Stability of the nine Propylea japonica reference genes according to RefFinder.

A lower Geomean value indicates a more stable expression. β-actin (Actin), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), elongation factor 1 α (EF1A), α-tubulin (TUBA), ribosomal protein L4 (RPL4), ribosomal protein S18 (RPS18), heat shock protein 90 (HSP90), arginine kinase (ArgK), and vacuolar-type H+-ATPase subunit A (V-ATPase A).