Figure 6

Taxon associations inferred from co-occurrence analysis. (a) Distribution of P-values for Spearman’s correlation coefficients for taxon associations observed in the TOP metagenomic data. Colored (red and green) areas of the histogram represent taxon pairs showing statistically significant correlations. The position of the P-value for the hypothetical positive association between the ‘Megaviridae’ and ‘oomycetes’ taxonomic groups is indicated by a red triangle. (b) Correlated occurrence of 454 reads taxonomically assigned to the ‘Megaviridae’ and the ‘oomycetes’ groups by the BLAST-based 2bLCA method. Each dot corresponds to one of the 17 TOP samples analyzed. Axes represent the density of these reads (number of reads per Mbp) for each of the ‘Megaviridae’ and the ‘oomycetes’ groups.