Table 1.

Description of the variables used in this study.

Variable	Experiment	Number of DH lines	Plants per DH line	PVY inoculum*	Infection stage/date of measure	Reference
RB: frequency of resistance breakdown	1	151	60	CI chimera	Systemic/38 dpi†	Quenouille et al. (2014)
VA: level of virus accumulation	2	151	10	Mutant N of CI chimera	Systemic/36 dpi	Quenouille et al. (2014)
N e inoc: virus effective population size at inoculation	3	151	10‡	Mutant K of SON41p‐GFP	Inoculated cotyledon/5–6 dpi	Tamisier et al. (2017)
N e: virus effective population size during infection from inoculation to 21 dpi	4	84	8	SON41p mutants G, N, K, GK and KN	Systemic/21 dpi	This study
σ r: differential selection exerted on the virus population	4	84	8	SON41p mutants G, N, K, GK and KN	Systemic/21 dpi	This study

^*One or two letter codes for mutants correspond to amino acid substitutions in Potato virus Y (PVY) VPg (viral protein genome‐linked) allowing infection of plants carrying the pvr2 ³ resistance gene.

^†dpi, days post‐inoculation.

^‡10 plants × 2 cotyledons.