Cohorts of arbuscular mycorrhizal fungi (AMF) in Vitis vinifera, a typical Mediterranean fruit crop.

In field conditions, grapevine roots normally are colonized by arbuscular mycorrhizal fungi (AMF). However, little is published, from either morphological or molecular studies, on the species composition of these symbionts in production vineyards. The AMF biodiversity of two Piedmont vineyards (at Neive and Lessona), characterized by different soil features, was investigated by morphological and molecular analyses. Several morphotypes were identified from the two vineyard soils. Community composition of AMF, both in soil and root samples, was then analysed with molecular approach to amplify a portion (550 bp) of AM fungal SSU rDNA. Phylogenetic analyses show a different distribution of sequences from the two sites in the main glomeromycotan groups. In the Neive site, the Glomeraceae group A is the only one well represented whereas more groups were found at Lessona. Among the more representative operational taxonomic units (OTUs), only one related to the Glomus irregulare phylotype was shared between the two vineyard soils. The data obtained in this work together with similar results in literature on this important fruit crop reinforce the concept that the general AMF assemblage structure and composition in vineyards might be influenced more by soil type than by host plant features (age, vegetative stages) or management practices.