Ajit K. Shasany, Soni Gupta, Mahesh K. Gupta, Anil K. Singh, Ali A. Naqvi and Suman P. S. Khanuja*

Abstract: Essential oil components of 20 Indian peppermint accessions were analyzed through GC and GC/MS and compared with the reported components found in oil samples of different countries (22 locations of 19 countries) to check the commercial potential of the germplasm collection. The comparative oil component analyses revealed the close relation of P4 and P5 (Indian collections) with Chinese and P9 to Japanese peppermint. Some of the analyzed samples (P6, P8, P11 and P17) were close to American, Canadian, European and South African oils. Essential oil profiles of Indian accessions P10, P14, P19 and P20 were quite different from others as revealed by component plot analysis. In addition to the similarities, distinct chemotypes in the germplasm were detected with unique essential oil component profiles, which have been discussed in details in this investigation. Further, Amplified fragment length polymorphism (AFLP) analysis of these 20 Indian accessions differentiated them genetically with a diversity ranging between 17–95%.

Peppermint (Mentha x piperita), one of the hybrids of Mentha, is an important essential oil yielding crop of the Lamiaceae family. The oil and its constituents have been used since time immemorial as a flavoring agent as well as for its medicinal properties. The popularity of the plant gained momentum slowly from the herbal gardens of monasteries and churches in the medieval age through the kitchen gardens in the nineteenth century, to its present day large-scale cultivation and commercial production of the essential oil, which is variously used in the cosmetics, pharmaceuticals, food, confectionery and liquor industries (1). It is native of Mediterranean region, but the distillation of mint to produce an oil was started in England in 1750, where it was cultivated in herb gardens in Mitcham (Surrey). From England, it spread to other European countries and was introduced to the United States in 1790. The cultivars of peppermint grown today in various European countries (Bulgaria, France, Hungary, Italy, Poland, Spain, former Yugoslavia), Argentina, former USSR, and the United States are the descendants of the English black mint (2). These cultivars have been developed through the acclimatization of the originally introduced English mint at various locations resulting in the altered oil profile as compared to its progenitor. Presently, the conservation of the available biodiversity and its proper documentation and authentication has been given a lot of impetus. This available biodiversity can be exploited in generating high yielding varieties with better agronomic traits/ desired pool of secondary metabolites. Taking this in view, the Indian peppermint germplasm was analyzed genetically by amplified fragment length polymorphism (AFLP) to develop molecular markers for the authentication of the genotypes which can be exploited in future for variety development initiatives. The chemotypic profiles of these genotypes were compared with those from other countries as reported in literature to assess the tendencies of these chemotypes towards peppermint of other countries with an objective to assess the commercial potential.