Effect of Ploidy Level on the Nuclear Genome Content and Essential Oil Composition of Anise Hyssop (Agastache foeniculum [Pursh.] Kuntze)

Abstract

Anise hyssop (Agastache foeniculum) is one of the important medicinal-ornamental plant species. In medicinal plants, polyploidy induction is usually associated with an increase in total nuclear genome content and a change in the quality and quantity of important medicinal compounds. In the present investigation, flow cytometry was used to compare the nuclear genome content of diploid and tetraploid plants of anise hyssop. The essential oils (EOs) of different ploidy levels, obtained by hydro-distillation method, were analyzed by GC and GC-MS instruments. The results showed the total nuclear genome of tetraploid and diploid plants was 2.15±0.001 pg and 1.06±0.02 pg, respectively. The change in ploidy level also significantly (P≤ 0.05) affected the EO content and most of its components. The percent of EO in diploid and tetraploid plants was 1.32 ±0.1 and 2.78± 0.1, respectively. The proportion of Methyl cavicol, which is the major EO component of anise hyssop, significantly (P≤ 0.05) increased in tetraploid plants (81.02%) compared to the diploids (78.75 %). The changes in the other chemical constituents of diploid and tetraploid plants are also discussed in the paper.