Ongoing changes in temperature and precipitation regime may have strong impact on vulnerable life-history stages such as germination. Differences in germination patterns among species and populations may reflect their adaptation to conditions of their origin or may be determined by the phylogenetic constrains. These two effects are, however, rarely separated.All the germination patterns may also be modified by seed mass.We studied 40 populations of 14 species of Impatiens coming from Himalayas.Germination of seeds of different origin was tested in four target temperatures, three simulating original conditions plus a warmer climate change scenario. We also studied effect of shorter stratification and warmer temperature in combination as another possible effect of climate change.Original and target climate interacted and had strong impact on total germination, but not on germination speed and seed dormancy. Interaction between seed mass and original climate indicated different germination strategies in light and heavy seeds. Only seed mass was affected by phylogenetic relationships among the species, while germination response (with exception of T50) was driven primarily by climate of origin.This study is the first to show that the effect of seed mass interacts with original climate in determining species germination patterns under changing climate. The differences in seed mass are thus likely crucial for species ability to adapt to novel conditions as seed mass, unlike seed germination patterns, is strongly phylogenetically constrained. Further studies exploring how seed mass modifies species germination under changing climate are needed to confirm generality of these findings.

1Ongoing changes in temperature and precipitation regime may have strong impact on 2 vulnerable life-history stages such as germination. Differences in germination patterns among 3 species and populations may reflect their adaptation to conditions of their origin or may be 4 determined by the phylogenetic constrains. These two effects are, however, rarely separated. 5 All the germination patterns may also be modified by seed mass. 6 We studied 40 populations of 14 species of Impatiens coming from Himalayas. 7 Germination of seeds of different origin was tested in four target temperatures, three simulating 8 original conditions plus a warmer climate change scenario. We also studied effect of shorter 9 stratification and warmer temperature in combination as another possible effect of climate 10 change. 11Original and target climate interacted and had strong impact on total germination, but 12 not on germination speed and seed dormancy. Interaction between seed mass and original 13 climate indicated different germination strategies in light and heavy seeds. Only seed mass was 14 affected by phylogenetic relationships among the species, while germination response (with 15 exception of T50) was driven primarily by climate of origin. 16This study is the first to show that the effect of seed mass interacts with original climate 17 in determining species germination patterns under changing climate. The differences in seed 18 mass are thus likely crucial for species ability to adapt to novel conditions as seed mass, unlike 19 seed germination patterns, is strongly phylogenetically constrained. Further studies exploring 20 how seed mass modifies species germination under changing climate are needed to confirm 21 generality of these findings. 22 23 24 Kew words: phylogeny, seed mass, reproduction characteristics, original environment, target 25 environment 26 27 65 Seed traits including seed mass are strongly associated with phylogeny (Zhang, Du and 66 Chen 2004) (Moles et al. 2005) (Norden et al. 2009) (Barak et al. 2018). Phylogeny explains 67 considerable part of variance in germination among species (Bu et al. 2008) (Wang et al. 2009) 68 (Xu et al. 2014) (Seglias et al. 2018) and strong phylogenetic signal was found also in seed 69 dormancy traits (Dayrell et al. 2017). The likely cause is that phylogeny imposes limits to 70 variability in reproductive attributes within a clade because of similar developmental and design 71 constraints in related species (Ackerly and Donoghue 1995) (Figueroa and Armesto 2001).72However, to our knowledge, there is only one study focusing on the effects of within genus 73 phylogeny on species germination. It is based on seven species and showed that more closely 74 related species had more similar germination behavior and the authors point out that this subject 75 requires further attention (Carta, Hanson and Muller 2016a). Such knowledge is likely to 76 increase our understanding of evolution of species germination requirements. 77In this study, we explored germination response ...

Despite the existence of many studies on the responses of plant species to climate change, there is a knowledge gap on how specific climatic factors and their interactions regulate seed germination in alpine species. This understanding is complicated by the interplay between responses of seeds to the environment experienced during germination, the environment experienced by the maternal plant during seed development and genetic adaptations of the maternal plant to its environment of origin. METHODS:The study species (Anthoxanthum alpinum, A. odoratum) originated from localities with factorial combinations of temperature and precipitation. Seed germination was tested in conditions simulating the extreme ends of the current field conditions and a climate change scenario. We compared the performance of field-collected seeds with that of garden-collected seeds. RESULTS:A change to warmer and wetter conditions resulted in the highest germination of A. alpinum, while A. odoratum germinated the most in colder temperature and with home moisture. The maternal environment did have an impact on plant performance of the study species. Field-collected seeds of A. alpinum tolerated warmer conditions better than those from the experimental garden. CONCLUSIONS:The results demonstrate how knowledge of responses to climate change can increase our ability to understand and predict the fate of alpine species. Studies that aim to understand the germination requirements of seeds under future climates should use experimental designs allowing the separation of genetic differentiation, plasticity and maternal effects and their interactions, since all these mechanisms play an important role in driving species' germination patterns.