Local diversity of native arbuscular mycorrhizal fungi differentially affects growth and nutrition of three crop plant species

Functional diversity of arbuscular mycorrhizal fungi (AMF), which plays key roles in plant growth and nutrition, has been rarely investigated by means of whole native AMF communities. A distinctive field site within the UNESCO Biosphere Reserve “Selva Pisana” hosting the AMF highest species richness detected in a single area, with 58 AMF species and 14 genera, was identified as a “hot-spot” of AMF diversity1. Here, the soil from such a site, harbouring its native AMF communities, was collected from 6 plots showing uniform chemical-physical characteristics and used to grow three plant species (Allium cepa, Lactuca sativa and Capsicum annuum), which were evaluated for biomass, P and N contents. AMF communities in the roots of plants producing the most contrasting growth and nutritional responses were analyzed by constructing libraries from AML1/AML2 amplicons and sequencing the relevant clones. AMF species common to agricultural soil, such as Funneliformis mosseae, Claroideoglomus etunicatum and Rhizoglomus spp. and other sensitive to agricultural practices, such as Racocetra fulgida were identified. The highest AMF species richness and the most evenly distributed AMF community composition were detected in the roots of plants showing the best growth performances. Moreover, a distinctive host preference was found in some AMF species. Our work demonstrates that the local diversity of native AMF communities may strongly affect plant responses, a finding to be further explored in the years to come, in order to exploit the potential benefit of mycorrhizal symbionts in sustainable agroecosystems.