Seed mass and germination in an alpine meadow on the eastern Tsinghai–Tibet plateau

Abstract

In this study, we built up a database of 570 species from an alpine meadow on the eastern Tsinghai-Tibet plateau. We examined the correlation of seed mass and germination with phylogeny, habitat and altitude, and the relationship between seed mass and germination. We found that: habitats had no significant effects on seed mass and germinability, which was in accord with the former studies; there was a significant negative correlation between seed mass and altitude, as well as between germinability and altitude, which was opposite to most of the former studies; there was a significant negative correlation between seed mass and germinability, which was in contrast with other studies that have found a positive relationship, and seed mass could explain 24.1% of total variation in germinability; in GLM, family and genus accounted for 43.9% and 83.9% of total variation in seed mass, and 34.1% and 65.4% in germinability, respectively, thus, it was evident that seed mass and germinability were strongly related to phylogeny. We considered that seed mass and germination might be the result of both selective pressures over long-term ecological time and the constraints over long-standing evolutionary history of the taxonomic membership. We suggest that correlates of ecology and phylogeny should be taken into account in comparative studies on seed mass and germination among species.

Assessment of morpho-anatomical traits of red fescue (Festuca rubra L.) germplasm differing in origin

“…It is interesting to note that the average weight of 1000 seeds in both groups was the same. This finding supports the idea that within species seed mass is a remarkably constant characteristic (Bu et al, 2007). It is also noteworthy that Ukrainian populations of F. rubra had significantly longer lemmas (P < 0.05) than Latvian ones.…”

Life-History Responses to the Altitudinal Gradient

“…However, despite the fact that elevation gradients in seed mass have repeatedly been reported (Baker 1972;Blionis and Vokou 2005), findings were often conflicting and had not revealed any consistent pattern thus far. Although an increase in seed mass with elevation was reported by Pluess et al (2005), there is also evidence of negative relationships between seed mass and elevation supporting the 'energy constraints' hypothesis, which states that lower temperatures and shorter growing seasons at higher elevations may reduce resource acquisition and the energy available for seed development and seed provisioning (Baker 1972;Körner 2003;Bu et al 2007). Additionally, seed size is subjected to allometric constraints and thus determined by plant size variation with altitude.…”

Effect of phylogeny, life history and habitat correlates on seed germination of 69 arid and semi-arid zone species from northwest China

“…Comparative surveys have shown that germination behavior is also related to other life history traits such as seed mass (Mazer 1989;Shipley and Parent 1991;Jurado and Westoby 1992;Guo et al 2000;Pearson et al 2002;Bu et al 2007), seed dispersal (Willson and Traveset 2000) and life form (Gross 1984;Figueroa 2003). In addition, some of the variance in life history traits between species is associated with phylogeny (Mazer 1989(Mazer , 1990Leishman et al 1995;Figueroa and Armesto 2001;Figueroa 2003;Zhang et al 2004;Simons and Johnston 2006;Bu et al 2007), and this association is often attributed to phylogenetic constraints (Kochmer and Handel 1986). Therefore, to assess the role of natural selection on seed germination at the community level, we should take into account as many variables as possible when measuring the effect of any single variable.…”