The French ampelographer Paul Truel (1924-2014) is considered one of the world's leading experts in this field. He studied at the Department of Viticulture at the French University of Montpellier (Languedoc). This was at the time when Pierre Galet (1921-2019) held the chair of viticulture there. Like him, he was an absolute specialist in the identification of grape varieties, often spontaneously and purely visually based on their phenotype. For many years, Paul Truel was in charge of the collection of vine varieties at the Domaine de Vassal in Montpellier.
Among his acknowledged achievements are the examination of the vine assortment in Australia and Portugal as well as in the Viticulture Institute Magarach in the Ukraine. He was instrumental in the determination and description of the varieties Abouriou, Alarije, Canari Noir, Bouillet, Crouchen, Muscadelle, Ondenc and Roussette d'Ayze. He also made the claim, which was only proven by DNA analyses much later, that the two varieties Durif and Petite Sirah were identical.
Unfortunately, unlike his colleague Galet, Paul Truel never published much, which is why he was wrongly overshadowed by Galet. Together with Jean Branas, the work "Variétés de raisins de table: nomenclature, description, sélection, amélioration" was published in 1965. Paul Truel concentrated almost exclusively on the collection and identification of grape varieties. He created the new varieties Aranel, Caladoc, Chasan, Clarin, Danlas, Ganson, Gramon, Lival, Marselan, Monerac, Portan, Ribol and Segalin, among others. In Vassal, he created an extensive vine variety index and a well-sorted herbarium (plant collection), which are important tools for determining vine varieties.