Genetic control of geranial formation in Perilla frutescens.

A novel chemotype (C type) having a lemon-like odor segregated out in the F2 progeny of a cross between PK and PL chemotypes of Perilla frutescens. Chemical analysis of C-type plants revealed that geranial was the major component of essential oils in the leaves. Genetic analysis suggested that geranial is accumulated by individuals homozygous for two pairs of recessive, polymeric genes, fr1 and fr2, which are incapable of converting geranial into perillene.