Submitted to: International Conference of Polyphenols
Publication Type: Abstract Only
Publication Acceptance Date: 4/4/2008
Publication Date: 7/8/2008
Citation: Lee, J., Martin, R.R. 2008. Impact of Grapevine leafroll associated virus -2 and -3, on phenolic compounds: commercial vineyard example. International Conference of Polyphenols.
Technical Abstract: Making premium wine begins in the vineyard with the production of high quality fruit. Recent reports on the incidence and spread of GLRaVs in vineyards in Oregon and Washington led to this study on the impact of these viruses on phenolic compounds in fruit. ‘Pinot noir’ is the dominant and most valuable wine grape cultivar grown in Oregon. One study has reported on the impact of GLRaV on the anthocyanin profile of a red grape: Vitis vinifera L. cv. ‘Nebbiolo’. Other studies have reported on the incidence and detection of GLRaVs and their impact on fruit maturity. Symptoms of GLRaVs are dependent on factors such as cultivar, clone, rootstock and vine age, but a systematic investigation into the relationships between vine and virus status and the impacts on fruit quality is needed. The objective of this study was to identify the profile and accumulation of indicator compounds, mainly phenolics responsible for high-quality organoleptic character of ‘Pinot noir’, in vines infected with GLRaV. Fruit was collected from two commercial vineyards located within the Willamette Valley of Oregon, one infected with GLRaV-2 and one with GLRaV-3. Fruit samples were collected based on visual symptoms of leafroll for two growing seasons, with virus infection confirmed by RT-PCR. Basic fruit maturity indices (pH, TA, % soluble solids, berry weights, and cluster weights) were measured. A detailed phenolic analysis (anthocyanins, flavonol-glycosides, flavanol monomers, etc) was conducted for all samples by HPLC/DAD with or without MS detection. Overall, there were lower levels of phenolics found in the grape samples infected with either GLRaV-2, or -3 compared to adjacent noninfected plants. Detailed findings from this study will be presented. This work will contribute towards the understanding of how vine virus status impacts fruit quality and the importance of virus-free vines for future vineyard plantings.