Occurrence of Glomeromycota spores and some arbuscular mycorrhiza fungal species in arable fields in Sweden

Fungi within the phylum Glomeromycota were investigated in arable fields throughout Sweden. Sweden is located between 55° and 69° North. The fungi within this phylum form arbuscular mycorrhizal symbiosis with plant roots. Sampling of soil was carried out to a depth of 30 cm in the rhizosphere. Arbuscular mycorrhizal fungi were found at all 45 sampling sites, at densities between 3 and 44 spores per g dry weight of soil. No significant differences in spore densities were found between different agro-climatic zones or between semi-natural grassland and ploughed fields. Our study revealed that the upper half (0-15 cm) of the soil profiles had significantly more spores than the lower half (15-30 cm). Spores from eight sampling sites were identified from the indigenous soils. Almost 90% were shown to belong to the genus Glomus . The other genera found were Gigaspora and Scutellospora .