Genes affecting flower colour and pH of flower limb homogenates in Petunia hybrida

Abstract
In Petunia hybrida four complementary genes are present, each having, if homozygous recessive a blueing effect on the flower colour. These genes have no qualitative or quantitative effect on anthocyanins and flavonols. In mutants homozygous recessive for one (or more) of the Ph genes the pH of aqueous flower limb homogenates is increased. It is assumed that the Ph genes in Petunia are involved in maintaining the pH in the vacuole fluid in the flower.