Designation (also called original variety) for a grape variety that is considered the origin(mother or father) of many other varieties within a large group in the vine family tree. Naturally, these are exclusively very old grape varieties. Most of the cultivated varieties cultivated in Western Europe today can be traced back to a relatively small group of lead varieties and their spontaneous (natural) crossings. The most important is probably Gouais Blanc (Heunisch or White Heunisch), of which there are well over 100 varieties, including Riesling (Germany), Chardonnay (France), Blaufränkisch and Silvaner (Austria), and Furmint (Hungary).
Also the grape varieties Traminer (French Savagnin Blanc, most common variety Gewürztraminer) Chenin Blanc, Sauvignon Blanc and Roter Veltliner, as well as Pinot (often together with Gouais Blanc often together as a parent couple) have left numerous traces. More than 150 grape varieties are descended from the three most important Gouais Blanc, Pinot or Traminer alone through most likely natural crossing. Other leading varieties with many descendants are Alfrocheiro, Cabernet Franc, Cayetana Blanca, Chasselas, Rèze, Garganega, Hebén, Luglienga Bianca, Muscat Blanc, Nebbiolo, Sangiovese, Teroldego and Tribidrag, as well as in South America the Listán Prieto (Criolla Chica, Mission, País) and Muscat d'Alexandrie imported from Spain.
Some groups of grape varieties are often erroneously called "variety family" because there are numerous varieties with the same part of the name. The best known are Lambrusco, Malvasia, Muscatel, Trebbiano and Vernaccia. Quite a few within these groups are not related to each other at all. For more information on this topic, see the vine family tree and a list of relevant keywords under vine.
The main variety is also the main variety (usually well over half) in a cuvée (blend) and also the most important grape variety in the variety chart of a winery.