Lane 1 – positive PSTVd control, lane 2 – deoxyribonucleic acid (DNA) marker pUC mix 8 (Thermo Fisher Scientific, SM0301), lane 12 – low range DNA marker (Thermo Fisher Scientific, SM0383), lanes 3 and 9 – samples from uninoculated plants (negative controls), lanes 4–8 and 10 – PSTVd-infected plants, lane 11a and 11b – water negative controls of PCR and RT with PCR reactions, respectively.