Aerial seed bank affects germination in two small-seeded halophytes in Arab Gulf desert

摘要

Aerial seed banks protect seeds against granivores, help seed dispersal over time and maintain seeds in a favorable microhabitat. We hypothesized that the aerial seed bank in maternal tissues could protect halophyte seeds from lethal salinity effects of soils. Effects of aerial (in plant canopy) and room-temperature (lab) storage on subsequent germination behavior were assessed for two small-seeded halophytes: Halocnemum strobilaceum (known to be salt tolerant, with a short-term aerial seed bank -less than 9 months) and Halopeplis perfoliata (less salt tolerant, with a long-term aerial seed bank more than 17 months). Seeds were germinated in different salinities in both light/dark regime and darkness treatments. Ungerminated seeds from the different salinities were transferred to distilled water to assess their ability to recover germination capacity. Salinity tolerance during germination was much greater in H. strobilaceum, compared to H. perfoliata. Storage in the aerial seed bank resulted in significant germination-reduction in H. strobilaceum, but not in H. perfoliata. In H. strobilaceum aerial-stored seeds were less tolerant of the salinity than were the room-temperature-stored seeds. These results support the notion that an aerial seed bank protects salt-sensitive seeds from effects of high soil salinity, especially in species that have short-term aerial seed banks. (C) 2015 Elsevier Ltd. All rights reserved.