2002) or ectomycorrhizal root tips (Izzo et al. 2005; Menkis et al. 2005; Rosling et al. 2003; Urban et al. 2008), further pointing to an obligate-biotrophic selleck kinase inhibitor lifestyle, which was already proposed by Porter et al. (2008). Such a direct dependence Tozasertib concentration of the fungus on living plants could be the reason for the hitherto inability to cultivate SCGI fungi. Fierer et al. (2007) suggested

that diversity is independent of soil parameters but an intrinsic feature of microbe types, the fungal specific Simpson’s diversity index being 134 ± 39. This value is however far above the values found in our study (7.37–28.09), in Brazilian soy bean plantation soil (2.87; de Castro et al. 2008), Scottish grassland soil (3.62–7.50; Anderson et al. 2003) or soil with mixed grass-legume-shrub vegetation in Tennessee (2.56–41.67; Castro et al. 2010). Underestimation of diversity indices due to

smaller sizes of libraries is unlikely to be the cause for this discrepancy, since predictions for the diversity indices of soils M, N, P, R and T stabilised after analysis of a maximum of 50 sequences. This is in good agreement with a comparative evaluation of diversity indices by Giavelli et al. (1986), who found that Simpson’s diversity index is least sensitive to small sample size. While the diversity in our study is potentially underestimated due to the use of RFLP for clone selection, even lower diversity indices were found in published studies for grassland (Anderson et al. 2003)

and arable (de Castro et al. 2008) soil by directly sequencing SSU libraries without preselection by RFLP (see Table 1), Demeclocycline an approach adopted at larger scale by Fierer AZD1480 purchase et al. (2007). Underestimation of diversity at the species level by analysing SSU libraries is expected since the phylogenetic resolution of the fungal SSU is commonly thought to be restricted to the genus or family level but not to be sufficient for species identification (Anderson and Cairney 2004; Seena et al. 2008). More comparative studies are needed to give a solid answer whether arable and grassland soils indeed sustain a lower fungal diversity compared to desert, prairie or rainforest soils, which are the ecosystems studied by Fierer et al. (2007). Our study provides a fungal community inventory of agricultural soils and reveals the most prominent species. Considering, however, the known seasonal dynamics of soil fungal communities and the diversity of agricultural practices, further studies are needed to extend and corroborate the presented initial findings. At least at the regional scale some general conclusions can be drawn from this study, i.e. (i) different agricultural soils harbour common fungal taxa from the species to the phylum level; (ii) the fungal biodiversity of our four investigated arable soils was in a similar range as one investigated and one reference grassland soils, and (iii) SCGI fungi seem to be absent from agricultural soils.