
Seasonal periodicity of seed germination and its relationship to seasonal changes in temperature and soil moisture have been well studied in seeds of species with physiological dormancy. However, relatively little information is available on the role of these environmental factors in controlling the germination of seeds with physical dormancy. In a new study published in AoB PLANTS, Liu et al. determined whether Eremosparton songoricum (a perennial semi-shrub that inhabits the cold desert and produces seeds that show physical dormancy) exhibits seasonal periodicity of seed germination. They also investigated the relationship between seed dormancy break and soil temperature and moisture. To the authorsβ knowledge this is the first study to document seasonal periodicity in seed germination in a cold desert species with physical dormancy and to identify the mechanism (at the whole-seed level) of its occurrence.