A study on tansy chemotypes.

According to Scheu (5), a "pure chemical race" is defined using one oil component, which can be unequivocally considered as the main component. However, another way of defining a chemotype is to observe the whole peak distribution of the chromatogram (6). For example, following crossings between camphor and thujone chemotypes, the thujone types are divided into two different thujone types, thujone A and B (3,4). In this study, 80 per cent of the progeny of the artificial crosses of tansy ( TANACETUM VULGARE L.) appeared to belong to so-called "well-defined chemotypes", in which the concentration of the main component varied between 41-99 per cent. The "well-defined chemotypes" were distributed among eight main groups: sabinene, thujone, umbellulone, camphor, bornyl acetate, alpha-pinene, 1,8-cineole, and germacrene-D. The sesquiterpene germacrene-D was identified for the first time in the present study in the essential oil of tansy. Most of these "well-defined chemotypes" were again divided into subgroups A and B. In addition to the "well-defined chemotypes", a number of "mixed chemotypes" were also detected in the crossings. Those chemotypes accounted for 20 per cent of the whole crossing material.