Geek: Malvasia Bianca’s DNA

Author of the immortal phrase “In wine there is truth” and one of the earliest writers to describe grape cultivation and winemaking practices as well as the concept of terroir, Pliny the Elder appears to have appreciated the floral loveliness of wines produced from Malvasia grapes. Although he may not call them “Malvasia,” Pliny gives high accolades in his first-century encyclopedia Natural History to the sweet, aromatic wines of southern Italy, a description that could reference both the Malvasia fruit and the resulting wine. Modern day viticulture scientists share a kindred link with Pliny, even as they employ the most advanced equipment and cutting-edge techniques for studying grapevine genetics.

While the exact origin of the Malvasia family of grapes remains a mystery, modern DNA testing indicates that this was one of the earliest vines cultivated. In 2007, the American Journal of Enology and Viticulture published a paper by several French viticulture scientists that identified shared genetic patterns within a collection of Malvasia specimens at the Domaine de Vassal Grape Germplasm Repository. In their paper entitled “Relationships and Genetic Diversity within the Accessions Related to Malvasia Held in the Domaine de Vassal Grape Germplasm Repository,” Thierry Lacombe et al. attempted to outline the genetic relationships among the vast collection of Malvasia-named grape vines held by L’Institut National de la Recherche Agronomique (INRA) in Paris.

In the repository, these scientists examined 70 Malvasia-associated accessións (or selections) using ampelography and Simple Sequence Repeat (SSR) DNA analysis. They were attempting to determine the potential number of individual Malvasia varieties in existence in order to identify how many of these selections were the same cultivar and how many were genetically distinct. The researchers were trying to reduce some of the confusion that results from so many different vines being named “Malvasia.”  This exhaustive study produced several interesting findings. For one, of the 70 accessións studied, it was determined that there were actually 49 distinct varieties. This research determined that, although there are many vines that have “Malvasia” in their names, most are not actually related by genetic code or parentage. This helps explain the inconsistency in the characteristics of wines that share the name “Malvasia.”

Of the 70 selections, 73% were white-skinned grapes and only eight selections were considered aromatic varieties, including Malvasia Bianca. The vast majority of Malvasia grapes are not aromatic. This research proposed that four subgroups of Malvasia exist: specimens in each subgroup were found to be genetically more similar to members of their subgroup than to specimens in the other subgroups. This research also demonstrated that the aromatic subgroup of Malvasia shares portions of gene sequences with the powerfully scented Muscat d’Alexandrie grape, which further explains the highly aromatic character displayed by the Malvasia Bianca cultivar.

The study also revealed that there is no clear common denominator among the Malvasia accessións. The name “Malvasia” is not directly based on origin or determined traits.  Rather, Malvasia is more of a generic name applied to many grape varieties growing in the Mediterranean Basin than it is a group of grape varieties that are closely related genetically. Ultimately, this research illuminated how not all Malvasias are (genetically) equal and that only the most fragrant wines can be produced from the aromatic subgroup of the Malvasia family.

– by Ken Volk

Ampelography is the science of determining grape vine varieties by leaf shape, growing habits, and physical morphology