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).