A multiple RT-PCR assay for simultaneous detection and differentiation of latent viruses and apscarviroids in apple trees.

•New primers specific for ASGV and ASPV were designed based on conserved sequence region identified in updated virus genome sequences.•Newly designed primers for an internal amplification control, EF-1α, were used to improve the accuracy of PCR reactions.•The multiplex RT-PCR could simultaneously detect both viruses and viroids in field-collected apple samples for practical disease diagnosis.