Genetic research at UC Davis uncovered the origins of the grape Petite Sirah. Petite Sirah (aka Durif) is the outcome of an experiment conducted by a French nurseryman, Dr. Francois Durif, in the 1860s. In an attempt to create a varietal resistant to mildew, Durif crossed Syrah and Peloursin (a grape no longer in commerce) and named this new variety after himself.
However, his inability to produce a quality wine nullified the value of this mildew-resistant variety in France. Petite Sirah does well in very warm climates and is grown in abundance in South America, parts of California (like East Paso Robles) and Australia. Australians refer to Syrah as Shiraz and their wines are typically more lush, ripe and fruit-forward than Old World Syrahs.