Dry-storage and light exposure reduce dormancy of Arabian desert legumes more than temperature

Abstract

Propagation and conservation of desert plants are assisted by improved understanding of seed germination ecology. The effects of dry-storage on dormancy and germination were studied in seven desert legumes. Mature seeds were collected in summer 2017 and germinated within one week of collection (fresh) and after six months (dry-storage) under two temperature and two light regimes. Seed weight of two species increased 22-55% within 24 hours of water imbibition but others increased ≤ 7%. Germination ranged from 0-32% in fresh and 2-92% in dry-stored seeds, indicating a mix of non- and physically-dormant seeds at maturity. Dry-storage at ambient room temperature was effective at relieving dormancy, though the extent was species-dependent. Germination percentage increased in response to light exposure during incubation, while the effect of temperature was species-dependent. This variable response to dormancy alleviation may assist to spread the population risk of seedling survival in the harsh and variable environment of the Arabian desert.