Por: Cecilia B. Agüero, José G. Rodríguez, Liliana E. Martínez, Gerald S. Dangl, and Carole P. Meredith.

Torrontés riojano is an aromatic white grape variety cultivated in Argentina that produces a dry wine with distinct muscat flavor. Two other Torrontés types, Torrontés sanjuanino and Torrontés mendocino, are of lower enological quality. Origin of the Torrontés cultivars has been the subject of speculation because efforts to relate them to European varieties have been unsuccessful. Microsatellite DNA polymorphism analysis was used to characterize these three cultivars and to attempt to clarify their origin. Moscatel amarillo, an Argentine cultivar with a phenotype very similar to that of Torrontés riojano, was also included in the study. Twenty microsatellite loci were analyzed in several accessions of each of the four cultivars. All four cultivars were found to be distinct. The results indicated, with a high degree of probability, that Torrontés riojano, Torrontés sanjuanino, and Moscatel amarillo are each the progeny of a cross between Muscat of Alexandria and Criolla chica and that Torrontes mendocino is also likely
the progeny of Muscat of Alexandria, although the other parent has not been identified. A close relationship between the Torrontés and Muscat of Alexandria has been suspected, but the genetic contribution of Criolla chica was unexpected.