Transgenerational effects of warming
Final germination of F1 seeds across germination strategies and soil
temperature treatments was > 90%, indicating that all
seeds produced were healthy and viable regardless of maternal soil
temperature. Germination temperature in contrast did affect offspring
germination (Fig. 3d). Warmer germination temperature led to longer time
to reach 50% germination and reduced germination of the non-dormant
seed fraction regardless of the germination strategy and maternal
warming (Table 2, Table S3). The absence of an interaction effect
between germination temperature and maternal warming indicates that
maternal soil temperatures did not affect the response to germination
temperatures, such that seeds produced from plants in warm soil did not
do better at higher germination temperatures than seeds produced from
plants in ambient soil. Across generations, germination strategies were
not only conserved across strategies (Fig. 3d), but also within
strategy, i.e. plants of staggered strategy produced seeds that had a
staggered germination strategy regardless of whether the maternal plant
was an autumn or spring germinant (Fig S2). In addition, the proportion
of dormant and non-dormant seeds within staggered populations was
relatively constant (Fig S2).