Number of infected HD285 plants (pvr23/pvr23) after inoculation by four Potato virus Y (PVY) inocula [SON‐1 and SON‐2, corresponding to SON41p, and CI‐1 and CI‐2, corresponding to the cylindrical inclusion (CI) chimera] and haplotype of the PVY populations. These haplotypes were determined by the consensus sequence of the genome‐linked viral protein (VPg) coding region and named after the observed amino acid substitutions compared with the VPg of SON41p, which is identical to that of the CI chimera. Letters denote homogeneous groups using Fisher's exact test at the 0.05 type‐I error threshold (corresponding to a 0.0085 type‐I error threshold after Bonferroni correction for multiple tests). Each type of VPg mutation was searched for through the single nucleotide polymorphism (SNP) report issued from high‐throughput sequencing of the corresponding inoculum. The presence or absence of the substitution within inocula is highlighted in light grey and dark grey, respectively.