Ten putative reference genes for qRT-PCR data normalization have been identified in apple.
Stages of bud to fruit development and samples under biotic stresses were analyzed.
PCR efficiencies of all the genes were found to be ranging between 94% and 107.6%.
PP2A, RPL2 and GAPDH were found to be stable reference genes across the samples.
The 18S rRNA, β-tubulin and ubiquitin were found to be the least stable genes.