Inter- and intra-specific difference in the effect of elevation and seed mass on germinability of eight Allium species

Abstract In this study, the inter- and intra-specific variability in seed mass and germination of eight Allium species (A. ramosum, A. sikkimense, A. polyrhizum, A. macranthum, A. beesianum, A. cyaneum, A. przewalskianum, A. chrysanthum), and eight populations of Allium chrysanthum from an alpine meadow were investigated with and without considering the effects of temperature and elevation. The results showed that seed mass and germination traits had significant differences among species or populations. Allium species at higher elevation tended to produce smaller seeds, but intersite differences in seed mass among populations of A. chrysanthum did not show any relationship with increasing elevation. Seed germination across species and populations had different responses to elevation. Germination percentage (GP) significantly decreased with the increased elevational gradients among species when the effect of seed mass was controlled statistically, while the germination rate (GR) among populations was induced by increased elevation. Higher temperatures promoted seed germination among populations, but not among species. The relationship between germination and elevation, or and seed mass, had little response to temperature regimes. Smaller seeds germinated greatly, this negative correlation between seed mass and germination was likely to be enhanced by elevation among species due to the strong effect of elevation on seed mass. Overall, we considered that strong environmental effects and their interactions pressed on the seed mass and germination of species of Allium and populations of A. chrysanthum.