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Seed reserves play vital roles in seed germination and seedling growth and their variation may be related to various environment factors, plant traits and phylogenetic history. Here, the evolutionary correlation associated with seed mass and altitude and carbon (C), nitrogen (N) and phosphorus (P) allocation of seeds among 253 alpine herbaceous plants was tested. In this study, phylogeny had strong limitations on nutrient allocation of seeds across species, and species from younger phylogenetic groups tended to have higher N and P contents, which might be considered as the evolutionary selection of seed plants. Higher seed N and P content would help seedlings to gain more survival chance and stronger competitive capacity, and their progeny would be more likely to be preserved. When phylogeny was considered, altitude only had a significant positive effect on P content, but the negative effects on seed mass were all expressed. The independent effects of altitude and seed mass suggest that the nutrient allocation of seeds might be affected by both environment and plant traits. In addition, altitude and seed mass displayed partial overlapping effects on nutrient allocation of seeds. The negative effects of seed mass were affected slightly by altitude, whereas altitude only had a significant positive effect on P content when seed mass was controlled. Above all, seed P content showed obvious and general correlations with seed mass, altitude and age of clade, which indicated that higher seed P content might be an adaptive selection of species associated with growth and survival of progeny. [ABSTRACT FROM AUTHOR]

Seed shape and seed volume are functionally important traits which are associated with seed germination. To study the ecological and evolutionary significance of seed shape and volume in relation to germination, a database comprising seed information for 383 species within 50 families from an alpine meadow on the eastern Qinghai-Tibet plateau was compiled. The independent and interactive effects of seed traits on germination and whether these effects are controlled by phylogeny are discussed. The results show the following: (1) Elongated seeds had higher percentage and faster speed of germination than compact seeds whereas smaller seeds tended to have higher germinability compared to larger ones; (2) Seed volume and shape evolved together but had independent effects on seed germination. Seed volume had no significant influence on seed germination among species with compact seeds, but had a significant effect on those among species with elongated seeds; seed germination of larger seeded species was affected by seed shape, but not by seed volume. These results might be related to their predation pressure and ability to germinate from deeper soil layers. Lastly, (3) Phylogenetic conservation plays an important role in the co-evolution of seed traits and germination characteristics. Species with similarly shaped seeds on a large scale might reflect a common selective pressure, but related species within a family might be more dependent on phylogenetic conservation. [ABSTRACT FROM AUTHOR]