Molecular fingerprinting of some Mentha species by sequencing and RFLP analysis of the 5S-rRNA non-transcribed spacer region

Abstract

The genus Mentha is of particular economic importance. The development of new methods for the characterisation of Mentha species is crucial for their unequivocal identification. Amplification of the non-transcribed spacer (NTS) of the 5S-rRNA gene was used to characterise some Mentha species, which revealed a high-specific variability. Cloning and sequencing of all amplified NTS fragments enabled the discrimination among almost all species. In silico and experimental analyses identified specific restriction sites on the amplified 5S-NTS regions, facilitating the rapid and unambiguous discrimination of all the different species by polymerase chain reaction–restriction fragment length polymorphism. A direct comparison between essential oil composition and DNA fingerprinting confirmed a relationship between chemical and molecular data.

Keywords::

• Mentha species
• molecular discrimination
• essential oils
• PCR–RFLP
• 5S-rRNA NTS

Acknowledgements

The authors are grateful to the USDA National Clonal Germplasm Repository (NCGR, Arctic and Subarctic Plant Gene Bank Palmer, Alaska) and to the Millennium Seed Bank (MSB, Royal Botanic Garden, Kew) for providing Mentha accessions. The authors also thank G. Gnavi for technical assistance during the early steps of this project. This work was partly sponsored by the Doctorate School of Science and High Technology of the University of Turin.