Optimum temperature for removal of physical dormancy in Malosma laurina (Anacardiaceae) seed is related to the melting temperature of the seed coat

摘要

Seed coat impermeability (physical dormancy) functions distribute seed germination in time, thereby increasing the chances of seedling establishment and survival (Rolston 1978). Fire is characteristic of the California chaparral where hard seeded Malosma laurina (Nutt.) Nutt. ex Abrams occurs. A short exposure to intense heat, simulating a fire event, enables subsequent seed germination in this species (Keeley 1991). The objective of this study was to determine whether thermally-stimulated changes inthe biophysical properties of the seed coat could be related to the optimum temperature for removal of physical dormancy.