Diversity of fungal symbionts in arbuscular mycorrhizas from a natural community

Abstract

summary The arbuscular mycorrhizal (AM) association between fungi in the order Glomales and the roots of a very wide range of vascular plants is of global ecological significance but has proved particularly intractable to study in the field. We have developed a reliable technique to identify the fungal symbionts in roots taken directly from natural communities. Selective Enrichment of Amplified DNA combines the use of recently‐developed specific DNA primers with a novel method based on the principle of subtractive hybridization to remove interfering plant‐derived DNA after amplification with the polymerase chain reaction. Using this technique we have shown that endomycorrhizas of bluebells ( Hyacinthoides non‐scripta ) sampled directly from a woodland habitat are multispceies communities of varying composition which contain at least three genera of mycorrhizal fungi. The technique works well on a range of plant species and should have wide application to the identification of other symbionts, including pathogens. A spore survey has indicated that two particular AM types are associated with bluebells and this observation corroborates the molecular data. The presence of a Glomus species in bluebell roots was not expected from the spore data.