Environmental factors affecting seed quality and germination of Mimosa ephedroides (Fabaceae), an endemic shrub from Monte Desert, Argentina.

Mimosa ephedroides is an endemic shrub from western Argentina. Knowledge on its germination response to different environmental factors contributes to an efficient use of this species in ecological restoration projects. This study aimed to examine different aspects of the species germination. Seed quality and dormancy, optimum germination temperature, effects of water and saline stresses (by using Mannitol and NaCl as osmotic agents, respectively) and of seed storage time on seed viability and germination, were evaluated. Experiments were carried out in controlled growth chambers. Germination percentage and mean germination time were calculated. Results showed that seeds of this species have high viability, low pre-dispersal loss and are non-dormant. Regarding abiotic factors, optimum germination temperature ranged from 20 to 30 °C, while high germination percentages were observed even at moderate and severe water stress (-1.12 MPa). Germination percentages decreased when salinity increased over 300 mM NaCl. For short periods (up to 36 months), seed storage at room temperature (18 °C) was adequate and did not affect seed viability or germination. These results constitute important contributions to the autecological aspects of this endemic species, supporting its incorporation in restoration projects and allowing efficient use of its seeds in direct seeding or seedling production. [ABSTRACT FROM AUTHOR]