Germination Responses to Vegetation in Maternal and Progeny Environments

The conditions in which a seed germinates is crucial to the survival and fitness of the plant. The ability to regulate germination given certain conditions is thus extremely important. This research examines the plastic germination responses to neighbor-associated light cues in Arabidopsis thaliana within a natural population. Our results show that light-induced germination responses of seeds from different maternal lineages within a natural population are largely uniform in direction. Although seeds exhibited dormancy loss with after-ripening, seeds imbibed under a canopy had lower germination proportions than those imbibed under white light. With respect to maternal environment, our results associate higher germination proportions with denser, more crowded maternal canopies. The effect of these maternal light cues on germination were most apparent during periods of high dormancy, suggesting that seeds become less selective over time as they after-ripen. Interestingly, the maternal and progeny cues are diametric to each other, with maternal cues seeming to encourage germination among neighbors while progeny cues respond negatively to canopies.