Temperature but not moisture response of germination shows phylogenetic constraints while both interact with seed mass and lifespan

Abstract

To cite this version:Fabien Arène, Laurence Affre, Aggeliki Doxa, Arne Saatkamp. Temperature but not moisture response of germination shows phylogenetic constraints while both interact with seed mass and lifespan. Seed Science Research, Cambridge University Press (CUP), 2017, 27 (02), pp.110 -120. AbstractUnderstanding how plant traits interact with climate to determine plant niches is decisive for predicting climate change impacts. While lifespan and seed size modify the importance of germination timing, germination traits such as base temperature and base water potential directly translate climatic conditions into germination timing, impacting performance in later life stages. Yet we do not know how base temperature, base water potential, seed mass, lifespan and climate are related. We tested the relationships between base temperature and base water potential for germination, seed size and lifespan while controlling for bioclimatic regions. We also quantified the phylogenetic signal in germination traits and seed size using Pagel's λ. We used a worldwide data set of germination responses to temperature and moisture, seed size and lifespan of 240 seed plants from 49 families. Both germination temperature and moisture are negatively related to seed size. Annual plants show a negative relation between seed size and base water potential, whereas perennials display a negative relation between base temperature and seed mass. Pagel's λ highlighted the slow evolution of base temperature for germination, comparable to seed mass while base water potential was revealed to be labile. In the future, base water potential and seed mass can be used when moisture niches of plants are to be predicted. Lifespan, seed size and base temperature should be taken into account when analysing thermal limits of species distributions.

Variation in the seasonal germination niche across an elevational gradient: the role of germination cueing in current and future climates

“…In a study of germination responses to temperature and moisture across 240 species and 49 families across the globe, Arene et al. () found negative correlations among seed and germination traits, as well as evidence for phylogenetic constraint in temperature responses. Such patterns could constrain the potential for evolutionary response to increased temperatures with climate change.…”

“…Of course, evolutionary response depends on standing genetic variation, heritability, and constraints on response to selection (Antonovics and Vantienderen, 1991;Kopp and Matuszewski, 2014). In a study of germination responses to temperature and moisture across 240 species and 49 families across the globe, Arene et al (2017) found negative correlations among seed and germination traits, as well as evidence for phylogenetic constraint in temperature responses. Such patterns could constrain the potential for evolutionary response to increased temperatures with climate change.…”

A research agenda for seed‐trait functional ecology

“…The economic spectra of leaves and roots have their conceptual basis in the allocation of resources to alternative functions that cannot be optimized simultaneously (Wright et al ., ), but seeds may encompass functions independent of resource economic constraints (Liu et al ., ). For example, seeds with similar masses may have large variation in germination physiology and their response to environmental factors (Arène et al ., ) and germination timing might constitute an independent axis of variation compared to morphology and chemistry (Fig. ).…”

“…Notwithstanding early recognition of its importance (e.g. Martin, ; Grushvitzky, ), the phylogenetic signal of seed traits such as desiccation tolerance (Wyse & Dickie, ), dormancy (Willis et al ., ), embryoless seeds (Dayrell et al ., ), photo‐inhibition (Carta et al ., ), embryo size (Forbis et al ., ; Vandelook et al ., ) and germination temperature or moisture (Arène et al ., ) has only been recently quantified in such a way as to be accessible for statistical purposes. Indeed, many other seed traits may show correlations with phylogeny, and many more trait–trait relationships are likely to exist as well, for example between germination speed and seed persistence (Saatkamp et al ., ; Kadereit et al ., ).…”

“…Does the germination niche fit the new conditions? Seed traits could be used to delineate species boundaries by determining the germination niche (Rosbakh & Poschlod, 2014;Ar ene et al, 2017). Still, we need to better identify which seed and fruit traits are likely to drive species' geographical distributions, and how they can be linked together with vegetative traits in a mechanistic understanding of geographical range shifts (Gonz alez-Varo et al, 2017).…”