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…

Enhancing hydric stress tolerance by editing the VviMYB60 promoter with CRISPR/Cas9 

Climate change presents increasing challenges to viticulture, particularly with rising water stress contributing significantly to yield losses and damages. The identification of the MYB60 transcription factor, which regulates stomatal opening and closing in Arabidopsis thaliana and Vitis vinifera, offers potential solutions. Notably, knockout studies in Arabidopsis have shown reduced stomatal opening and increased drought tolerance in myb60 mutants. Additionally, the grapevine ortholog, VviMYB60, can restore the wild-type phenotype of Arabidopsis myb60 mutants. Further investigation of the Arabidopsis promoter region has revealed that mutations in DOF motifs lead to reduced expression of AtMYB60.

Viticultural Climatic Zoning and Digital Mapping of Rio Grande do Sul – Brazil, using Indices of the Géoviticulture MCC System

The State Rio Grande do Sul is the main producer of Brazilian fine wines, with four viticultural regions. The objective is the characterization of the viticultural climatic potential of the State (total surface of 281.749 km2). The methodology use the Géoviticulture Multicriteria Climatic Classification System (Géoviticulture MCC System), based on three climatic indices – Dryness Index (DI), Heliotermal Index (HI) and Cool Night Index (CI).

Modelling grape and wine quality through PLS Spline statistical method

Started in 1994, this project intends to explain quality of grapes and wines using data of soil, climate and vineyard that are currently used in field trials.

Automated red microvinification (1kg) adapted to the needs of varietal innovation

The creation of disease-resistant varieties adapted to climate change is a key challenge for the future of the wine industry. At present, the selection of these new varieties is essentially based on screening for genetic markers of resistance and agronomic criteria, due to the small number of vines available per genotype. Integrating screening for oenological criteria into the early stages of selection would speed up this process.

Photoprotective extracts from agri-food waste to prevent the effect of light in rosé wines 

Light is responsible for adverse reactions in wine including the formation of unpleasant flavors, loss of vitamins or photodegradation of anthocyanins. Among them, the riboflavin degradation leads to the formation of undesirable volatile compounds, known as light-struck taste. These photo-chemical reactions could be avoided by simply using opaque packaging. However, most rosé wines are kept in transparent bottles due to different commercial reasons. Some agri-food waste extracts have been studied for their photoprotective action which turn to be highly correlated with phenolic content [1].