Pooled Ectomycorrhizal Root Tips Targeted Locus (Loci)

Soil cores were collected from 72 forest plots (20x40 m) evenly divided into four treatments (elevated pH, elevated P, elevated pH+P, and untreated control) across 2 physiographic regions of Ohio. Each region contained 36 plots within 3 forests. Within each plot, ten cores were sampled 1-m from the base of an adult tree. Cores were sieved to separate roots and soil and root tips that were visually confirmed to be colonized by ectomycorrhizal fungi were pooled into single composite samples for each plot. Genomic DNA was extracted from the pooled root tips from each plot and the primer set ITS1-F/ITS2 was used to amplify the ITS1 region of the rRNA gene. A set of 24 Multiplex Identifiers were used to separate sequence reads into treatment x forest x region combinations and sequencing was completed on the GS-FLX 454 System.