Finally, we investigated the transgenerational effects of soil salinity in matched environments. To this end, F1 progeny from parents exposed to increasing NaCl concentrations in the soil were analysed for root growth inhibition on agar medium supplemented with 50 mM and 100 mM NaCl, which is a common method to quantify salt tolerance in Arabidopsis (Verslues et al., 2006; Claeys et al., 2014). F1 populations from differently treated parents showed small but statistically significant differences in root growth on agar medium containing 0 mM and 50 mM NaCl (Fig. S4a), which were absent in the F2 generation (Fig. S4b). However, these differences in root growth appeared non-adaptive, since the degree of NaCl-induced root growth inhibition compared to roots on control plates (0 mM NaCl) was similar between populations from all parental treatments (Fig. 5a,b and Fig. S4c,d). Thus, under our conditions, progeny from salt-stressed plants did not express TAR in matched environments.