards of Asti DOCG wines.

Methods and Results: Four different strategies have been tested in two vineyards of the Asti DOCG production area: pre-flowering leaf removal (m1), post-berry set leaf removal (m2), leaf removal at veraison (m3), and clusters thinning (m4). Control vines (m0) did not receive any thinning or defoliation. Grapes were collected at four time points: seven days before the commercial harvest, at the commercial harvest scheduled for “Asti spumante” wine, at the commercial harvest scheduled for “Moscato” wine and overripening. Free and glycosylated terpenoids content (GC-MS) as well as the expression of key genes involved in terpenoids biosynthesis and metabolism (RT-qPCR) were analysed separately in skin and pulp. The results revealed a peak of volatile accumulation, which occurred early and late throughout the sampling times. The treatments m3 and m4 were, in general, those more effective in enhancing the aroma profiles in both tissues analysed. Correspondingly, in these grapes, specific genes, such as VvDXS3 and VvGT14 resulted up-regulated. Other genes, such as VvHDR, showed different expression pattern resulting, in general, more expressed in pulp than skin, regardless the applied treatment.

Conclusions:

Based on these preliminary trials carried out in a specific production area of White Muscat, it seems that m3 and m4 treatments had a significant effect on the volatile’s accumulation in both grape skin and pulp. m1 treatment resulted to be the less effective in inducing changes in the aroma profile and the terpenoid biosynthetic pathway.

Significance and Impact of the Study: Moscato d’Asti DOCG is one of the most characteristic enological products of Piemonte (North-West Italy) wine grapes-growing area. It comes exclusively from White Muscat grapes which are exalted by the climatic and geographical conditions of the production area. Indeed, the interactions between vine and environment, limestone terrain and micro-climate typical of hilly zones leads to a characteristic fruity and sweety aroma. The characteristic aroma of Muscat wine is attributed to the presence of specific terpenoids, mainly linalool, nerol, geraniol, trans-piran linalool oxide and citronellol. The grapevine terpenoids pathway is strongly regulated by endogenous and environmental factors and among them, temperature and light exposure plays a crucial role. As recently observed, the content of these compounds is strongly decreasing due to the increasing temperatures. Higher temperature during the growing season is forcing growers to find ways to reliably control grape composition preserving the typical aroma of Asti DOCG wines. The present study could offer important information to address grower’s choice in term of canopy management that are better suited to the changing climate.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Margherita Modesti1*, Ron Shmulevitz, Stefano Brizzolara1, Daniele Eberle2, Guido Bezzo2, Pietro Tonutti1

1Life Sciences Institute, Scuola Superiore Sant’Anna, Piazza Martiri della Libertà 33, 50127 Pisa, Italy
2Consorzio per la Tutela dell’Asti DOCG. Piazza Roma 10, 14100 Asti, Italy

Contact the author

Keywords

Canopy management, Moscato d’Asti DOCG, terpenoid content and biosynthesis, climate change

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Analysis of Cabernet Sauvignon and Aglianico winegrape (V. vinifera L.) responses to different pedo-climatic environments in southern Italy

Water deficit is one of the most important effects of climate change able to affect agricultural sectors. In general, it determines a reduction in biomass production, and for some plants, as in the case of grapevine, it can endorse fruit quality. The monitoring and management of plant water stress in the vineyard

Assessment of the impact of actions in the vineyard and its surrounding environment on biodiversity in Rioja Alavesa (Spain)

Traditional viticulture areas have experienced in the last decades an intensification of field practices, linked to an increased use of fertilisers and phytosanitary products, and to a more intensive mechanization and uniformization of the landscape. This change in management has sometimes led to higher rates of soil erosion andloss of soil structure, fertility decline, groundwater contamination, and to an increased pressure of pests and diseases. Additionally, intensification usually leads to a simplification of landscapes, of particular concern in prestigious wine grape regions where the economical revenue encourages the conversion of land use from natural habitats to high value wine grape production. To revert this trend, it is necessary that growers implement actions that promote biodiversity in their vineyards. The aim of this study is to assess the impact of the implementation of cover crops, vegetational corridors, dry stone walls and vineyard biodiversity hotspots estimated through the study of arthropods. The work has been carried out in four vineyards in Rioja Alavesa belonging to Ostatu winery, where these infrastructures were implemented in 2020. The presence and diversity of arthropods was studied by capturing them at different times in the season and at different distances from the infrastructure using pit-fall traps in the soil and yellow, white and blue chromatic traps at the canopy level. This is a preliminary study in which all adult insects were sorted to the taxonomic level of order and Coleoptera were classified to morphospecies. The results obtained show that there is a relationship between the basic characteristics of the vineyard and the arthropods captured, with a positive effect, although also dependent on the vineyard, of the presence of infrastructure.

Different soil types and relief influence the quality of Merlot grapes in a relatively small area in the Vipava Valley (Slovenia) in relation to the vine water status

Besides location and microclimatic conditions, soil plays an important role in the quality of grapes and wine. Soil properties influence…

A better understanding of the climate effect on anthocyanin accumulation in grapes using a machine learning approach

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.

Grape must quality and mesoclimatic variability in Fruška Gora wine-growing region, Serbia

The Fruška Gora mountain is a traditional wine-growing region in Serbia situated in the Pannonian Basin. Due to such a position, the vicinity of the Danube River and the presence of concave configuration, it is suitable for grape production. This paper provides analyses of spatial variations in meteorological parameters and grape juice quality within Fruška Gora wine region over three consecutive vintages (2018-2020). The examined period can be defined as warm with cool nights during September (AVG 18,9°C; GDD 1918°C; CI 12°CF) and with the presence of mesoclimatic variability. The East part of the study area was somewhat drier and hotter compared to other parts of the region. The analyses of grape must samples (190 in total) of five cultivars (Cabernet-Sauvignon, Merlot, Chardonnay, Sauvignon blanc and Grašac (Welschriesling)) commonly grown across the region (19 sites), were performed using Fourier Transform Infrared Technology (FTIR). Among all cultivars, Sauvignon blanc was harvested first in the East area (DOY=246±5, GDD at harvest=1552±74, 22.2±0.7 °Brix), while the latest harvest was recorded for Cabernet-Sauvignon in the West (DOY=283±5, GDD at harvest=1936±187, 23.4±1.0 °Brix ). Both the red and white cultivars had higher acidity and YAN in the grape must if the vines were grown in the North and East compared to South and West areas. According to PCA analysis, Grašac showed the lowest variation in grape must chemical composition. Thus, the results confirm that Grašac is the most stable cultivar in Fruška Gora. All monitored cultivars reached technological fruit ripeness by the end of the growing season. However, it was difficult to reach full ripeness of red cultivars, mostly beacuse of uncoupling of technolocical and phenolic ripeness. Thus, Cabernet-Sauvignon had higher variations in GDD sums at harvest compared to other cultivars, which probably increased variations in grape must quality.