Location: Horticultural Crops ResearchTitle: Influence of grapevine red blotch virus (GRBV) on Idaho ‘syrah’ grape composition
|Rennaker, Christopher - Chris|
|THOMPSON, BRANDON - University Of Idaho|
|KARASEV, ALEXANDER - University Of Idaho|
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2021
Publication Date: 5/10/2021
Citation: Lee, J., Rennaker, C.D., Thompson, B.D., Karasev, A.V. 2021. Influence of grapevine red blotch virus (GRBV) on Idaho ‘syrah’ grape composition. Scientia Horticulturae. 282:110055. https://doi.org/10.1016/j.scienta.2021.110055.
Interpretive Summary: Making fine wine begins in the vineyard with the production of high-quality fruit. Viruses, such as Grapevine red blotch virus (GRBV) can have negative impacts on both vine productivity and fruit quality. This paper is the first report on GRBV grape quality in ‘Syrah’ grapes obtained from our Idaho industry collaborators. Work was conducted for three growing seasons. Grapes from GRBV infected vines had lower quantities of sugars and anthocyanins compared to healthy vines, which indicate a delay in ripening. Grape sugar gets converted to alcohol during fermentation in wine. Anthocyanins are important phenolic compounds in grape and wine quality that contribute to its color and appearance. Findings from this work indicate GRBV may impact wine quality negatively, the importance of obtaining GRBV free planting material, and subsequent monitoring of vineyards for GRBV. GRBV might threaten the US grape industry worth $162 billion.
Technical Abstract: Grapevine red blotch virus (GRBV) infection was recently identified in an Idaho commercial vineyard. Fruit quality from healthy vines (no viruses detected), and GRBV positive (infected) vines was determined for ‘Syrah’ grapes from this vineyard. GRBV infected vines produced grapes with significantly lower total sugars (2.7 g/100g difference) and lower total anthocyanins (34 mg/100g difference). They were also lower in a single free amino acid (tryptophan, 0.4 mg of N/kg difference), yet higher in malic acid (0.13 g/100g difference) compared to grapes from healthy vines. No significant differences were seen in total organic acids, yeast assimilable nitrogen content, total free amino acids, total phenolics, or total tannins between the grapes of healthy vines versus those of GRBV infected vines. Overall, GRBV negatively influenced grape quality by reducing total sugars and total anthocyanins, which may indicate GRBV infection delayed grape ripening and could adversely affect wine quality.