Mycorrhizal colonization impacts on phenolic content and antioxidant properties of artichoke leaves and flower heads two years after field transplant.

Microcosm and field experiments were carried out in order to investigate the influence of mycorrhizal fungus inoculation on total phenolic content (TPC) and antioxidant activity, expressed as antiradical power (ARP), of artichoke (Cynara cardunculus L. var. scolymus F.) leaves and flower heads extracts. The establishment of mycorrhizal symbiosis was monitored in microcosm and field grown plants, and the persistence of the inoculated AMF in roots after two years’ growth in the field was assessed by fungal ITS sequencing. Both in the microcosm and in the field, marked increases in TPC and ARP were detected in leaves and flower heads of artichoke plants inoculated with the AM fungal species Glomus intraradices, either alone or in mixture with Glomus mosseae. After two years’ growth in the field ITS rDNA sequences clustering with those of G. mosseae and G. intraradices were retrieved only from inoculated plant roots. Our data show that mycorrhizal fungus inoculation may represent an efficient and sustainable strategy to improve productivity and enhance plant biosynthesis of secondary metabolites with health promoting activities.