| Purple coneflower, Echinacea purpurea (L.) Moench, is an important phytomedicinal species, producing phenolics and alkamides which have medicinal properties. This study examined the contribution of arbuscular mycorrhizal (AM) colonization on the physiology and biochemistry of E. purpurea, alone or in combination with jasmonic acid (JA), and over time. It was hypothesized that AM colonization enhances growth, nitrogen assimilation and secondary metabolism in E. purpurea. It was also hypothesized that JA application alone, or in combination with AM colonization, and growth time increases the phytochemical content. To verify these hypotheses, three greenhouse experiments were performed with E. purpurea, with or without AM fungus, Glomus intraradices Schenck & Smith, and harvested after (1) 13 weeks of growth (2) 13 weeks and JA treatment and (3) five different growth periods starting from week four to fifteen. The overall results indicated that AM colonization significantly increased the mass of shoots and roots, the concentration of proteins in roots and most of the phenolics. Results also suggested that the effects of AM colonization and/or JA application are similar on the induction of phenolics. Furthermore, time was a main factor on the enhancement of the phytochemical content, of the alkamides found to be dominant in roots, and phenolics in shoots. Optimizing the growth by AM colonization represents an organic method of enhancing E. purpurea yield and phytochemical content. |
