Production of an interspecific somatic hybrid between peppermint and gingermint

Abstract Interspecific somatic hybridization by protoplast fusion was carried out between two species of mints. Protoplasts isolated from leaf-mesophyll cells of peppermint ( Mentha piperita L. cv. Blackmint) were fused with those of a garden variety mint called ‘gingermint’ ( Mentha gentilis L. cv. Variegata) by the electrofusion method. These protoplasts divided to form calli under the conditions developed for peppermint protoplast culture. Callus-derived shoots were grown to whole plants, and some with intermediate character between the parental plants were tested for their volatile constituents by gas chromatography (GC). Among the 4 plants investigated, one had three major volatile constituents, menthone, menthol (major components of peppermint oil) and linalool (major component of gingermint oil). Chromosome counts and random amplified polymorphic DNA analysis indicated that it was an interspecific somatic hybrid between two species.