Identification of secondary metabolites and essential oils from different Mint species (Mentha x piperita L.ve Mentha pulegium L.) grown from naturally cutting and developed through tissue culture

In this study, two mint species (Mentha x piperita L., Mentha pulegium L.) were developed by two different methods; one by natural cuttings and the other by micropropagation. This research aim to identify and compare the volatile compounds and secondary metabolites in the leaves of both menthe species developed through natural cuttings and by micropropagation. At the same time, some morphological and physiological parameters of these plants grown these two methods were studied. Besides, callus in these two species were generated by using different hormonal ratios and concentrations. The volatile components of plants in leaf samples were extracted by the Headspace-Solid Phase Microextraction (HS-SPME) technique, and metabolites were analyzed by GC-MS.Data show that the successful root and stem formation took place one week after growing on MS media supplied with 100 µl/l NAA (Naphthylacetic acid) and 600µL/l IBA ( Indole Butyric Acid). Through micropropagation, both Mentha spp. Increased in multiplication rates around 6-fold per month compared to the traditional propagation method. Hormone levels of 100 µl/l NAA and 250µL/l bap (Benzylaminopurine) were found to be most appropriate for callus development of Mentha pulegium species. GC-MS analysis showed that the leaves of Mentha x piperita developed by Micropropagation contain 7.22 % limonene, 76.16 % carvone, 0.99 % caryophyllene and 4.08 % beta-mirsen. On the other Mentha grown by natural cutting had 2.6 % Limonene, 22.28 % menthol, 17.34 % P-menthon, 6,23 % caryophyllene, 15.28 % carvone and 1.2 % beta-myrcene in their leaves. Mentha pulegium L. developed by micropropagation method had 68.16 % pulegon, 7.24 % carvone, 3.47 % piperitenone, 1.99 % 3-octanone and 2.00 % menthalactone were observed in their leaf samples. On the contrary plants developed from natural cuttings had 90.75 % Pulegone, 1.00 % piperitenone, 0.02 % menthalactone and 0.03 % 3-octanone in their leaves. Mentha x piperita, developed by micropropagation method, has 5 times more karvon, 3 times more limonene and 4 times more beta myrcene than the plant grown through natural cuttings. Mentha pulegium developed by micropropagation method had 7-fold carvone, 3-fold piperitone, 2-fold 3-octanone and 2-fold menthalactone. Compared to plants grown through natural cuttings. These results showed that the plants developed through micropropagation had several fold high amounts of essential metabolites generally used in natural and alternative medicine. This indicated that micropropagation method for mentha development is economically better than plants obtained through natural cuttings.