Communities of arbuscular mycorrhizal fungi under Picconia azorica in native forests of Azores

Arbuscular mycorrhizal fungi (AMF) from the rhizosphere of the endemic Laurisilva tree, Picconia azorica , w ere characterised at two sites in each of two Azorean islands (Terceira and São Miguel). Forty-six spore morphotypes were found, and DNA extraction was attempted from individual spores of each of these. DNA was obtained from 18 of the morphotypes, from which a 1.5 kb long fragment of the nuclear ribosomal RNA gene (SSU-ITS-LSU) was sequenced. A total of 125 AMF sequences were obtained and assigned to 18 phylotypes. Phylogenetic analysis revealed sequences belonging to the families, Acaulosporaceae , Archaeosporaceae , Claroideoglomeraceae, Gigasporaceae and Glomeraceae . Phylotype richness changed between islands and between sampling sites at both islands suggesting that geographical and historical factors are determinant in shaping AMF communities in native forest of Azores. Ecological analysis of the molecular data revealed differences in AMF community composition between islands. In Terceira, the rhizosphere of P. azorica was dominated by species belonging to Acaulosporaceae and Glomeraceae , while São Miguel was dominated by members of Glomeraceae and Gigasporaceae . This is the first molecular study of AMF associated with P. azorica in native forest of the Azores. These symbiont fungi are key components of the ecosystem. Further research is needed to develop their use as promoters of plant establishment in conservation and restoration of such sites.