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 mutation petite (ρ–) is a mutant first discovered in the yeast "Saccharomyces cerevisiae". Due to the defect in the respiratory chain, 'petite' yeast are unable to grow on media containing only non-fermentable carbon sources (such as glycerol or ethanol) and form small colonies when grown in the presence of fermentable carbon sources (such as glucose). The petite phenotype can be caused by the absence of, or mutations in, mitochondrial DNA (termed "cytoplasmic Petites"), or by mutations in nuclear-encoded genes involved in oxidative phosphorylation. A neutral petite produces all wild type progeny when crossed with wild type. petite mutations can