terclim by ICS banner
IVES 9 IVES Conference Series 9 Physiological means to curb the enthusiasm of viruses from infecting grapevines  

Physiological means to curb the enthusiasm of viruses from infecting grapevines  

Abstract

The two most deadly viruses infecting and threatening the productivity of grapevines worldwide are leafroll and red blotch viruses. There is no cure for viral diseases other than roguing the symptomatic vines and replacing them with certified vines derived from clean, virus-tested stocks. 
Given that phloem plays a central role in virus infection, this study aimed to purge the virus by girdling the phloem of leafroll-infected vines at different phenological stages of infected grapevines. Phloem-girdling was performed on canes at veraison to varying regions between the proximal and distal clusters. The vines responded to gridling by forming a callus to bridge the gap and restore vascular functionality. The whole lamina of the leaves above the girdled region turned red due to anthocyanin accumulation triggered by sugars confined to the leaf. This reddening was quite different from the reddening that typically occurs in the leafroll-infected vines, wherein the whole lamina turned red except for the lamina close to the major and minor veins, giving the impression of green veins. The girdled canes showed a low virus concentration compared to the ungirdled canes. Also, the primary metabolites, such as sugars, acids, and nitrogenous compounds, and the secondary metabolites, such as flavanols (tannins), flavonols, and anthocyanins desired for making wine did not vary much between the girdled and ungirdled shoots. This study showed that by girdling the phloem over several growing seasons can reduce the virus load in the infected vines, restoring the vine’s health.

DOI:

Publication date: June 13, 2024

Issue: Open GPB 2024

Type: Poster

Authors

Bhaskar Bondada*

Washington State University Tri-Cities, Wine Science Center, Richland, WA, USA

Contact the author*

Keywords

Acids, Anthocyanins, callus, girdling, phenolics, phloem, sugars

Tags

IVES Conference Series | Open GPB | Open GPB 2024

Citation

Related articles…

Behavior of disease resistant grapevine varieties to downy mildew (Plasmopara viticola) infections in the Castelli Romani area (Central Italy)

At CREA – Centro di Ricerca di Viticoltura ed Enologia, based in Velletri (RM), an experimental vineyard including 10 downy mildew resistent/tolerant grape varieties and two susceptible varieties was set up with the principal goal to evaluate the behavoir of these varieties in term of resistance to downy mildew (Plasmopara viticola). This evaluation, together to oenological studies, are necessary to register them also in Regional Register (in Lazio region). Monitoring of behavior towards Plasmopara viticulture of resistant vines were done in 2020 and 2021 at different times (phenological stages) and until harvesting, according to an international standard code BBCH a centesimal phenological scale, based on coding system.

Oligosaccharides in red wines: could their structure and composition be influenced by the grape-growing

Oligosaccharides have only recently been characterized in wine, and the information on composition and content is still limited. In wine, these molecules are mainly natural byproducts of the degradation of grape berry cell wall polysaccharides. Wine oligosaccharides present several physicochemical properties, being one relevant factor linked to the astringency perception of wines (1,2). A terroir can be defined as a grouping of homogeneous environmental units based on the typicality of the products obtained. This notion is particularly associated with wine, being the climate and the soil two of the major elements of terroir concept.

HYDROXYTYROSOL PRODUCTION BY DIFFERENT YEAST STRAINS: SACCHAROMYCES AND NON-SACCHAROMYCES AND THE RELATION WITH THE NITROGEN CONSUMPTION

Hydroxytyrosol (HT) is a phenolic compound with extensive bioactive properties. It is present in olives, olive oil and wines. Its occurrence in wines is partly due to yeast synthetise tyrosol from tyrosine by the Ehrlich pathway, which is subsequently hydroxylated to .
The aim of the present work is to study how different yeast strains can influence in the HT production and, how the different nitrogen consumption of each strain can interfere the production of bioactive compounds.

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Functionality of different inter-stimulus rinse protocols for the sensory analysis of wildfire affected wines

From the effect of global climate change, wildfire occurrence during grape ripening has increased. These wildfires produce smoke that can carry organic compounds to a vineyard. These smoke compounds are adsorbed in the grape berry and result in wines with elevated levels of smoke-related phenols. These wines are described as having a smokey, burnt, and dirty aroma (Kristic et al, 2015). Not only are volatile phenols carried by smoke, but additionally glycoconjugate forms of these phenols are present as will. These have been found to have a large impact on the flavor of wines, being the cause of a lasting ashy aftertaste post consumption (Parker et al, 2012). When evaluating the sensory profile of these wines when tasted one after the other, there is an observed problem due to the lasting nature of these undesirable attributes and high level of carry-over from sample to sample. The aim of this work is to evaluate the extent this carryover occurs, along with the best sensory practices to mitigate its influence via different inter-stimulus rinse protocols.