Terroir 2020 banner
IVES 9 IVES Conference Series 9 Regional impact on rootstock/scion mediated methoxypyrazine accumulation in rachis

Regional impact on rootstock/scion mediated methoxypyrazine accumulation in rachis

Abstract

Aim: To investigate the impact of Geographical Indications (GI) of South Australia on the rootstock/scion-mediated methoxypyrazine accumulation within the rachis of Shiraz and Cabernet Sauvignon. 

Methods and Results: Cabernet Sauvignon and Shiraz bunches were sampled at maturity from two South Australian GIs over the 2019 and 2020 harvest periods. From each region, a minimum of 18 bunches per rootstock/scion combination were sampled from across the vineyard and their rachis material was assessed for 3-isobutyl-2-methoxypyrazine (IBMP). Results indicated that region and rootstock choice significantly affect the concentrations of methoxypyrazines within the rachis material of both Shiraz and Cabernet Sauvignon varieties at harvest. 

Conclusion: 

This research highlights the effect of regionality on the concentration of methoxypyrazines within the rachis material of Cabernet and Shiraz vines grown on common rootstock varieties. The outcomes will conceivably inform viticulturalists and winemakers of how methoxypyrazine characteristics of Shiraz and Cabernet Sauvignon rachis are impacted by common rootstock/scion combinations permitting informed rootstock selection and assisting in production of a target wine style.

Significance and Impact of the Study: The presence of rachis material during red must fermentation can confer methoxypyrazines to the wine. The presence of methoxypyrazines, and predominately 3-isobutyl-2-methoxypyrazine (IBMP), in red wine can impact the flavour and aroma profile due to their ‘green’ and ‘earthy’ characteristics. Interestingly, this phenomenon has been shown to impact the aroma profile of Shiraz wines, a variety that has not been shown to naturally produce methoxypyrazines within the berries. Furthermore, it appears that the concentration of methoxypyrazines within the rachis is mediated by rootstock/scion combination and the region in which the vines are grown. As rootstock uptake increases across Australia in response to biological threats and abiotic stresses, an understanding of the viticultural and regional influences on rootstock/scion mediated rachis composition is essential to facilitate the production of high-quality Australian wines under increasingly challenging conditions.

DOI:

Publication date: March 25, 2021

Issue: Terroir 2020

Type : Video

Authors

Ross D. Sanders1,2,3, Paul K. Boss1,3, Dimitra L. Capone1,2, Catherine Kidman4, David W. Jeffery1,2*

1Australian Research Council Training Centre for Innovative Wine Production, The University of Adelaide, PMB1 Glen Osmond, SA, 5064, Australia
2School of Agriculture, Food and Wine, The University of Adelaide, Waite Campus, PMB1 Glen Osmond, SA, 5064, Australia
3CSIRO Agriculture and Food, Locked Bag 2, Glen Osmond, SA 5064, Australia
4Wynns Coonawarra Estate, 77 Memorial Drive, Coonawarra, SA 5263, Australia

Contact the author

Keywords

Shiraz, Cabernet Sauvignon, Vitis vinifera, wine aroma

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Vitamins in grape must: let’s lift a corner of the veil

Although vitamins stand as major actors to yeasts prime metabolic pathways, their significance in oenology and winemaking remains rather obscure nowadays, having been mostly unexplored for several decades.

Flavor Enhancement Of Neutral White Wines By Mango Peel Products

Varietal flavor is commonly known as the aromatic character of a wine in which the aroma of a particular grape variety predominates. However, not all varieties present particularly pronounced aromas. Therefore, different methods are constantly sought to enhance the aroma of wines with neutral aromatic characteristics, such as the use of glycosidases (1), certain yeast strains (2) or maceration with different agricultural products. In this work, aiming to improve the sensory profile together with the diversification of this product, white wines, derived from a neutral grape variety, were elaborated with the addition of mango peel by-products.

Impact of mycorrhizal inoculation of ‘Monastrell’ grapevines grafted onto different conventional vs. newly breed rootstocks 

Grafting Vitis vinifera L. (wine traditional cultivars) onto North American grapevine species or hybrids is a common practice in viticulture given their tolerance against phylloxera (Daktulosphaira vitifoliae). However, rootstock genetic background affects the response of grapevines to environmental stresses and their ability for establishing a symbiotic relationship with the microbial communities, and more specifically with arbuscular mycorrhizal fungi (AMF).
The aim of this study was to evaluate Monastrell variety (clone ENTAV 369) grafted onto three rootstocks (140Ru, 110R and RG8) characterized by a different genetic background, in combination with AMF inoculation (Rhizophagus irregularis) vs. a non-inoculated control with regards to vegetative growth, leaf gas exchange parameters, and mycorrhization.

is the overall ecological awarness among Spanish winemakers related to their attitudes towards natural wines?

The Agenda 2030 of the EU sets out the main guidelines for transitioning towards a resilient, green and safe economy. To this regard, the wine sector is experiencing an ecological transition in different ways such as increasing the production of ecological crops, or promoting the production of wines under more environmental-friendly and healthier (i.e., lower levels of SO2) products. These alternatives to conventional production are a smaller proportion of wines, in constant growth and demand, and follow alternative and minority practices, which range from sustainable to deeply philosophical thoughts. Among these methods there are organic, biodynamic and, more recently, natural wines.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.