Pairwise variation (V) of candidate reference genes as predicted by geNorm.

<p>Pairwise variation (Vn/Vn+1) for determination of the optimal number of reference genes predicted by geNorm and calculated between the normalization factors NFn and NFn+1, with a recommended cutoff threshold of 0.150. The pairwise variation was analyzed considering either all samples together (entire dataset) or in six separate subsets: ‘Santa Clara’ and ‘LAM 157’ (genotype subsets); control and inoculated (treatment subsets) and early and late (time after inoculation subsets).