THE INHERITANCE OF ANTHOCYANIN PIGMENTATION IN POTATO (SOLANUM-TUBEROSUM L) AND MAPPING OF TUBER SKIN COLOR LOCI USING RFLPS

Two existing genetic models for anthocyanin pigmentation are compared: the genetic model as proposed by Lunden (1937, 1960, 1974) for tetrap loid potato Solanum tuberosum group Tuberosum and the model by Dodds & Long (1955, 1956) for diploid cultivated Solanum species. By crossing well defined genotypes from both genetic sources it was demonstrated that locus R/R(pw) and locus D are allelic. Both loci are involved in the biosynthesis of red anthocyanins. We propose to maintain the symbo l D for this locus. Tuber skin colour is expressed due to the compleme ntary action of one locus involved in anthocyanin biosynthesis and a s econd locus involved in tissue-specific regulation of anthocyanin expr ession. The inheritance of two phenotypes of skin colour was investiga ted in this study: pigmentation of the epidermis and pigmentation of t he cortex. In two different populations the loci determining the two p henotypes were located with RFLPs on the map of the potato genome, at approximately the same position as the earlier mapped PSC locus on chr omosome 10. Lunden proposed the symbols E and R for the loci determini ng these phenotypes. Dodds and Long proposed only one locus I for tube r skin colour without describing these different phenotypes. The ident ity and nomenclature of the loci studied by the various authors are di scussed.