Figure 3

The pairwise variations of 12 reference genes calculated by geNorm. The V of six series (total, rhizomes, flowers, leaves, seeds, topic tissues) were calculated. The 0.15 is a propositional cut-off value about pairwise variation value, an extra reference gene is not required for normalization when the number is below 0.15. Pairwise variation was analyzed to determine the optimal umber of reference genes, and used * to mark propositional cut-off value.