Pairwise correlation analyses were performed for all assayed genotypes (a) and the 10 best genotypes for biomass yield (b). The upper panel above the diagonal shows Pearson’s correlation coefficients, p-value and regression coefficient. The lower panel below the diagonal gives their scatter plot. (SSTD = Saccharification standardized values under CNAP conditions, VS = Saccharification standardized values under IAS-CSIC conditions, Kg_ha = estimated weight of straw by hectare, Eth1 = Theoretical ethanol calculated with CNAP’s saccharification values and estimated biomass, Eth2 = Theoretical ethanol calculated with IAS-CSIC’s saccharification values and estimated biomass, ILPave = Average for straw wall thickness for largest internode, PePave = Average for straw wall thickness for peduncle, and Grain_Y = grain yield).