The genetics of anthocyanin reddening in apple fruit skin

Author: Benjamin Ewa Ubi

Received 11 September 2003, accepted 15 January 2004.

Abstract

Among apple fruit characters, the red coloration of the fruit skin derived mainly from a class of flavonoids called anthocyanins, is of great importance. This fruit quality characteristic largely determines the consumer appeal and impacts significantly on the market value of the produce. Anthocyanin reddening in apple fruit skin has been a subject of genetic studies since the 1930‘s. Several studies have indicated a monogenic mode of inheritance and a single dominant gene, R_f, proposed to control anthocyanin reddening on apple fruit skin. Recent molecular genetic studies strongly corroborate the hypothesis of a major gene inheritance as has been reported in the earlier literature. However, there has been much controversy among researchers and many of the studies have been inconclusive. Additional genetic studies based on common standards for color categorization in apple, relatively larger population sizes, and biochemical genetic studies especially those based on the main anthocyanin pigment in apple skin, cyanidin-3-galactoside, would be needed to confirm the inheritance of color in apple skin. In this article, an updated summary of published reports on the inheritance of anthocyanin reddening in apple fruit skin is presented.