DNA profiling
Trousseau originated in eastern France where it was once widely cultivated, and DNA profiling has indicated that the variety has a parent-offspring relationship with Savagnin, and that it is a sibling to Chenin blanc and Sauvignon blanc. DNA profiling has likewise shown that Trousseau has been cultivated on the Iberian Peninsula for at least 200 years under several different names, including Bastardo, but it is unknown how it came to be introduced there.