Stilbenes in the different organs of Vitis vinifera cv. Merlot grafted on TK5BB rootstock

Abstract

Aim: To determine which of the grapevine organs serving as viticultural by-products are the richest in biological active stilbenes, like t-piceid, t-resveratrol and e-viniferin. Methods and results: Nine organs, namely roots, canes, buds, shoot tips, inflorescences, clusters at veraison, mature berry skins, seeds and cluster stems, of Vitis vinifera cv. Merlot grafted on TK5BB rootstock were collected during one year and their ethanolic extracts were analysed via HPLC-FLD. The stilbene content varied widely among the different organs, the lowest being 3.15 mg/kg dry weight (dw) in the seeds and the highest 2265 mg/kg dw in the buds. Conclusion: The present research demonstrated that different grapevine organs contain different amounts of stilbene in the vineyard. The winter-buds, the roots and the mature cane internodes of Merlot are significantly richer in t-resveratrol and e-viniferin than the green vegetative and generative parts that we examined over one year. Significance and impact of the study: To our knowledge, there has been no assessment of stilbene content in several plant organs of a vine cultivar in a field study. Our research pointed out that pruned canes could be a primary source of stilbene for the health industry. Roots, which are a by-product of grapevine nurseries, are also rich in stilbene.