Tempranillo blanco La Rioja province of northern Spain. While Tempranillo is a dark-skin variety used to produce red wine, the grower discovered that one of his vines had undergone a mutation that produced yellow-green clusters after veraison. In the 21st century, the University of La Rioja and the Agricultural Research and Development Centre (CIDA) worked with local wineries (such as Viña Ijalba) to help revive and establish native grape varieties such as Tempranillo. Currently Tempranillo blanco is found only in the Rioja wine region of Spain. In 2007, the Spanish Institute for Foreign Trade working with the "Consejo Regulador" of the Rioja
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