Am J Bot. 1998 Jan;85(1):30.
The potential for seed banks to significantly affect the genetic structure of populations was recognized nearly two decades ago. However, there has been little empirical work that examines the problem. In this study, we explore the possibility that the seed bank of a rare annual, Clarkia springvillensis, could act as a buffer against the genetic consequences of small population size. We examined the adult and seed bank cohort in three natural populations. The seed bank was surveyed by collecting soil cores twice during the growing season: postgermination and post seed set. The genetic constitution of the adults and seed bank cohort was determined by examining eight polymorphic isozyme loci via starch gel electrophoresis. The total genetic diversity in the seed bank (Ht = 0.355) was significantly higher than in the adults (Ht = 0.260). Additionally, Fst estimates of genetic differentiation among populations showed significantly less differentiation among population seed banks (Fst = 0.008) than among adults (Fst = 0.045). These results are in agreement with the expectation that seed banks would act to maintain genetic diversity in populations as well as have the effect of slowing differentiation of populations.
近二十年前，人们就已经认识到种子库有可能显著影响种群的遗传结构。然而，很少有实证研究探讨这个问题。在这项研究中，我们探讨了稀有一年生植物春美草（Clarkia springvillensis）的种子库是否可能作为缓冲，减轻小种群规模对遗传的影响。我们在三个自然种群中研究了成年个体和种子库群体。通过在生长季节两次收集土壤芯（种子萌发后和种子形成后）来调查种子库。通过淀粉凝胶电泳检测八个多态同工酶基因座，确定成年个体和种子库群体的遗传组成。种子库中的总遗传多样性（Ht=0.355）明显高于成年个体（Ht=0.260）。此外，种群间遗传分化的 Fst 估计值表明，种群间的种子库（Fst=0.008）比成年个体（Fst=0.045）的分化程度显著降低。这些结果与预期一致，即种子库可以维持种群的遗传多样性，并减缓种群的分化。
