Small isolated plant populations are one of the consequences of fragmentation of natural habitats by humans. We asked what effect does the creation of smaller populations from larger ones has on the plant fitness-related trait seed germination. Using information on 119 species (142 species entries) in 50 families, we found that seeds in only 35.2% of the species entries from larger populations germinated to higher percentages than those from smaller populations. In the other entries, seeds from large and small populations germinated equally well (57.7% of total entries) or seeds from small populations germinated better (7.0% of total entries) than those from large populations. These results indicate that population size is not a reliable predictor of seed germinability. Furthermore, there was little relationship between seed germination and either seed mass, genetic diversity or degree of population isolation, or between population size and genetic diversity.

小型孤立植物种群是人类破坏自然栖息地的后果之一。我们询问从较大种群中产生较小种群对植物适应性相关性状种子萌发有何影响。利用 50 个科 119 个物种（142 个物种条目）的信息，我们发现来自较大种群的物种条目中只有 35.2% 的种子发芽率高于来自较小种群的物种。在其他条目中，来自大群体和小群体的种子发芽效果相同（占总条目的 57.7%），或者来自小群体的种子比来自大群体的种子发芽得更好（占总条目的 7.0%）。这些结果表明种群大小并不是种子发芽率的可靠预测指标。此外，种子发芽与种子质量、遗传多样性或种群隔离程度之间，或者种群大小与遗传多样性之间几乎没有关系。