Seedling survival and seed size: a synthesis of the literature

Abstract

Summary1 Large-seeded species have long been known to have higher survivorship during establishment than small-seeded species. Here, we assessed the size of this advantage by compiling published data on survival through seedling emergence, seedling establishment and sapling establishment. 2 We found no relationship between seed mass and survival through the transition from viable seed in or on the soil to newly emerged seedlings ( P = 0.47, n = 33 species). 3 Synthesis of data from experimental studies on the advantages of large-seeded species establishing under particular hazards (such as shade, drought or herbivory) confirmed that seedlings of large-seeded species perform better than those of small-seeded species in most situations. However, the magnitude of this advantage was not sufficient to counterbalance the greater number of seeds produced by small-seeded species m − 2 of canopy outline year − 1 . 4 Synthesis of data from field studies of populations under natural conditions also showed that large-seeded species have higher survival through early seedling establishment than small-seeded species ( P = 0.006, n = 112 species). However, the magnitude of this advantage would only be sufficient to counterbalance the greater number of seeds produced by small-seeded species m − 2 of canopy outline year − 1 if mortality continued at the same rate for some time. 5 The time required for a species with 10-fold larger seeds to recoup the advantage gained by a smaller-seeded species during seed production ranged from 8.8 weeks for the smallest seeded species in the data set, up to an implausible 4.2 years for the largest-seeded species. Thus, while large-seeded species do have a survival advantage over small-seeded species during seedling establishment, the available evidence suggests that advantages must also accrue during other stages in the life cycle. One possibility is that the greater seed production of small-seeded species (m − 2 of canopy outline year − 1 ) is partly offset by larger canopies and longer reproductive life spans in large-seeded species.

A herbicide-resistant ACCase 1781 Setaria mutant shows higher fitness than wild type

“…Lower seed size could cause lower seed survival and lower emergence rate (Moles and Westoby, 2004). Although the backcrossed isogenic material studied here was not typically weedy, lower seed size caused lower emergence rates in field evaluation, which may reveal the behaviour of the wild R green foxtail parent.…”

The repeated evolution of large seeds on islands

“…Evidence also suggests that larger seed sizes increase plant survival at later-life stages (e.g. sapling stage; [4]). …”

“…Seedling survival is directly influenced by seed size [4,5], and many functional traits covary with the size of seeds. These traits include dispersal mode, growth form, specific leaf area and seed number [6,7].…”

Fitness costs linked to dinitroaniline resistance mutation in Setaria

“…The difference of growth kinetics makes it less adapted to grow with the crop canopy, which results in receiving less light. The difference of seed weight makes it less suitable to develop seedlings in adverse conditions or results in smaller seedlings, thus possibly influencing the chance of reaching the adult stage and even reducing the adult reproduction (Moles and Westoby, 2004). The persistence of the trifluralin-resistant type in non-treated fields over 7 years (Andrews and Morrison, 1997) could be interpreted as the lack of S alleles in populations strongly submitted to the previous repeated treatments.…”