The number of gene SNPs discovered is significantly correlated to genome coverage of reads mapped to reference sequences. Random samples of SOLiD genomic reads with ~2X (1 run of SOLiD sequencing), ~4X (2 runs), ~6X (3 runs), ~8X (4 runs) and ~10X (5 runs) genome equivalents were used for SNP discovery. The values of genome coverage were estimated based on AS75 reads mapped to the annotated Roche 454 gene reads (Figure 2). The genome coverage of 10.7X (Table 6) based on this method is equivalent to 26.57X (Table 1) which was estimated based on the 4.02 Gb genome size of Ae. tauschii.