Varietal authentication of Brunello di Montalcino wine using a minimal panel of DNA markers

Abstract

Wine DNA fingerprinting (WDF), retrieved from the amplification of a wider panel of Simple Sequence Repeat (SSR) marker mappings in the Vitis vinifera L. genome, was used to assess the monovarietal nature of Brunello di Montalcino wine. The reliability of the varietal assessment was carried out by estimating the PI values associated with resolutive unrooted dendrograms depicting the correct varietal nature of different wines. As few as five SSR DNA markers associated with a PI value of one over a million or less, PI ≤ 10−6, can identify the purity of Sangiovese against Merlot, Pinot Noir, Cabernet Sauvignon, Primitivo (Zinfandel), and genetic variants of the Sangiovese as plant references. WDF was used on other monovarietal wines obtained from Cabernet Sauvignon, Merlot, Chardonnay, and Pinot Noir to test the feasibility of the method. In blended wines, the test was able to trace the main varietal component in a three-variety blend, keeping the varietal fingerprint detectable when the main variety was at least 75% (v/v). The data confirm how local genetic variants of Sangiovese can be tracked in commercial wines, becoming, at wine makers’ demand, part of an evidence synthesis of geographical origin.