Analysis of phenotypic plasticity of bud set in a Populus nigra full-sib family (POP5). Data were observed in two sites in Italy: Cavallermaggiore (CV) and Viterbo (VT). (a) Frequency distribution of the genotype relative ecovalence (%). The vertical dotted line separates the 17 most plastic genotypes, accounting 50% of the total G × E observed for the onset of growth cessation (date2.5). (b) Interaction patterns of the full-sib genotypes. The vertical black lines indicate the 17 most plastic genotypes. (c) Total duration of bud set process for 13 of these plastic genotypes that showed an interaction pattern with a positive slope CV-VT in terms of cumulative minimum temperature < 10°C (CMT10). Bars represent the duration from onset of growth cessation (date2.5) to the end of bud maturation (date0.5), measured in day of the year (DOY) in CV (white bars) and VT (grey bars). The CMT10 value corresponding to date2.5 is reported on the left of each bar.