(A) Amino acid alignment of the coat protein (CP) regions of EU IC and CH2 IC. A marked level of variation is present in the N‐terminal region of the CP, indicated with a black line. Amino acids of CH2 origin comprising CP chimera 1 and CP chimera 2 are indicated with red lines 1 and 2, respectively. (B) Double antibody sandwich‐enzyme‐linked immunosorbent assay (DAS‐ELISA) absorbance data at 21 days post‐inoculation (dpi), showing systemic viral titres in Nicotiana benthamiana inoculated with EU IC, CH2 IC, CP chimera 1 and CP chimera 2. Healthy (HC) material is included for comparison. (C) Characteristic phenotypes presented by EU IC (a, f, k), CP chimera 1 (b, g, l), CP chimera 2 (c, h, m) and CH2 IC (d, i, n) in N. benthamiana at 21 dpi. Healthy control (HC) plant is given as a comparison (e, j, o). The single leaves depicted (k–o) are the third most developed leaves from the apex of the plant.