Tempranillo with temperatures dropping by as much as 16 °C (30 °F) from the daytime high. The Tempranillo grape is one of the few grapes that can adapt and thrive in continental Mediterranean climates like this. Pests and diseases are a serious problem for this grape variety, since it has little resistance to either. The grape forms compact, cylindrical bunches of spherical, deep blue-black fruit with a colourless pulp. The leaves are large with five overlapping lobes. The Tempranillo root absorbs potassium easily, which facilitates pH levels of 3.6 in the pulp and 4.3 in the skin when it reaches maturity.
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