Guenoc Valley AVA Semillon, Sauvignon blanc and Chardonnay, as well as Malbec and Petite Sirah from the estate vineyards. Petite Sirah is the leading red grape in the appellation, followed by Cabernet Sauvignon, Merlot, Petit Verdot, Carmenère, Cabernet Franc and Malbec. Among whites, Langtry grows Chardonnay, Sauvignon blanc, Semillon, Marsanne and Viognier. Langtry also has the distinction of having some of the oldest vines in California, as a couple of Syrah vines dating back to the 1850s still grow at the Tephra Ridge Vineyard. Guenoc Valley AVA The Guenoc Valley AVA is an American Viticultural Area in Lake County, California, United States, about
Petite mutation petite negative mutants. Potentially, these yeasts have a different inheritance system in place for their mitchondrial genome than "S. cerevisiae" does. The frequency at which "S. castellii" spontaneously produces petites is similar to that of "S. cerevisiae", with the mitochondrial DNA of those petites being highly altered via deletion and rearrangement. Suppressive petites of "S. cerevisiae" are the most commonly observed spontaneously created mutants, whereas in "S. castellii," the most commonly observed spontaneous mutant is the neutral petite, further leading to speculation that the transference of this mutation differs between species. Petite mutation petite (ρ–) is a mutant first discovered