Essential oil variations in different Perilla L. accessions: chemotaxonomic implications

In 2006, 26 accessions (mainly from Sichuan province, China) in one species and two varietal species among the genus Perilla L. were collected, and the essential oils (EOs) of their fresh leaves during the flowering period were analyzed by the GC-MS method in 2007. In total, 49 components could be identified. The results showed that eight chemotypes could be identified as follows: PK(perillaketone), DLP (D-limonene and piperitone), PT (piperitenone), MS (myristicin), AL (apiol), EM (elemicin), DEK (dehydroelsholtzia ketone) and PA (perilla aldehyde). Of them, chemotype DLP, AL and DEK were reported for the first time; DLP and AL were found only in the accessions from Sichuan province, China. In our study, the EOs of P06-1Z and P06-28 were investigated at several stages during growing. Taking into account the variability of the two accessions during the year, the seasonal influence on the main constituents could not change the status of the different chemotypes distinguished or enhance the veracity of the differentiation of eight chemotypes. The results also suggested that it may not always be possible to establish a correlation between the traditional morphological taxonomy and chemotypes.