The ecological and evolutionary significance of seed banks in Arabidopsis thaliana

Many studies of the genetic structuring of annual, selfing Arabidopsis thaliana populations on various geographical scales have been performed in recent years. Some studies conclude that local populations may contain relatively high amounts of genetic var iability both in phenotypic traits and putatively neutral markers. Earlier work has shown that Norwegian populations may often be characterized by less genetic drift than expected based on observed census number of individuals within years. In the presenc e of a viable seed bank, the effective number of individual plants present in a population in a period of several years may be much larger than the number found in each individual year. This implies that genetic drift could be reduced compared to a situat ion with only above-ground individuals present, and more genetic variability may be found within populations than what expected based on census numbers. We have found extensive and highly viable seed banks in the majority of studied Norwegian populations, and we hypothesize that A. thaliana seed banks play a significant demographic and evolutionary role. The aim of the outlined project is to explore the role of seed banks in Arabidopsis ecology and evolution, with a special emphasis on the role of seed ba nks in relation to genetic structuring. We are interested in determining how seed trait and seed bank characteristics influence the ecology and evolution of Arabidopsis.