Influence of mother plant and scarification agents on seed germination rate and vigor in Retama sphaerocarpa L. (Boissier)

Research ArticleThe aim of this study was to optimize nursery production of Retama sphaerocarpa (Fabaceae), an important shrub species characterized by a seed coat dormancy hindering germination, and used in the restoration of degraded arid and semi-arid areas. To assess the influence of scarification agents and mother plant effect on germination rate and seedling vigor, a germination test with fresh seed was performed in a germination chamber using a factorial design with two fixed factors (mother plant effect and scarification agent). Fresh seeds were scarified by sulphuric acid (96% concentration, 60 min) and hot water (80 °C, 30 sec) and their germination compared with untreated control seeds. Scarification of seeds using sulphuric acid has proven the best method to enhance germination of this species, achieving the highest germination rate (>79%) and the best vigor index. Differences between seed lots from different mother plants were statistically significant and could influence seed germination success. We suggest that effectiveness of hot water scarification method may be improved by additional time of seed immersion. Owing to its potential for use in land restoration, bioenergy production and ornamental purposes, increment of commercial demand of this species is expected in the near future