Seed mass and germination traits relationships among different plant growth forms with aerial seed bank in the sub-tropical arid Arabian deserts

摘要

Background: Seed mass and plant growth forms can affect dispersal syndrome that determines where seed is stored until germination, which can consequently determine germination requirements and the fate of emerged seedlings.Aims: This study aimed to assess the relationships between seed mass, germination rate and light and temperature requirements during germination of 23 desert plants with an aerial seed bank.Methods: Freshly collected seeds and those stored for 9 months at room temperature and enclosed within plant parts in the field were germinated in three growth chambers adjusted to three temperatures and two light regimes.Results: Trees and shrubs had significantly heavier seeds with greater dormancy compared to herbs. Germination at all storage conditions responded positively to light in herbs and germinated in both light and dark in shrubs and trees. Field storage enhanced light germination in trees, but not in shrubs and herbs. Germination rate index was greater for seeds of herbs and trees compared to those of shrubs. The relationships between seed mass and final germination in both light and dark regimes were positive in herbs but negative in shrubs.Conclusions: Growth form, seed size, storage condition can affect light, but not temperature, requirement of the studied plants.